GETX11(1) 1 (Jan 28, 1990) GETX11(1)
NAME
getx11 - get RLE images to an X11 display
SYNOPSIS
getx11 [ -= window_geometry ] [ -a ] [ -d display ] [ -D ] [
-f ] [ -g display_gamma ] [ -{iI} image_gamma ] [ -j ]
[ -m [ maxframes/sec ] ] [ -n levels ] [ -s ] [ -t
title ] [ -v ] [ -{wW} ] [ -x visualtype ] [ infile ...
]
DESCRIPTION
This program displays an RLE(5) file on an X11 display. It
uses a dithering technique to take a full-color or gray
scale image into the limited number of colors typically
available under X. Its default behavior is to try to
display the image in color with as many brightness levels as
possible (except on a one bit deep display). Several getx11
processes running simultaneously with the same color
resolution will share color map entries.
Getx11 uses the standard X window creation procedure to
create a window with a location and size specified by the
user, with the restriction that the window must be at least
as large as the input image. If the window is turned into
an icon, a smaller version of the image will be displayed in
the icon.
If the input image has only a single channel, and has a
color map, then this color map will be loaded directly (if
possible) instead of using the normal dithering process.
Many images will look better if pre-processed by mcut(1) or
rlequant(1), both of which produce images reduced to a
single channel with a colormap. This is because the colors
that are used to display the image are chosen to be a good
set of colors for that particular image, rather than a set
of colors that are mediocre for all images. The color map
so created will not be shared with other windows. The
picture comment colormap_length specifies the exact number
of useful entries in the input color map. If this is
significantly less than 256, this can save space in the
shared X color map.
OPTIONS
-= window_geometry
Specify the geometry of the window in which the image
will be displayed. This is useful mostly for giving
the location of the window, as the size of the window
will be at least as large as the size of the image.
-a "As is", suppress dithering.
-d display
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GETX11(1) 1 (Jan 28, 1990) GETX11(1)
Give the name of the X display to display the image on.
Defaults to the value of the environment variable
DISPLAY.
-D "Debug mode". The operations in the input RLE(5) file
will be printed as they are read.
-f "No fork." Normally, getx11 will fork itself after
putting the image on the screen, so that the parent
process may return the shell, leaving an "invisible"
child to keep the image refreshed. If -f is specified,
getx11 will not exit to the shell until the image is
removed.
-g display_gamma
Specify the gamma of the X display monitor. The
default value is 2.5, suitable for most color TV
monitors (this is the gamma value assumed by the NTSC
video standard).
-i image_gamma
Specify the gamma (contrast) of the image. A low
contrast image, suited for direct display without
compensation on a high contrast monitor (as most
monitors are) will have a gamma of less than one. The
default image gamma is 1.0. Image gamma may also be
specified by a picture comment in the RLE (5) file of
the form image_gamma=gamma. The command line argument
will override the value in the file if specified. The
dithering process assumes that the incoming image has a
gamma of 1.0 (i.e., a 200 in the input represents an
intensity twice that of a 100.) If this is not the
case, the input values must be adjusted before
dithering.
-I image_gamma
An alternate method of specifying the image gamma, the
number following -I is the gamma of the display for
which the image was originally computed (and is
therefore 1.0 divided by the actual gamma of the
image). Image display gamma may also be specified by a
picture comment in the RLE (5) file of the form
display_gamma=gamma. The command line argument will
override the value in the file if specified.
-j "Jump mode". When reading an image from the standard
input, each scan line is normally displayed as soon as
it is read. This allows a user to monitor the progress
of an image generating program, for example (common
usage is "tail -f image.rle | getx11"). Images read
directly from files are only updated after every 10
lines are read to improve the display speed. This
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GETX11(1) 1 (Jan 28, 1990) GETX11(1)
behavior can be forced for the standard input by
specifying jump mode.
-m [ maxframes/sec ]
"Movie mode." Optional argument is maximum rate at
which movies will play, in frames per second.
-n levels
Specify the number of gray or color levels to be used
in the dithering process. If not this many levels are
available, getx11 will try successively fewer levels
until it is able to allocate enough color map entries.
-s "Stingy mode". Normally, getx11 allocates an X server
pixmap for each image to speed up the window refresh.
If many images are displayed, the server may run out of
memory to store these pixmaps (or its virtual memory
size may get very large). Stingy mode suppresses
pixmap allocation (except in movie mode, where the
pixmaps are necessary for reasonable performance).
-t title
The window name for an image window normally comes from
the input file name or a image_title=title comment in
the RLE file. The window name can be forced to a
particular string with this option.
-v Verbose. (But less so than with -D.)
-w This flag forces getx11 to produce a gray scale
(black-and-white) dithered image instead of a color
image. Color input will be transformed to black and
white via the NTSC Y transform. On a low color
resolution display (a display with only 4 bits, for
example), this will produce a much smoother looking
image than color dithering. It may be used in
conjunction with -n to produce an image with a
specified number of gray levels.
-W This flag forces getx11 to display the image as a
bitonal black and white bitmap image. This is the only
mode available on monochrome (non gray scale) displays
(and is the default there). Black pixels will be
displayed using the BlackPixel(3X) value and white with
the WhitePixel(3X) value (note that these may not be
black and white on certain displays, or when they have
been modified by the user.)
-x visual_type
Specify X visual type to be used. The value may be a
string or a number. This number is assumed to be an
integer between 0 and 5, denoting
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GETX11(1) 1 (Jan 28, 1990) GETX11(1)staticgray(0),grayscale(1),
pseudocolor(2),staticcolor(3), truecolor(4), or
directcolor(5). The string must match one of these
visual types (any capitalization is ignored).
infile ...
Name(s) of the RLE(5)file(s) to display. If not
specified, the image will be read from the standard
input. In movie mode, you get one window, and zooming
is disabled. In normal mode, you get one window per
image.
Mouse/key actions (normal mode)
Mouse 1 (left): Increase zoom factor by 1, center on
this pixel.
Mouse 2 (middle): Recenter on this pixel.
Mouse 3 (right): Decrease zoom factor by 1, center on
this pixel.
Shift mouse 1: Show value at this pixel. In B&W, just
shows intensity.
Shift mouse 2: Toggle between zoomed and unzoomed.
q,Q,^C: Quit.
1,2,3,4,5,6,7,8,9: Set zoom factor.
Arrow keys: Move image (when zoomed). Shifted moves
faster.
Mouse/key actions (movie mode)
Mouse 1: Run movie forward.
Shift Mouse 1: Run movie continuously in current
direction.
Mouse 2: Step movie one frame in current
direction.
Shift Mouse 2: Set movie speed by moving mouse "up" and
"down". The speed chosen is displayed
in the upper right corner of the window.
Mouse 3: Run movie backward.
space: Flip one frame in current direction.
b: "Bounce" image - run it continuously
forwards, then backwards, then forwards,
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GETX11(1) 1 (Jan 28, 1990) GETX11(1)
...
c,C: Run move continuously. "c" runs it
forward, "C" runs it backward. When the
movie reaches the "end", it will
immediately restart from the beginning.
All continuing movie action can be halted by pressing a key
or mouse button.
SEE ALSO
urt(1), RLE(5).
AUTHOR
Spencer W. Thomas, University of Utah (X10 version)
Andrew F. Vesper, Digital Equipment Corp. (X11
modifications)
Martin R. Friedmann, University of Michigan (better X11,
flipbook, magnification, info)
BUGS
Display to a 24-bit visual is somewhat optimized, but could
be faster.
Doesn't pay any attention to the X resource database (i.e.,
cannot be customized via the .Xdefaults file). The options,
while standard for the raster toolkit, are non-standard for
X.
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