GETX11(1)GETX11(1)NAMEgetx11 - get RLE images to an X11 display
SYNOPSISgetx11 [ -= 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 bright‐
ness 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-pro‐
cessed 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 num‐
ber 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
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 dis‐
play_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 generat‐
ing 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 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 staticgray(0),grayscale(1), pseudocolor(2),static‐
color(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, ...
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 begin‐
ning.
All continuing movie action can be halted by pressing a key or mouse
button.
SEE ALSOurt(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, mag‐
nification, 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.
4th Berkeley Distribution Jan 28, 1990 GETX11(1)
