display(1)display(1)NAMEdisplay - display an image on any workstation running X
SYNOPSISdisplay [ options ...] file [ [ options ...] file ...]
DESCRIPTION
Display is a machine architecture independent image
processing and display program. It can display an image
on any workstation screen running an X server. Display
can read and write many of the more popular image formats
(e.g. JPEG, TIFF, PNM, Photo CD, etc.). With display, you
can perform these functions on an image:
o load an image from a file
o display the next image
o display the former image
o display a sequence of images as a slide show
o write the image to a file
o print the image to a Postscript printer
o delete the image file
o create a Visual Image Directory
o select the image to display by its thumbnail rather
than name
o copy a region of the image
o paste a region to the image
o undo last image transformation
o half the image size
o double the image size
o resize the image
o restore the image to its original size
o refresh the image
o crop the image
o cut the image
o flop image in the horizontal direction
o flip image in the vertical direction
o rotate the image 90 degrees clockwise
o rotate the image 90 degrees counter-clockwise
o rotate the image
o shear the image
o trim the image edges
o invert the colors of the image
o vary the color brightness
o vary the color saturation
o vary the image hue
o gamma correct the image
o sharpen the image contrast
o dull the image contrast
o perform histogram equalization on the image
o perform histogram normalization on the image
o negate the image colors
o convert the image to grayscale
o set the maximum number of unique colors in the image
o reduce the speckles within an image
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o eliminate peak noise from an image
o detect edges within the image
o emboss an image
o segment the image by color
o simulate an oil painting
o simulate a charcoal drawing
o annotate the image with text
o draw on the image
o edit an image pixel color
o edit the image matte information
o composite an image with another
o add a border to the image
o surround image with an ornamental border
o add an image comment
o apply image processing techniques to a region of
interest
o display information about the image
o show a histogram of the image
o display image to background of a window
o set user preferences
o display information about this program
o discard all images and exit program
o change the level of magnification
o display images specified by a World Wide Web (WWW)
uniform resource locator (URL)
EXAMPLES
To scale an image of a cockatoo to exactly 640 pixels in
width and 480 pixels in height and position the window at
location (200,200), use:
display-geometry 640x480+200+200! cockatoo.miff
To display an image of a cockatoo without a border
centered on a backdrop, use:
display +borderwidth -backdrop cockatoo.miff
To tile a slate texture onto the root window, use:
display-size 1280x1024 -window root slate.png
To display a visual image directory of all your JPEG
images, use:
display 'vid:*.jpg'
To display a MAP image that is 640 pixels in width and 480
pixels in height with 256 colors, use:
display-size 640x480+256 cockatoo.map
To display an image specified with a World Wide Web (WWW)
uniform resource locator (URL), use
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display(1)display(1)display ftp://ftp.imagemagick.org/pub/ImageMagick/images/examples.jpg
OPTIONS-backdrop
display the image centered on a backdrop.
This backdrop covers the entire workstation screen
and is useful for hiding other X window activity
while viewing the image. The color of the
backdrop is specified as the background color.
Refer to X RESOURCES for details.
-border <width>x<height>
surround the image with a border of color. See
X(1) for details about the geometry specification.
The color of the border is obtained from the X
server and is defined as bordercolor (class
borderColor). See X(1) for details.
-cache threshold
megabytes of memory available to the pixel cache.
Image pixels are stored in memory until 80
megabytes of memory have been consumed. Subsequent
pixel operations are cached on disk. Operations to
memory are significantly faster but if your
computer does not have a sufficient amount of free
memory you may want to adjust this threshold value.
-colormap type
the type of colormap: Shared or Private.
This option only applies when the default X server
visual is PseudoColor or GrayScale. Refer to
-visual for more details. By default, a shared
colormap is allocated. The image shares colors
with other X clients. Some image colors could be
approximated, therefore your image may look very
different than intended. Choose Private and the
image colors appear exactly as they are defined.
However, other clients may go technicolor when the
image colormap is installed.
-colors value
preferred number of colors in the image.
The actual number of colors in the image may be
less than your request, but never more. Note, this
is a color reduction option. Images with less
unique colors than specified with this option will
have any duplicate or unused colors removed. Refer
to quantize(5) for more details.
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Note, options -dither, -colorspace, and -treedepth
affect the color reduction algorithm.
-colorspace value
the type of colorspace: GRAY, OHTA, RGB,
Transparent, XYZ, YCbCr, YIQ, YPbPr, YUV, or CMYK.
Color reduction, by default, takes place in the RGB
color space. Empirical evidence suggests that
distances in color spaces such as YUV or YIQ
correspond to perceptual color differences more
closely than do distances in RGB space. These
color spaces may give better results when color
reducing an image. Refer to quantize(5) for more
details.
The Transparent color space behaves uniquely in
that it preserves the matte channel of the image if
it exists.
The -colors or -monochrome option is required for
this option to take effect.
-comment string
annotate an image with a comment.
By default, each image is commented with its file
name. Use this option to assign a specific comment
to the image. Optionally you can include the image
filename, type, width, height, or other image
attributes by embedding special format characters:
%b file size
%c comment
%d directory
%e filename extention
%f filename
%h height
%i input filename
%k number of unique colors
%l label
%m magick
%n number of scenes
%o output filename
%p page number
%q quantum depth
%s scene number
%t top of filename
%u unique temporary filename
%w width
%x x resolution
%y y resolution
\n newline
\r carriage return
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For example,
-comment "%m:%f %wx%h"
produces an image comment of MIFF:bird.miff 512x480
for an image titled bird.miff and whose width is
512 and height is 480.
If the first character of string is @, the image
comment is read from a file titled by the remaining
characters in the string.
-compress type
the type of image compression: None, BZip, Fax,
Group4, JPEG, LZW, RLE, or Zip.
Use this option with -write to specify the the type
of image compression. See miff(5) for details.
Specify +compress to store the binary image in an
uncompressed format. The default is the
compression type of the specified image file.
-contrast
enhance or reduce the image contrast.
This option enhances the intensity differences
between the lighter and darker elements of the
image. Use -contrast to enhance the image or
+contrast to reduce the image contrast.
-crop <width>x<height>{+-}<x offset>{+-}<y offset>{%}
preferred size and location of the cropped image.
See X(1) for details about the geometry
specification.
To specify a percentage width or height instead,
append %. For example to crop the image by ten
percent on all sides of the image, use -crop 10%.
Use cropping to apply image processing options to,
or display, a particular area of an image.
Use cropping to crop a particular area of an image.
Use -crop 0x0 to trim edges that are the background
color. Add an x and y offset to leave a portion of
the trimmed edges with the image.
The equivalent X resource for this option is
cropGeometry (class CropGeometry). See X RESOURCES
for details.
-delay <1/100ths of a second>
display the next image after pausing.
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This option is useful when viewing several images
in sequence. 1/100ths of a second must expire
before the next image is displayed. The delay is
rounded to the nearest second. The default is to
display the image and wait until you choose to
display the next image or terminate the program.
-density <width>x<height>
vertical and horizontal resolution in pixels of the
image.
This option specifies an image density when
decoding a Postscript or Portable Document page.
The default is the same as the resolution of your X
server (see xdpyinfo(1)). This option is used in
concert with -page.
-depth value
depth of the image. This is the number of bits in
a pixel. The only acceptable values are 8 or 16.
-despeckle
reduce the speckles within an image.
-display host:display[.screen]
specifies the X server to contact; see X(1).
-dispose method
GIF disposal method.
Here are the valid methods:
0 No disposal specified.
1 Do not dispose between frames.
2 Overwrite frame with background color from header.
3 Overwrite with previous frame.
-dither
apply Floyd/Steinberg error diffusion to the image.
The basic strategy of dithering is to trade
intensity resolution for spatial resolution by
averaging the intensities of several neighboring
pixels. Images which suffer from severe contouring
when reducing colors can be improved with this
option.
The -colors or -monochrome option is required for
this option to take effect.
Use +dither to render Postscript without text or
graphic aliasing.
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display(1)display(1)-edge factor
detect edges with an image. Specify factor as the
percent enhancement (0.0 - 99.9%).
-enhance
apply a digital filter to enhance a noisy image.
-filter value
use this type of filter when resizing an image.
Use this option to affect the resizing operation of
an image (see -geometry). Choose from these
filters:
Point
Box
Triangle
Hermite
Hanning
Hamming
Blackman
Gaussian
Quadratic
Cubic
Catrom
Mitchell
Lanczos
Bessel
Sinc
The default filter is Lanczos.
-flip create a "mirror image" by reflecting the image
scanlines in the vertical direction.
-flop create a "mirror image" by reflecting the image
scanlines in the horizontal direction.
-frame <width>x<height>+<outer bevel width>+<inner bevel
width>
surround the image with an ornamental border. See
X(1) for details about the geometry specification.
The color of the border is specified with the
-mattecolor command line option.
-gamma value
level of gamma correction.
The same color image displayed on two different
workstations may look different due to differences
in the display monitor. Use gamma correction to
adjust for this color difference. Reasonable
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values extend from 0.8 to 2.3.
You can apply separate gamma values to the red,
green, and blue channels of the image with a gamma
value list delineated with slashes (i.e.
1.7/2.3/1.2).
Use +gamma to set the image gamma level without
actually adjusting the image pixels. This option
is useful if the image is of a known gamma but not
set as an image attribute (e.g. PNG images).
-geometry <width>x<height>{+-}<x offset>{+-}<y
offset>{%}{@}{!}{<}{>}
preferred size and location of the image window.
See X(1) for details about the geometry
specification. By default, the window size is the
image size and the location is chosen by you when
it is mapped.
By default, the width and height are maximum
values. That is, the image is expanded or
contracted to fit the width and height value while
maintaining the aspect ratio of the image. Append
an exclamation point to the geometry to force the
image size to exactly the size you specify. For
example, if you specify 640x480! the image width is
set to 640 pixels and height to 480. If only one
factor is specified, both the width and height
assume the value.
To specify a percentage width or height instead,
append %. The image size is multiplied by the
width and height percentages to obtain the final
image dimensions. To increase the size of an
image, use a value greater than 100 (e.g. 125%).
To decrease an image's size, use a percentage less
than 100.
Use @ to specify the maximum area in pixels of an
image.
Use > to change the dimensions of the image only if
its size exceeds the geometry specification. <
resizes the image only if its dimensions is less
than the geometry specification. For example, if
you specify '640x480>' and the image size is
512x512, the image size does not change. However,
if the image is 1024x1024, it is resized to
640x480.
When displaying an image on an X server, <x offset>
and <y offset> is relative to the root window.
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The equivalent X resource for this option is
geometry (class Geometry). See X RESOURCES for
details.
-interlace type
the type of interlacing scheme: None, Line, Plane,
or Partition. The default is None.
This option is used to specify the type of
interlacing scheme for raw image formats such as
RGB or YUV. No means do not interlace
(RGBRGBRGBRGBRGBRGB...), Line uses scanline
interlacing (RRR...GGG...BBB...RRR...GGG...BBB...),
and Plane uses plane interlacing
(RRRRRR...GGGGGG...BBBBBB...). Partition is like
plane except the different planes are saved to
individual files (e.g. image.R, image.G, and
image.B).
Use Line, or Plane to create an interlaced GIF or
progressive JPEG image.
-immutable
displayed image cannot be modified",
-label string
assign a label to an image.
Use this option to assign a specific label to the
image. Optionally you can include the image
filename, type, width, height, or other image
attribute in the label by embedding special format
characters. See -comment for details.
For example,
-label "%m:%f %wx%h"
produces an image label of MIFF:bird.miff 512x480
for an image titled bird.miff and whose width is
512 and height is 480.
If the first character of string is @, the image
label is read from a file titled by the remaining
characters in the string.
When converting to Postscript, use this option to
specify a header string to print above the image.
Specify the label font with -font.
-map type
display image using this Standard Colormap type.
Choose from these Standard Colormap types:
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best
default
gray
red
green
blue
The X server must support the Standard Colormap you
choose, otherwise an error occurs. Use list as the
type and display(1) searches the list of colormap
types in top-to-bottom order until one is located.
See xstdcmap(1) for one way of creating Standard
Colormaps.
-matte store matte channel if the image has one otherwise
create an opaque one.
-monochrome
transform the image to black and white.
-negate
replace every pixel with its complementary color
(white becomes black, yellow becomes blue, etc.).
The red, green, and blue intensities of an image
are negated. Use +negate to only negate the
grayscale pixels of the image.
-page <width>x<height>{+-}<x offset>{+-}<y
offset>{%}{!}{<}{>}
preferred size and location of an image canvas.
Use this option to specify the dimensions of the
Postscript page in dots per inch or a TEXT page in
pixels. The choices for a Postscript page are:
Letter 612x 792
Tabloid 792x1224
Ledger 1224x 792
Legal 612x1008
Statement 396x 612
Executive 540x 720
A3 842x1190
A4 595x 842
A5 420x 595
B4 729x1032
B5 516x 729
Folio 612x 936
Quarto 610x 780
10x14 720x1008
For convenience you can specify the page size by
media (e.g. A4, Ledger, etc.). Otherwise, -page
behaves much like -geometry (e.g. -page
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letter+43+43>).
To position a GIF image, use -page {+-}<x
offset>{+-}<y offset> (e.g. -page +100+200).
For a Postscript page, the image is sized as in
-geometry and positioned relative to the lower left
hand corner of the page by {+-}<x offset>{+-}<y
offset>. Use -page 612x792>, for example, to
center the image within the page. If the image
size exceeds the Postscript page, it is reduced to
fit the page.
The default page dimensions for a TEXT image is
612x792.
This option is used in concert with -density.
-quality value
JPEG/MIFF/PNG compression level.
For the JPEG image format, quality is 0 (worst) to
100 (best). The default quality is 75.
Quality for the MIFF and PNG image format sets the
amount of image compression (quality / 10) and
filter-type (quality % 10). Compression quality
values range from 0 (worst) to 100 (best). If
filter-type is 4 or less, the specified filter-type
is used for all scanlines:
0: none
1: sub
2: up
3: average
4: Paeth
If filter-type is 5, adaptive filtering is used
when quality is greater than 50 and the image does
not have a color map, otherwise no filtering is
used.
If filter-type is 6 or more, adaptive filtering
with minimum-sum-of-absolute-values is used.
The default is quality is 75. Which means nearly
the best compression with adaptive filtering.
For further information, see the PNG specification
(RFC 2083), <http://www.w3.org/pub/WWW/TR>.
-raise <width>x<height>
lighten or darken image edges to create a 3-D
effect. See X(1) for details about the geometry
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specification.
Use -raise to create a raised effect, otherwise use
+raise.
-remote string
execute a command in an remote display process.
The only command recognized at this time is the
name of an image file to load.
-roll {+-}<x offset>{+-}<y offset>
roll an image vertically or horizontally. See X(1)
for details about the geometry specification.
A negative x offset rolls the image left-to-right.
A negative y offset rolls the image top-to-bottom.
-rotate degrees{<}{>}
apply Paeth image rotation to the image.
Use > to rotate the image only if its width exceeds
the height. < rotates the image only if its width
is less than the height. For example, if you
specify -90> and the image size is 480x640, the
image is not rotated by the specified angle.
However, if the image is 640x480, it is rotated by
-90 degrees.
Empty triangles left over from rotating the image
are filled with the color defined as bordercolor
(class borderColor).
-sample geometry
scale image with pixel sampling. See -geometry for
details about the geometry specification.
-scene value
image scene number.
Use this option to specify an image sequence with a
single filename. See the discussion of file below
for details.
-segment value
eliminate clusters that are insignificant.
The number of pixels in each cluster must exceed
the the cluster threshold to be considered valid.
See IMAGE SEGMENTATION for details.
-sharpen <radius>x<sigma>
sharpen the image with a gaussian operator of the
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given radius and standard deviation (sigma).
-size <width>x<height>+<offset>
width and height of the image.
Use this option to specify the width and height of
raw images whose dimensions are unknown such as
GRAY, RGB, or CMYK. In addition to width and
height, use -size to skip any header information in
the image or tell the number of colors in a MAP
image file, (e.g. -size 640x512+256).
For Photo CD images, choose from these sizes:
192x128
384x256
768x512
1536x1024
3072x2048
Finally, use this option to choose a particular
resolution layer of a JBIG or JPEG image (e.g.
-size 1024x768).
-texture filename
name of texture to tile onto the image background.
-title string
assign a title to the displayed image.
Use this option to assign a specific title to the
image. This is assigned to the image window and is
typically displayed in the window title bar.
Optionally you can include the image filename,
type, width, height, or other image attributes by
embedding special format characters. See -comment
for details.
For example,
-title "%m:%f %wx%h"
produces an image title of MIFF:bird.miff 512x480
for an image titled bird.miff and whose width is
512 and height is 480.
-treedepth value
Normally, this integer value is zero or one. A
zero or one tells display to choose a optimal tree
depth for the color reduction algorithm.
An optimal depth generally allows the best
representation of the source image with the fastest
computational speed and the least amount of memory.
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However, the default depth is inappropriate for
some images. To assure the best representation,
try values between 2 and 8 for this parameter.
Refer to quantize(5) for more details.
The -colors or -monochrome option is required for
this option to take effect.
-update seconds
detect when image file is modified and redisplay.
Suppose that while you are displaying an image the
file that is currently displayed is over-written.
display will automatically detect that the input
file has been changed and update the displayed
image accordingly.
-verbose
print detailed information about the image.
This information is printed: image scene number;
image name; image size; the image class
(DirectClass or PseudoClass); the total number of
unique colors; and the number of seconds to read
and transform the image. Refer to miff(5) for a
description of the image class.
If -colors is also specified, the total unique
colors in the image and color reduction error
values are printed. Refer to quantize(5) for a
description of these values.
-visual type
display image using this visual type.
Choose from these visual classes:
StaticGray
GrayScale
StaticColor
PseudoColor
TrueColor
DirectColor
default
visual id
The X server must support the visual you choose,
otherwise an error occurs. If a visual is not
specified, the visual class that can display the
most simultaneous colors on the default X server
screen is chosen.
-window id
set the background pixmap of this window to the
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image.
id can be a window id or name. Specify root to
select X's root window as the target window.
By default the image is tiled onto the background
of the target window. If -backdrop or -geometry
are specified, the image is surrounded by the
background color. Refer to X RESOURCES for
details.
The image will not display on the root window if
the image has more unique colors than the target
window colormap allows. Use -colors to reduce the
number of colors. -window_group id exit program
when this window id is destroyed.
id can be a window id or name.
-write filename
write image to a file.
If file already exists, you will be prompted as to
whether it should be overwritten.
By default, the image is written in the format that
it was read in as. To specify a particular image
format, prefix file with the image type and a colon
(i.e. ps:image) or specify the image type as the
filename suffix (i.e. image.ps). See convert(1)
for a list of valid image formats. Specify file as
- for standard output. If file has the extension
.Z or .gz, the file size is compressed using with
compress or gzip respectively. Precede the image
file name | to pipe to a system command. If file
already exists, you will be prompted as to whether
it should be overwritten.
Use -compress to specify the type of image
compression.
The equivalent X resource for this option is
writeFilename (class WriteFilename). See X
RESOURCES for details.
In addition to those listed above, you can specify these
standard X resources as command line options:
-background, -bordercolor, -borderwidth, -font,
-foreground, -iconGeometry, -iconic, -mattecolor, -name,
or -title. See X RESOURCES for details.
Options are processed in command line order. Any option
you specify on the command line remains in effect until it
is explicitly changed by specifying the option again with
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a different effect. For example to display two images,
the first with 32 colors, and the second with only 16
colors, use:
display-colors 32 cockatoo.miff -colors 16 macaw.miff
By default, the image format is determined by its magic
number. To specify a particular image format, precede the
filename with an image format name and a colon (i.e.
ps:image) or specify the image type as the filename suffix
(i.e. image.ps). See convert(1) for a list of valid image
formats.
When you specify X as your image type, the filename has
special meaning. It specifies an X window by id, name, or
root. If no filename is specified, the window is selected
by clicking the mouse in the desired window.
Specify file as - for standard input. If file has the
extension .Z or .gz, the file is uncompressed with
uncompress or gunzip respectively. Precede the image file
name | to pipe from a system command.
Use an optional index enclosed in brackets after a file
name to specify a desired subimage of a multi-resolution
image format like Photo CD (e.g. img0001.pcd[4]) or a
range for MPEG images (e.g. video.mpg[50-75]). A subimage
specification can be disjoint (e.g. image.tiff[2,7,4]).
For raw images, specify a subimage with a geometry (e.g.
-size 640x512 image.rgb[320x256+50+50]).
Single images are read with the filename you specify.
Alternatively, you can display an image sequence with a
single filename. Define the range of the image sequence
with -scene. Each image in the range is read with the
filename followed by a period (.) and the scene number.
You can change this behavior by embedding a printf format
specification in the file name. For example,
-scene 0-9 image%02d.miff
displays files image00.miff, image01.miff, through
image09.miff.
BUTTONS
The effects of each button press is described below.
Three buttons are required. If you have a two button
mouse, button 1 and 3 are returned. Press ALT and button
3 to simulate button 2.
1 Press this button to map or unmap the Command
widget. See the next section for more information
about the Command widget.
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2 Press and drag to define a region of the image to
magnify.
3 Press and drag to choose from a select set of
display(1) commands. This button behaves
differently if the image being displayed is a
visual image directory. Here, choose a particular
tile of the directory and press this button and
drag to select a command from a pop-up menu.
Choose from these menu items:
Open
Next
Former
Delete
Update
If you choose Open, the image represented by the
tile is displayed. To return to the visual image
directory, choose Next from the Command widget
(refer to COMMAND WIDGET). Next and Former moves
to the next or former image respectively. Choose
Delete to delete a particular image tile. Finally,
choose Update to synchronize all the image tiles
with their respective images. See montage(1) and
miff(5) for more details.
COMMAND WIDGET
The Command widget lists a number of sub-menus and
commands. They are
File
Open...
Next
Former
Select...
Save...
Print...
Delete...
Canvas...
Visual Directory...
Quit
Edit
Undo
Redo
Cut
Copy
Paste
View
Half Size
Original Size
Double Size
Resize...
Apply
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Refresh
Restore
Transform
Crop
Chop
Flop
Flip
Rotate Right
Rotate Left
Rotate...
Shear...
Roll...
Trim Edges
Enhance
Hue...
Saturation...
Brightness...
Gamma...
Spiff...
Dull
Equalize
Normalize
Negate
Grayscale
Map...
Quantize...
Effects
Despeckle
Emboss
Reduce Noise
Add Noise
Sharpen...
Blur...
Threshold...
Edge Detect...
Spread...
Shade...
Raise...
Segment...
F/X
Solarize...
Swirl...
Implode...
Wave...
Oil Paint...
Charcoal Draw...
Image Edit
Annotate...
Draw...
Color...
Matte...
Composite...
Add Border...
Add Frame...
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display(1)display(1)
Comment...
Launch...
Region of Interest...
Miscellany
Image Info
Zoom Image
Show Preview...
Show Histogram
Show Matte
Background...
Slide Show
Preferences...
Help
Help
Browse Documentation
About Display
Menu items with a indented triangle have a sub-menu. They
are represented above as the indented items. To access a
sub-menu item, move the pointer to the appropriate menu
and press button 1 and drag. When you find the desired
sub-menu item, release the button and the command is
executed. Move the pointer away from the sub-menu if you
decide not to execute a particular command.
KEYBOARD ACCELERATORS
Accelerators are one or two key presses that effect a
particular command. The keyboard accelerators that
display(1) understands is:
Ctl+O Press to load an image from a file.
Refer to IMAGE LOADING for more details.
space Press to display the next image.
If the image is a multi-paged document such as a
Postscript document, you can skip ahead several
pages by preceeding this command with a number.
For example to display the fourth page beyond the
current page, press 4space.
backspace
Press to display the former image.
If the image is a multi-paged document such as a
Postscript document, you can skip behind several
pages by preceeding this command with a number.
For example to display the fourth page preceeding
the current page, press 4n.
Ctl+S Press to save the image to a file.
Ctl+P Press to print the image to a Postscript printer.
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Ctl+D Press to delete an image file.
Ctl+N Press to create a blank canvas.
Ctl+Q Press to discard all images and exit program.
Ctl+Z Press to undo last image transformation.
Ctl+R Press to redo last image transformation.
Ctl+X Press to cut a region of the image.
Refer to IMAGE CUTTING for more details.
Ctl+C Press to copy a region of the image.
Refer to IMAGE COPYING for more details.
Ctl+V Press to paste a region to the image.
Refer to IMAGE PASTING for more details.
< Press to half the image size.
- Press to return to the original image size.
> Press to double the image size.
% Press to resize the image to a width and height you
specify.
Cmd-A Press to make any image transformations permanent.
By default, any image size transformations are
applied to the original image to create the image
displayed on the X server. However, the
transformations are not permanent (i.e. the
original image does not change size only the X
image does). For example, if you press > the X
image will appear to double in size, but the
original image will in fact remain the same size.
To force the original image to double in size,
press > followed by A.
@ Press to refresh the image window.
C Press to crop the image.
Refer to IMAGE CROPPING for more details.
[ Press to chop the image.
Refer to IMAGE CHOPPING for more details.
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H Press to flop image in the horizontal direction.
V Press to flip image in the vertical direction.
/ Press to rotate the image 90 degrees clockwise.
bs Press to rotate the image 90 degrees counter-
clockwise.
* Press to rotate the image the number of degrees you
specify.
Refer to IMAGE ROTATION for more details.
s Press to shear the image the number of degrees you
specify.
r Press to roll the image.
t Press to trim the image edges.
Shft-H Press to vary the color hue.
Shft-S Press to vary the color saturation.
Shft-L Press to vary the image brightness.
Shft-G Press to gamma correct the image.
Shft-C Press to spiff up the image contrast.
Shft-Z Press to dull the image contrast.
= Press to perform histogram equalization on the
image.
Shft-N Press to perform histogram normalization on the
image.
~ Press to negate the colors of the image.
. Press to convert the image colors to gray.
# Press to set the maximum number of unique colors in
the image.
F2 Press to reduce the speckles in an image.
F3 Press to emboss an image.
F4 Press to eliminate peak noise from an image.
F5 Press to add noise to an image.
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F6 Press to sharpen an image.
F7 Press to blur image an image.
F8 Press to threshold the image.
F9 Press to detect edges within an image.
F10 Press to displace pixels by a random amount.
F11 Press to shade the image using a distant light
source.
F12 Press to lighten or darken image edges to create a
3-D effect.
F13 Press to segment the image by color.
Meta-S Press to swirl image pixels about the center.
Meta-I Press to implode image pixels about the center.
Meta-W Press to alter an image along a sine wave.
Meta-P Press to simulate an oil painting.
Meta-C Press to simulate a charcoal drawing.
Alt-A Press to annotate the image with text.
Refer to IMAGE ANNOTATION for more details.
Alt-D Press to draw a line on the image.
Refer to IMAGE DRAWING for more details.
Alt-P Press to edit an image pixel color.
Refer to COLOR EDITING for more details.
Alt-M Press to edit the image matte information.
Refer to MATTE EDITING for more details.
Alt-V Press to composite the image with another.
Refer to IMAGE COMPOSITING for more details.
Alt-B Press to add a border to the image.
Alt-F Press to add a ornamental frame to the image.
Alt-Shft-!
Press to add an image comment.
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Ctl-A Press to apply an image processing technique to a
region of interest.
Refer to REGION OF INTEREST for more details.
Shft-? Press to display information about the image.
Shft-+ Press to map the zoom image window.
Shft-P Press to preview an image enhancement, effect, or
f/x.
F1 Press to display helpful information about
display(1).
Find Press to browse documentation about ImageMagick.
1-9 Press to change the level of magnification.
Use the arrow keys to move the image one pixel up,
down, left, or right within the magnify window. Be
sure to first map the magnify window by pressing
button 2.
Press ALT and one of the arrow keys to trim off one
pixel from any side of the image.
X RESOURCES
Display options can appear on the command line or in your
X resource file. Options on the command line supersede
values specified in your X resource file. See X(1) for
more information on X resources.
Most display options have a corresponding X resource. In
addition, display uses the following X resources:
background (class Background)
Specifies the preferred color to use for the image
window background. The default is #ccc.
borderColor (class BorderColor)
Specifies the preferred color to use for the image
window border. The default is #ccc.
borderWidth (class BorderWidth)
Specifies the width in pixels of the image window
border. The default is 2.
browseCommand (class browseCommand)
Specifies the name of the preferred browser when
displaying ImageMagick documentation. The default
is netscape %s.
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confirmExit (class ConfirmExit)
Display pops up a dialog box to confirm exiting the
program when exiting the program. Set this
resource to False to exit without a confirmation.
displayGamma (class DisplayGamma)
Specifies the gamma of your X server.
You can apply separate gamma values to the red,
green, and blue channels of the image with a gamma
value list delineated with slashes (i.e.
1.7/2.3/1.2).
The default is 2.2.
displayWarnings (class DisplayWarnings)
Display pops up a dialog box whenever a warning
message occurs. Set this resource to False to
ignore warning messages.
font (class FontList)
Specifies the name of the preferred font to use in
normal formatted text. The default is 14 point
Helvetica.
font[1-9] (class Font[1-9])
Specifies the name of the preferred font to use
when annotating the image window with text. The
default fonts are fixed, variable, 5x8, 6x10,
7x13bold, 8x13bold, 9x15bold, 10x20, and 12x24.
Refer to IMAGE ANNOTATION for more details.
foreground (class Foreground)
Specifies the preferred color to use for text
within the image window. The default is black.
gammaCorrect (class gammaCorrect)
This resource, if true, will lighten or darken an
image of known gamma to match the gamma of the
display (see resource displayGamma). The default
is True.
geometry (class Geometry)
Specifies the preferred size and position of the
image window. It is not necessarily obeyed by all
window managers.
iconGeometry (class IconGeometry)
Specifies the preferred size and position of the
application when iconified. It is not necessarily
obeyed by all window managers.
iconic (class Iconic)
This resource indicates that you would prefer that
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the application's windows initially not be visible
as if the windows had be immediately iconified by
you. Window managers may choose not to honor the
application's request.
magnify (class Magnify)
specifies an integral factor by which the image
should be enlarged. The default is 3.
This value only affects the magnification window
which is invoked with button number 3 after the
image is displayed. Refer to BUTTONS for more
details.
matteColor (class MatteColor)
Specify the color of windows. It is used for the
backgrounds of windows, menus, and notices. A 3D
effect is achieved by using highlight and shadow
colors derived from this color. Default value:
#ccc.
name (class Name)
This resource specifies the name under which
resources for the application should be found.
This resource is useful in shell aliases to
distinguish between invocations of an application,
without resorting to creating links to alter the
executable file name. The default is the
application name.
pen[1-9] (class Pen[1-9])
Specifies the color of the preferred font to use
when annotating the image window with text. The
default colors are black, blue, green, cyan, gray,
red, magenta, yellow, and white. Refer to IMAGE
ANNOTATION for more details.
printCommand (class PrintCommand)
This command is executed whenever Print is issued
(see BUTTONS. In general, it is the command to
print Postscript to your printer. Default value:
lp -c -s %i.
sharedMemory (class SharedMemory)
This resource specifies whether display should
attempt use shared memory for pixmaps. ImageMagick
must be compiled with shared memory support, and
the display must support the MIT-SHM extension.
Otherwise, this resource is ignored. The default
is True.
textFont (class textFont)
Specifies the name of the preferred font to use in
fixed (typewriter style) formatted text. The
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default is 14 point Courier.
title (class Title)
This resource specifies the title to be used for
the image window. This information is sometimes
used by a window manager to provide a header
identifying the window. The default is the image
file name.
undoCache (class UndoCache)
Specifies, in mega-bytes, the amount of memory in
the undo edit cache. Each time you modify the
image it is saved in the undo edit cache as long as
memory is available. You can subsequently undo one
or more of these transformations. The default is
16 mega-bytes.
usePixmap (class UsePixmap)
Images are maintained as a XImage by default. Set
this resource to True to utilize a server Pixmap
instead. This option is useful if your image
exceeds the dimensions of your server screen and
you intend to pan the image. Panning is much
faster with Pixmaps than with a XImage. Pixmaps
are considered a precious resource, use them with
discretion.
To set the geometry of the Magnify or Pan or
window, use the geometry resource. For example, to
set the Pan window geometry to 256x256, use:
display.pan.geometry: 256x256
IMAGE LOADING
To select an image to display, choose Open of the File
sub-menu from the Command widget. A file browser is
displayed. To choose a particular image file, move the
pointer to the filename and press any button. The
filename is copied to the text window. Next, press Open
or press the RETURN key. Alternatively, you can type the
image file name directly into the text window. To descend
directories, choose a directory name and press the button
twice quickly. A scrollbar allows a large list of
filenames to be moved through the viewing area if it
exceeds the size of the list area.
You can trim the list of file names by using shell
globbing characters. For example, type *.jpg to list only
files that end with .jpg.
To select your image from the X server screen instead of
from a file, Choose Grab of the Open widget.
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display(1)display(1)VISUAL IMAGE DIRECTORY
To create a Visual Image Directory, choose Visual
Directory of the File sub-menu from the Command widget. A
file browser is displayed. To create a Visual Image
Directory from all the images in the current directory,
press Directory or press the RETURN key. Alternatively,
you can select a set of image names by using shell
globbing characters. For example, type *.jpg to include
only files that end with .jpg. To descend directories,
choose a directory name and press the button twice
quickly. A scrollbar allows a large list of filenames to
be moved through the viewing area if it exceeds the size
of the list area.
After you select a set of files, they are turned into
thumbnails and tiled onto a single image. Now move the
pointer to a particular thumbnail and press button 3 and
drag. Finally, select Open. The image represented by the
thumbnail is displayed at its full size. Choose Next from
the File sub-menu of the Command widget to return to the
Visual Image Directory.
IMAGE CUTTING
Note that cut information for image window is not retained
for colormapped X server visuals (e.g. StaticColor,
StaticColor, GrayScale, PseudoColor). Correct cutting
behavior may require a TrueColor or DirectColor visual or
a Standard Colormap.
To begin, press choose Cut of the Edit sub-menu from the
Command widget (see COMMAND WIDGET). Alternatively, press
F3 in the image window (see KEYBOARD ACCELERATORS).
A small window appears showing the location of the cursor
in the image window. You are now in cut mode. In cut
mode, the Command widget has these options:
Help
Dismiss
To define a cut region, press button 1 and drag. The cut
region is defined by a highlighted rectangle that expands
or contracts as it follows the pointer. Once you are
satisfied with the cut region, release the button. You
are now in rectify mode. In rectify mode, the Command
widget has these options:
Cut
Help
Dismiss
You can make adjustments by moving the pointer to one of
the cut rectangle corners, pressing a button, and
dragging. Finally, press Cut to commit your copy region.
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To exit without cutting the image, press Dismiss.
IMAGE COPYING
To begin, press choose Copy of the Edit sub-menu from the
Command widget (see COMMAND WIDGET). Alternatively, press
F4 in the image window (see KEYBOARD ACCELERATORS).
A small window appears showing the location of the cursor
in the image window. You are now in copy mode. In copy
mode, the Command widget has these options:
Help
Dismiss
To define a copy region, press button 1 and drag. The
copy region is defined by a highlighted rectangle that
expands or contracts as it follows the pointer. Once you
are satisfied with the copy region, release the button.
You are now in rectify mode. In rectify mode, the Command
widget has these options:
Copy
Help
Dismiss
You can make adjustments by moving the pointer to one of
the copy rectangle corners, pressing a button, and
dragging. Finally, press Copy to commit your copy region.
To exit without copying the image, press Dismiss.
IMAGE PASTING
To begin, press choose Paste of the Edit sub-menu from the
Command widget (see COMMAND WIDGET). Alternatively, press
F5 in the image window (see KEYBOARD ACCELERATORS).
A small window appears showing the location of the cursor
in the image window. You are now in Paste mode. To exit
immediately, press Dismiss. In Paste mode, the Command
widget has these options:
Operators
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Multiply
Bumpmap
Copy
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CopyRed
CopyGreen
CopyBlue
CopyOpacity
Help
Dismiss
Choose a composite operation from the Operators sub-menu
of the Command widget. How each operator behaves is
described below. image window is the image currently
displayed on your X server and image is the image obtained
with the File Browser widget.
Over The result is the union of the two image shapes,
with image obscuring image window in the region of
overlap.
In The result is simply image cut by the shape of
image window. None of the image data of image
window is in the result.
Out The resulting image is image with the shape of
image window cut out.
Atop The result is the same shape as image image window,
with image obscuring image window where the image
shapes overlap. Note this differs from over
because the portion of image outside image window's
shape does not appear in the result.
Xor The result is the image data from both image and
image window that is outside the overlap region.
The overlap region is blank.
Plus The result is just the sum of the image data.
Output values are cropped to 255 (no overflow).
This operation is independent of the matte
channels.
Minus The result of image - image window, with underflow
cropped to zero. The matte channel is ignored (set
to 255, full coverage).
Add The result of image + image window, with overflow
wrapping around (mod 256).
Subtract
The result of image - image window, with underflow
wrapping around (mod 256). The add and subtract
operators can be used to perform reversible
transformations.
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Difference
The result of abs(image - image window). This is
useful for comparing two very similar images.
Multipy
The result of composite image * image. This is
useful for the creation of drop-shadows.
Bumpmap
The result of image window shaded by image.
Copy The resulting image is image window replaced with
image. Here the matte information is ignored.
CopyRed
The resulting image is the red layer of image
window replaced with the red layer of image. The
remaining layers remain untouched.
CopyGreen
The resulting image is the green layer of image
window replaced with the green layer of image. The
remaining layers remain untouched.
CopyBlue
The resulting image is the blue layer of image
window replaced with the blue layer of image. The
remaining layers remain untouched.
CopyOpacity
The resulting image is the matte layer of image
window replaced with the matte layer of image. The
remaining layers remain untouched.
The image compositor requires a matte, or alpha
channel in the image for some operations. This
extra channel usually defines a mask which
represents a sort of a cookie-cutter for the image.
This is the case when matte is 255 (full coverage)
for pixels inside the shape, zero outside, and
between zero and 255 on the boundary. If image
does not have a matte channel, it is initialized
with 0 for any pixel matching in color to pixel
location (0,0), otherwise 255. See MATTE EDITING
for a method of defining a matte channel.
Note that matte information for image window is not
retained for colormapped X server visuals (e.g.
StaticColor, StaticColor, GrayScale, PseudoColor).
Correct compositing behavior may require a
TrueColor or DirectColor visual or a Standard
Colormap.
Choosing a composite operator is optional. The
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default operator is replace. However, you must
choose a location to composite your image and press
button 1. Press and hold the button before
releasing and an outline of the image will appear
to help you identify your location.
The actual colors of the pasted image is saved.
However, the color that appears in image window may
be different. For example, on a monochrome screen
image window will appear black or white even though
your pasted image may have many colors. If the
image is saved to a file it is written with the
correct colors. To assure the correct colors are
saved in the final image, any PseudoClass image is
promoted to DirectClass (see miff(5)). To force a
PseudoClass image to remain PseudoClass, use
-colors.
IMAGE CROPPING
To begin, press choose Crop of the Transform sub-menu from
the Command widget (see COMMAND WIDGET). Alternatively,
press [ in the image window (see KEYBOARD ACCELERATORS).
A small window appears showing the location of the cursor
in the image window. You are now in crop mode. In crop
mode, the Command widget has these options:
Help
Dismiss
To define a cropping region, press button 1 and drag. The
cropping region is defined by a highlighted rectangle that
expands or contracts as it follows the pointer. Once you
are satisfied with the cropping region, release the
button. You are now in rectify mode. In rectify mode,
the Command widget has these options:
Crop
Help
Dismiss
You can make adjustments by moving the pointer to one of
the cropping rectangle corners, pressing a button, and
dragging. Finally, press Crop to commit your cropping
region. To exit without cropping the image, press
Dismiss.
IMAGE CHOPPING
An image is chopped interactively. There is no command
line argument to chop an image. To begin, choose Chop of
the Transform sub-menu from the Command widget (see
COMMAND WIDGET). Alternatively, press ] in the image
window (see KEYBOARD ACCELERATORS).
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You are now in Chop mode. To exit immediately, press
Dismiss. In Chop mode, the Command widget has these
options:
Direction
horizontal
vertical
Help
Dismiss
If the you choose the horizontal direction (this is the
default), the area of the image between the two horizontal
endpoints of the chop line is removed. Otherwise, the
area of the image between the two vertical endpoints of
the chop line is removed.
Select a location within the image window to begin your
chop, press and hold any button. Next, move the pointer
to another location in the image. As you move a line will
connect the initial location and the pointer. When you
release the button, the area within the image to chop is
determined by which direction you choose from the Command
widget.
To cancel the image chopping, move the pointer back to the
starting point of the line and release the button.
IMAGE ROTATION
Press the / key to rotate the image 90 degrees or \ to
rotate -90 degrees (see KEYBOARD ACCELERATORS). To
interactively choose the degree of rotation, choose
Rotate... of the Pixel Transform submenu from the Command
Widget (see COMMAND WIDGET). Alternatively, press * in
the image window (see KEYBOARD ACCELERATORS).
A small horizontal line is drawn next to the pointer. You
are now in rotate mode. To exit immediately, press
Dismiss. In rotate mode, the Command widget has these
options:
Pixel Color
black
blue
cyan
green
gray
red
magenta
yellow
white
Browser...
Direction
horizontal
vertical
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Crop
false
true
Sharpen
false
true
Help
Dismiss
Choose a background color from the Pixel Color sub-menu.
Additional background colors can be specified with the
color browser. You can change the menu colors by setting
the X resources pen1 through pen9. Refer to X RESOURCES
for more details.
If you choose the color browser and press Grab, you can
select the background color by moving the pointer to the
desired color on the screen and press any button. The
transparent color updates the image matte channel and is
useful for image compositing.
Choose a point in the image window and press this button
and hold. Next, move the pointer to another location in
the image. As you move a line connects the initial
location and the pointer. When you release the button,
the degree of image rotation is determined by the slope of
the line you just drew. The slope is relative to the
direction you choose from the Direction sub-menu of the
Command widget.
To cancel the image rotation, move the pointer back to the
starting point of the line and release the button.
IMAGE ANNOTATION
An image is annotated interactively. There is no command
line argument to annotate an image. To begin, choose
Annotate of the Image Edit sub-menu from the Command
widget (see COMMAND WIDGET). Alternatively, press a in
the image window (see KEYBOARD ACCELERATORS).
A small window appears showing the location of the cursor
in the image window. You are now in annotate mode. To
exit immediately, press Dismiss. In annotate mode, the
Command widget has these options:
Font Name
fixed
variable
5x8
6x10
7x13bold
8x13bold
9x15bold
10x20
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12x24
Browser...
Font Color
black
blue
cyan
green
gray
red
magenta
yellow
white
transparent
Browser...
Box Color
black
blue
cyan
green
gray
red
magenta
yellow
white
transparent
Browser...
Rotate Text
-90
-45
-30
0
30
45
90
180
Dialog...
Help
Dismiss
Choose a font name from the Font Name sub-menu.
Additional font names can be specified with the font
browser. You can change the menu names by setting the X
resources font1 through font9. Refer to X RESOURCES for
more details.
Choose a font color from the Font Color sub-menu.
Additional font colors can be specified with the color
browser. You can change the menu colors by setting the X
resources pen1 through pen9. Refer to X RESOURCES for
more details.
If you select the color browser and press Grab, you can
choose the font color by moving the pointer to the desired
color on the screen and press any button.
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If you choose to rotate the text, choose Rotate Text from
the menu and select an angle. Typically you will only
want to rotate one line of text at a time. Depending on
the angle you choose, subsequent lines may end up
overwriting each other.
Choosing a font and its color is optional. The default
font is fixed and the default color is black. However,
you must choose a location to begin entering text and
press button 1. An underscore character will appear at
the location of the pointer. The cursor changes to a
pencil to indicate you are in text mode. To exit
immediately, press Dismiss.
In text mode, any key presses will display the character
at the location of the underscore and advance the
underscore cursor. Enter your text and once completed
press Dismiss to finish your image annotation. To correct
errors press BACK SPACE. To delete an entire line of
text, press DELETE. Any text that exceeds the boundaries
of the image window is automatically continued onto the
next line.
The actual color you request for the font is saved in the
image. However, the color that appears in your image
window may be different. For example, on a monochrome
screen the text will appear black or white even if you
choose the color red as the font color. However, the
image saved to a file with -write is written with red
lettering. To assure the correct color text in the final
image, any PseudoClass image is promoted to DirectClass
(see miff(5)). To force a PseudoClass image to remain
PseudoClass, use -colors.
IMAGE COMPOSITING
An image composite is created interactively. There is no
command line argument to composite an image. To begin,
choose Composite of the Image Edit from the Command widget
(see COMMAND WIDGET). Alternatively, press x in the image
window (see KEYBOARD ACCELERATORS).
First a popup window is displayed requesting you to enter
an image name. Press Composite, Grab or type a file name.
Press Cancel if you choose not to create a composite
image. When you choose Grab, move the pointer to the
desired window and press any button.
If the Composite image does not have any matte
information, you are informed and the file browser is
displayed again. Enter the name of a mask image. The
image is typically grayscale and the same size as the
composite image. If the image is not grayscale, it is
converted to grayscale and the resulting intensities are
used as matte information.
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A small window appears showing the location of the cursor
in the image window. You are now in composite mode. To
exit immediately, press Dismiss. In composite mode, the
Command widget has these options:
Operators
over
in
out
atop
xor
plus
minus
add
subtract
difference
bumpmap
replace
Blend
Displace
Help
Dismiss
Choose a composite operation from the Operators sub-menu
of the Command widget. How each operator behaves is
described below. image window is the image currently
displayed on your X server and image is the image obtained
with the File Browser widget.
over The result is the union of the two image shapes,
with image obscuring image window in the region of
overlap.
in The result is simply image cut by the shape of
image window. None of the image data of image
window is in the result.
out The resulting image is image with the shape of
image window cut out.
atop The result is the same shape as image image window,
with image obscuring image window where the image
shapes overlap. Note this differs from over
because the portion of image outside image window's
shape does not appear in the result.
xor The result is the image data from both image and
image window that is outside the overlap region.
The overlap region is blank.
plus The result is just the sum of the image data.
Output values are cropped to 255 (no overflow).
This operation is independent of the matte
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channels.
minus The result of image - image window, with underflow
cropped to zero. The matte channel is ignored (set
to 255, full coverage).
add The result of image + image window, with overflow
wrapping around (mod 256).
subtract
The result of image - image window, with underflow
wrapping around (mod 256). The add and subtract
operators can be used to perform reversible
transformations.
difference
The result of abs(image - image window). This is
useful for comparing two very similar images.
bumpmap
The result of image window shaded by image.
replace
The resulting image is image window replaced with
image. Here the matte information is ignored.
The image compositor requires a matte, or alpha
channel in the image for some operations. This
extra channel usually defines a mask which
represents a sort of a cookie-cutter for the image.
This is the case when matte is 255 (full coverage)
for pixels inside the shape, zero outside, and
between zero and 255 on the boundary. If image
does not have a matte channel, it is initialized
with 0 for any pixel matching in color to pixel
location (0,0), otherwise 255. See MATTE EDITING
for a method of defining a matte channel.
If you choose blend, the composite operator becomes
over. The image matte channel percent transparency
is initialized to factor. The image window is
initialized to (100-factor). Where factor is the
value you specify in the Dialog widget.
Displace shifts the image pixels as defined by a
displacement map. With this option, image is used
as a displacement map. Black, within the
displacement map, is a maximum positive
displacement. White is a maximum negative
displacement and middle gray is neutral. The
displacement is scaled to determine the pixel
shift. By default, the displacement applies in
both the horizontal and vertical directions.
However, if you specify a mask, image is the
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horizontal X displacement and mask the vertical Y
displacement.
Note that matte information for image window is not
retained for colormapped X server visuals (e.g.
StaticColor, StaticColor, GrayScale, PseudoColor).
Correct compositing behavior may require a
TrueColor or DirectColor visual or a Standard
Colormap.
Choosing a composite operator is optional. The
default operator is replace. However, you must
choose a location to composite your image and press
button 1. Press and hold the button before
releasing and an outline of the image will appear
to help you identify your location.
The actual colors of the composite image is saved.
However, the color that appears in image window may
be different. For example, on a monochrome screen
image window will appear black or white even though
your composited image may have many colors. If the
image is saved to a file it is written with the
correct colors. To assure the correct colors are
saved in the final image, any PseudoClass image is
promoted to DirectClass (see miff(5)). To force a
PseudoClass image to remain PseudoClass, use
-colors.
COLOR EDITING
Changing the the color of a set of pixels is performed
interactively. There is no command line argument to edit
a pixel. To begin, choose Color from the Image Edit
submenu of the Command widget (see COMMAND WIDGET).
Alternatively, press c in the image window (see KEYBOARD
ACCELERATORS).
A small window appears showing the location of the cursor
in the image window. You are now in color edit mode. To
exit immediately, press Dismiss. In color edit mode, the
Command widget has these options:
Method
point
replace
floodfill
filltoborder
reset
Pixel Color
black
blue
cyan
green
gray
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red
magenta
yellow
white
Browser...
Border Color
black
blue
cyan
green
gray
red
magenta
yellow
white
Browser...
Fuzz
0
2
4
8
16
Dialog...
Undo
Help
Dismiss
Choose a color editing method from the Method sub-menu of
the Command widget. The point method recolors any pixel
selected with the pointer unless the button is released.
The replace method recolors any pixel that matches the
color of the pixel you select with a button press.
Floodfill recolors any pixel that matches the color of the
pixel you select with a button press and is a neighbor.
Whereas filltoborder recolors any neighbor pixel that is
not the border color. Finally reset changes the entire
image to the designated color.
Next, choose a pixel color from the Pixel Color sub-menu.
Additional pixel colors can be specified with the color
browser. You can change the menu colors by setting the X
resources pen1 through pen9. Refer to X RESOURCES for
more details.
Now press button 1 to select a pixel within the image
window to change its color. Additional pixels may be
recolored as prescribed by the method you choose.
If the Magnify widget is mapped, it can be helpful in
positioning your pointer within the image (refer to button
2). Alternatively you can select a pixel to recolor from
within the Magnify widget. Move the pointer to the
Magnify widget and position the pixel with the cursor
control keys. Finally, press a button to recolor the
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selected pixel (or pixels).
The actual color you request for the pixels is saved in
the image. However, the color that appears in your image
window may be different. For example, on a monochrome
screen the pixel will appear black or white even if you
choose the color red as the pixel color. However, the
image saved to a file with -write is written with red
pixels. To assure the correct color text in the final
image, any PseudoClass image is promoted to DirectClass
(see miff(5)). To force a PseudoClass image to remain
PseudoClass, use -colors.
MATTE EDITING
Matte information within an image is useful for some
operations such as image compositing (See IMAGE
COMPOSITING). This extra channel usually defines a mask
which represents a sort of a cookie-cutter for the image.
This is the case when matte is 255 (full coverage) for
pixels inside the shape, zero outside, and between zero
and 255 on the boundary.
Setting the matte information in an image is done
interactively. There is no command line argument to edit
a pixel. To begin, and choose Matte of the Image Edit
sub-menu from the Command widget (see COMMAND WIDGET).
Alternatively, press m in the image window (see KEYBOARD
ACCELERATORS).
A small window appears showing the location of the cursor
in the image window. You are now in matte edit mode. To
exit immediately, press Dismiss. In matte edit mode, the
Command widget has these options:
Method
point
replace
floodfill
filltoborder
reset
Border Color
black
blue
cyan
green
gray
red
magenta
yellow
white
Browser...
Fuzz
0
2
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4
8
16
Dialog...
Matte
Undo
Help
Dismiss
Choose a matte editing method from the Method sub-menu of
the Command widget. The point method changes the matte
value of the any pixel selected with the pointer until the
button is released. The replace method changes the matte
value of any pixel that matches the color of the pixel you
select with a button press. Floodfill changes the matte
value of any pixel that matches the color of the pixel you
select with a button press and is a neighbor. Whereas
filltoborder changes the matte value of any neighbor pixel
that is not the border color. Finally reset changes the
entire image to the designated matte value.
Choose Matte Value and a dialog appears requesting a matte
value. Enter a value between 0 and 255. This value is
assigned as the matte value of the selected pixel or
pixels.
Now, press any button to select a pixel within the image
window to change its matte value.
If the Magnify widget is mapped, it can be helpful in
positioning your pointer within the image (refer to button
2). Alternatively you can select a pixel to change the
matte value from within the Magnify widget. Move the
pointer to the Magnify widget and position the pixel with
the cursor control keys. Finally, press a button to
change the matte value of the selected pixel (or pixels).
Matte information is only valid in a DirectClass image.
Therefore, any PseudoClass image is promoted to
DirectClass (see miff(5)). Note that matte information
for PseudoClass is not retained for colormapped X server
visuals (e.g. StaticColor, StaticColor, GrayScale,
PseudoColor) unless you immediately save your image to a
file (refer to Write). Correct matte editing behavior may
require a TrueColor or DirectColor visual or a Standard
Colormap.
IMAGE DRAWING
An image is drawn upon interactively. There is no command
line argument to draw on an image. To begin, choose Draw
of the Image Edit sub-menu from the Command widget (see
COMMAND WIDGET). Alternatively, press d in the image
window (see KEYBOARD ACCELERATORS).
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The cursor changes to a crosshair to indicate you are in
draw mode. To exit immediately, press Dismiss. In draw
mode, the Command widget has these options:
Primitive
point
line
rectangle
fill rectangle
circle
fill circle
ellipse
fill ellipse
polygon
fill polygon
Color
black
blue
cyan
green
gray
red
magenta
yellow
white
transparent
Browser...
Stipple",
Brick",
Diagonal",
Scales",
Vertical",
Wavy",
Translucent",
Opaque",
Open...",
Width
1
2
4
8
16
Dialog...
Undo
Help
Dismiss
Choose a drawing primitive from the Primitive sub-menu.
Next, choose a color from the Color sub-menu. Additional
colors can be specified with the color browser. You can
change the menu colors by setting the X resources pen1
through pen9. Refer to X RESOURCES for more details.
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If you choose the color browser and press Grab, you can
select the primitive color by moving the pointer to the
desired color on the screen and press any button. The
transparent color updates the image matte channel and is
useful for image compositing.,
Choose a stipple, if appropriate, from the Stipple sub-
menu. Additional stipples can be specified with the file
browser. Stipples obtained from the file browser must be
on disk in the X11 bitmap format.
Choose a line width from the Width sub-menu. To choose a
specific width select the Dialog widget.
Choose a point in the image window and press button 1 and
hold. Next, move the pointer to another location in the
image. As you move, a line connects the initial location
and the pointer. When you release the button, the image
is updated with the primitive you just drew. For
polygons, the image is updated when you press and release
the button without moving the pointer.
To cancel image drawing, move the pointer back to the
starting point of the line and release the button.
REGION OF INTEREST
To begin, press choose Region of Interest of the Transform
sub-menu from the Command widget (see COMMAND WIDGET).
Alternatively, press R in the image window (see KEYBOARD
ACCELERATORS).
A small window appears showing the location of the cursor
in the image window. You are now in region of interest
mode. In region of interest mode, the Command widget has
these options:
Help
Dismiss
To define a region of interest, press button 1 and drag.
The region of interest is defined by a highlighted
rectangle that expands or contracts as it follows the
pointer. Once you are satisfied with the region of
interest, release the button. You are now in apply mode.
In apply mode the Command widget has these options:
File
Save...
Print...
Edit
Undo
Redo
Transform
Flip
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Flop
Rotate Right
Rotate Left
Enhance
Hue...
Saturation...
Brightness...
Gamma...
Spiff
Dull
Equalize
Normalize
Negate
Grayscale
Quantize...
Effects
Despeckle
Emboss
Reduce Noise
Add Noise
Sharpen...
Blur...
Threshold...
Edge Detect...
Spread...
Shade...
Raise...
Segment...
F/X
Swirl...
Implode...
Wave...
Oil Paint...
Charcoal Draw...
Miscellany
Image Info
Zoom Image
Show Preview...
Show Histogram
Show Matte
Help
Dismiss
You can make adjustments to the region of interest by
moving the pointer to one of the rectangle corners,
pressing a button, and dragging. Finally, choose an image
processing technique from the Command widget. You can
choose more than one image processing technique to apply
to an area. Alternatively, you can move the region of
interest before applying another image processing
technique. To exit, press Dismiss.
IMAGE PANNING
When an image exceeds the width or height of the X server
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screen, display maps a small panning icon. The rectangle
within the panning icon shows the area that is currently
displayed in the the image window. To pan about the
image, press any button and drag the pointer within the
panning icon. The pan rectangle moves with the pointer
and the image window is updated to reflect the location of
the rectangle within the panning icon. When you have
selected the area of the image you wish to view, release
the button.
Use the arrow keys to pan the image one pixel up, down,
left, or right within the image window.
The panning icon is withdrawn if the image becomes smaller
than the dimensions of the X server screen.
IMAGE SEGMENTATION
Use -segment to segment an image by analyzing the
histograms of the color components and identifying units
that are homogeneous with the fuzzy c-means technique.
The scale-space filter analyzes the histograms of the
three color components of the image and identifies a set
of classes. The extents of each class is used to coarsely
segment the image with thresholding. The color associated
with each class is determined by the mean color of all
pixels within the extents of a particular class. Finally,
any unclassified pixels are assigned to the closest class
with the fuzzy c-means technique.
The fuzzy c-Means algorithm can be summarized as follows:
o Build a histogram, one for each color component
of the image.
o For each histogram, successively apply the scale-
space filter and build an interval tree of zero
crossings in the second derivative at each scale.
Analyze this scale-space ``fingerprint'' to
determine which peaks or valleys in the histogram
are most predominant.
o The fingerprint defines intervals on the axis of
the histogram. Each interval contains either a
minima or a maxima in the original signal. If each
color component lies within the maxima interval,
that pixel is considered ``classified'' and is
assigned an unique class number.
o Any pixel that fails to be classified in the
above thresholding pass is classified using the
fuzzy c-Means technique. It is assigned to one of
the classes discovered in the histogram analysis
phase.
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The fuzzy c-Means technique attempts to cluster a pixel by
finding the local minima of the generalized within group
sum of squared error objective function. A pixel is
assigned to the closest class of which the fuzzy
membership has a maximum value.
For additional information see
Young Won Lim, Sang Uk Lee, "On The Color Image
Segmentation Algorithm Based on the Thresholding
and the Fuzzy c-Means Techniques", Pattern
Recognition, Volume 23, Number 9, pages 935-952,
1990.
USER PREFERENCES
Preferences affect the default behavior of display(1).
The preferences are either true or false and are stored in
your home directory as .displayrc:
display image centered on a backdrop
This backdrop covers the entire workstation screen
and is useful for hiding other X window activity
while viewing the image. The color of the
backdrop is specified as the background color.
Refer to X RESOURCES for details.
confirm on program exit
Ask for a confirmation before exiting the
display(1) program.
correct image for display gamma
If the image has a known gamma, the gamma is
corrected to match that of the X server (see the X
resource displayGamma).
apply Floyd/Steinberg error diffusion to image
The basic strategy of dithering is to trade
intensity resolution for spatial resolution by
averaging the intensities of several neighboring
pixels. Images which suffer from severe contouring
when reducing colors can be improved with this
preference.
use a shared colormap for colormapped X visuals
This option only applies when the default X server
visual is PseudoColor or GrayScale. Refer to
-visual for more details. By default, a shared
colormap is allocated. The image shares colors
with other X clients. Some image colors could be
approximated, therefore your image may look very
different than intended. Choose Private and the
image colors appear exactly as they are defined.
However, other clients may go technicolor when the
image colormap is installed.
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display(1)display(1)display images as an X server pixmap
Images are maintained as a XImage by default. Set
this resource to True to utilize a server Pixmap
instead. This option is useful if your image
exceeds the dimensions of your server screen and
you intend to pan the image. Panning is much
faster with Pixmaps than with a XImage. Pixmaps
are considered a precious resource, use them with
discretion.
ENVIRONMENTdisplay
To get the default host, display number, and
screen.
SEE ALSOanimate(1), import(1), montage(1), mogrify(1), mosaic(1),
convert(1), composite(1)COPYRIGHT
Copyright (C) 2001 ImageMagick Studio, a non-profit
organization dedicated to making software imaging
solutions freely available.
Permission is hereby granted, free of charge, to any
person obtaining a copy of this software and associated
documentation files ("ImageMagick"), to deal in
ImageMagick without restriction, including without
limitation the rights to use, copy, modify, merge,
publish, distribute, sublicense, and/or sell copies of
ImageMagick, and to permit persons to whom the ImageMagick
is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice
shall be included in all copies or substantial portions of
ImageMagick.
The software is provided "as is", without warranty of any
kind, express or implied, including but not limited to the
warranties of merchantability, fitness for a particular
purpose and noninfringement. In no event shall
ImageMagick Studio be liable for any claim, damages or
other liability, whether in an action of contract, tort or
otherwise, arising from, out of or in connection with
ImageMagick or the use or other dealings in ImageMagick.
Except as contained in this notice, the name of the
ImageMagick Studio shall not be used in advertising or
otherwise to promote the sale, use or other dealings in
ImageMagick without prior written authorization from the
ImageMagick Studio.
ImageMagick $Date: 2001/12/04 18:54:24 $ 47
display(1)display(1)ACKNOWLEDGEMENTS
The MIT X Consortium for making network transparent
graphics a reality.
Peder Langlo, Hewlett Packard, Norway, made hundreds of
suggestions and bug reports. Without Peder, ImageMagick
would not be nearly as useful as it is today.
Rod Bogart and John W. Peterson, University of Utah.
Image compositing is loosely based on rlecomp of the Utah
Raster Toolkit.
Michael Halle, Spatial Imaging Group at MIT, for the
initial implementation of Alan Paeth's image rotation
algorithm.
David Pensak, E. I. du Pont de Nemours and Company, for
providing a computing environment that made this program
possible.
Paul Raveling, USC Information Sciences Institute. The
spatial subdivision color reduction algorithm is based on
his Img software.
AUTHORS
John Cristy, ImageMagick Studio
ImageMagick $Date: 2001/12/04 18:54:24 $ 48
