JPG(1) JPG(1)
NAME
jpg, gif, png, tif, ppm, bmp, v210, yuv, ico, tga, tojpg,
togeordi, togif, toppm, topng, totif, toico - view and
convert pictures
SYNOPSIS
jpg [ -39cdefFkJrtvy ] [ file ... ]
gif [ -39cdektv ] [ file ... ]
png [ -39cdektv ] [ file ... ]
tif [ -39cdektv ] [ file ... ]
ppm [ -39cdektv ] [ file ... ]
bmp [ -39cdektv ] [ file ... ]
v210 [ -39cdektv ] [ file ... ]
tga [ -39cdektv ] [ file ... ]
yuv [ -39cdektv ] [ file ... ]
tojpg [ -c comment ] [ -ks ] [ file ]
togeordi [ -c comment ] [ -k ] [ file ]
togif [ -c comment ] [ -l loopcount ] [ -d msec ] [ -t
transindex ] [ file ... [ -d msec ] file ... | -E ]
toppm [ -c comment ] [ -r ] [ file ]
topng [ -c comment ] [ -g gamma ] [ file ]
totif [ -c comment ] [ -3bgGhklLptvyY ] [ file ]
ico [ -c ] [ file ]
toico [ file ... ]
DESCRIPTION
These programs read, display, and write image files in pub-
lic formats. Jpg, gif, png, tif, ppm, bmp, tga, v210, and
yuv read files in the corresponding formats and, by default,
display them in the current window; options cause them
instead to convert the images to Plan 9 image format and
write them to standard output. Tojpg, togif, toppm, topng,
and totif read Plan 9 images files, convert them to JPEG,
GIF, PPM, PNG, or TIFF and write them to standard output.
The default behavior of jpg, gif, png, tif, ppm, bmp, tga,
v210, and yuv is to display the file, or standard input if
no file is named. Once a file is displayed, typing a char-
acter causes the program to display the next image. Typing
a q, DEL, or control-D exits the program. For a more user-
friendly interface, use page(1), which invokes these pro-
grams to convert the images to standard format, displays
them, and offers scrolling, panning, and menu-driven naviga-
tion among the files.
These programs share many options:
-e Disable Floyd-Steinberg error diffusion, which is used
Page 1 Plan 9 (printed 11/21/24)
JPG(1) JPG(1)
to improve the appearance of images on color-mapped
displays, typically with 8 bits per pixel. Primarily
useful for debugging; if the display has true RGB
color, the image will be displayed in full glory.
-k Convert and display the image as a black and white
(really grey-scale) image.
-v Convert the image to an RGBV color-mapped image, even
if the display has true RGB color.
-d Suppress display of the image; this is set automati-
cally by any of the following options:
-c Convert the image to a Plan 9 representation, as
defined by image(6), and write it to standard output.
-9 Like -c, but produce an uncompressed image. This saves
processing time, particularly when the output is being
piped to another program such as page(1), since it
avoids compression and decompression.
-t Convert the image, if it is in color, to a true color
RGB image.
-3 Like -t, but force the image to RGB even if it is orig-
inally grey-scale.
Jpg has two extra options used to process the output of the
LML video card:
-f Merge two adjacent images, which represent the two
fields of a video picture, into a single image.
-F The input is a motion JPEG file, with multiple images
representing frames of the movie. Sets -f.
The tojpg, togif, toppm and topng programs go the other way:
they convert from Plan 9 images to JPEG, GIF, PPM, PNG, and
TIFF and have no display capability. They all accept an
option -c to set the comment field of the resulting file.
The -r option makes toppm output raw PPM. The default is to
output plain PPM. The -k option makes tojpg output grey-
scale images, and the -s option makes it output scratched
JPEG images. Togeordi is an rc(1) script that invokes tojpg
-s. Totif accepts many options. Choosing Huffman, T4, or
T6 compression forces the image to GREY1.
-3 Convert the image to a true color RGB image.
-b Convert the image to a GREY1 black and white image.
Page 2 Plan 9 (printed 11/21/24)
JPG(1) JPG(1)
-g Use T4 one-dimensional compression.
-G Use T4 two-dimensional compression.
-h Use Huffman compression.
-k Convert the image to a GREY8 grey-scale image.
-l Use LZW compression.
-L Use LZW compression with horizontal differencing. Some
TIFF decoders may not support horizontal differencing
applied to images of depths less than eight.
-p Use Packbits compression.
-t Use T6 compression.
-v Convert the image to an RGBV color-mapped image.
-y Convert the image to a GREY2 grey-scale image. Totif
will then convert it to GREY4 before encoding because
TIFF does not support depths of two.
-Y Convert the image to a GREY4 grey-scale image.
If there is only one input picture, togif converts the image
to GIF format. If there are many files, though, it will
assemble them into an animated GIF file. The options con-
trol this process:
-lloopcount
By default, the animation will loop forever; loopcount
specifies how many times to loop. A value of zero
means loop forever and a negative value means to stop
after playing the sequence once.
-dmsec
By default, the images are displayed as fast as they
can be rendered. This option specifies the time, in
milliseconds, to pause while displaying the next named
file.
-E Specifying this option instead of a list of files will
read the frames from a pipe on fd 0. Each frame is
terminated with EOF. End of the animation is specified
by an extra EOF.
Gif translates files that contain a `transparency' index by
attaching an alpha channel to the converted image.
Ico displays or converts a Windows icon (.ico) file. If no
Page 3 Plan 9 (printed 11/21/24)
JPG(1) JPG(1)
file is specified, ico reads from standard input. Icon
files contain sets of icons represented by an image and a
mask. The -c option causes ico to convert the first icon in
the set and write it to standard output in compressed Plan 9
image format. Otherwise, the whole icon set is displayed.
Clicking the right button pops up a menu that lets you write
any icon's image as a Plan 9 image (widthxheight.image),
write any icon's mask as a Plan 9 image (widthxheight.mask),
or exit. Selecting one of the write menu items yields a
sight cursor. Move the sight over the icon and right click
again to write.
Toico takes a list of Plan 9 image files (or standard input)
and creates a single icon file. The masks in the icon file
will be the white space in the image. The icon file is
written to standard output.
SOURCE
/sys/src/cmd/jpg
/rc/bin/togeordi
SEE ALSO
page(1), image(6).
http://www.w3.org/Graphics/JPEG/jfif3.pdf
http://www.w3.org/Graphics/JPEG/itu-t81.pdf
http://en.wikibooks.org/wiki/JPEG_-_Idea_and_Practice
http://en.wikipedia.org/wiki/JPEG
http://www.w3.org/Graphics/GIF/spec-gif89a.txt
http://www.w3.org/TR/2003/REC-PNG-20031110
http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf
http://netpbm.sourceforge.net/doc/ppm.html
http://en.wikipedia.org/wiki/Windows_bitmap
http://en.wikipedia.org/wiki/Yuv
BUGS
Writing an animated GIF using togif is a clumsy undertaking.
HISTORY
Tojpg first appeared in 9front (May, 2013). Tif and totif
first appeared in 9front (July, 2013).
Page 4 Plan 9 (printed 11/21/24)