plan9fox/sys/man/1/jpg

.TH JPG 1
.SH NAME
jpg, gif, png, tif, ppm, bmp, v210, yuv, ico, tga, tojpg, togeordi, togif, toppm, topng, totif, toico \- view and convert pictures
.SH SYNOPSIS
.B jpg
[
.B -39cdefFkJrtvy
] [
.I file ...
]
.br
.B gif
[
.B -39cdektv
] [
.I file ...
]
.br
.B png
[
.B -39cdektv
] [
.I file ...
]
.br
.B tif
[
.B -39cdektv
] [
.I file ...
]
.br
.B ppm
[
.B -39cdektv
] [
.I file ...
]
.br
.B bmp
[
.B -39cdektv
] [
.I file ...
]
.br
.B v210
[
.B -39cdektv
] [
.I file ...
]
.br
.B tga
[
.B -39cdektv
] [
.I file ...
]
.br
.B yuv
[
.B -39cdektv
] [
.I file ...
]
.PP
.B tojpg
[
.B -c
.I comment
] [
.B -ks
] [
.I file
]
.br
.B togeordi
[
.B -c
.I comment
] [
.B -k
] [
.I file
]
.br
.B togif
[
.B -c
.I comment
] [
.B -l
.I loopcount
] [
.B -d
.I msec
] [
.B -t
.I transindex
] [
.I file ...
[
.B -d
.I msec
]
.I file ...
|
.B -E
]
.br
.B toppm
[
.B -c
.I comment
] [
.B -r
] [
.I file
]
.br
.B topng
[
.B -c
.I comment
] [
.B -g
.I gamma
] [
.I file
]
.br
.B totif
[
.B -c
.I comment
] [
.B -3bgGhklLptvyY
] [
.I file
]
.PP
.B ico
[
.B -c
] [
.I file
]
.br
.B toico
[
.I file ...
]
.SH DESCRIPTION
These programs read, display, and write image files in public formats.
.IR Jpg ,
.IR gif ,
.IR png ,
.IR tif ,
.IR ppm ,
.IR bmp ,
.IR tga ,
.IR v210 ,
and
.IR 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.
.IR Tojpg ,
.IR togif ,
.IR toppm ,
.IR topng ,
and
.I totif
read Plan 9 images files, convert them to JPEG, GIF, PPM,
PNG, or TIFF and write them to standard output.
.PP
The default behavior of
.IR jpg ,
.IR gif ,
.IR png ,
.IR tif ,
.IR ppm ,
.IR bmp ,
.IR tga ,
.IR v210 ,
and
.IR yuv
is to display the
.IR file ,
or standard input if no file is named.
Once a file is displayed, typing a character causes the program to display the next image.
Typing a
.BR q ,
DEL, or control-D exits the program.
For a more user-friendly interface, use
.IR page (1),
which invokes these programs to convert the images to standard format,
displays them, and offers scrolling, panning, and menu-driven navigation among the files.
.PP
These programs share many options:
.TP
.B -e
Disable Floyd-Steinberg error diffusion, which is used 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.
.TP
.B -k
Convert and display the image as a black and white (really grey-scale) image.
.TP
.B -v
Convert the image to an RGBV color-mapped image, even if the
display has true RGB color.
.TP
.B -d
Suppress display of the image; this is set automatically by
any of the following options:
.TP
.B -c
Convert the image to a Plan 9 representation, as defined by
.IR image (6),
and write it to standard output.
.TP
.B -9
Like
.BR -c ,
but produce an uncompressed image.
This saves processing time, particularly when the output is
being piped to another program such as
.IR page (1),
since it avoids compression and decompression.
.TP
.B -t
Convert the image, if it is in color, to a true color RGB image.
.TP
.B -3
Like
.BR -t ,
but force the image to RGB even if it is originally grey-scale.
.PD
.PP
.I Jpg
has two extra options used to process the output of the LML
video card:
.TP
.B -f
Merge two adjacent images, which represent the two fields of a video picture,
into a single image.
.TP
.B -F
The input is a motion JPEG file, with multiple images representing frames of the movie.  Sets
.BR -f .
.PD
.PP
The
.IR tojpg ,
.IR togif ,
.IR toppm
and
.IR 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
.B -c
to set the comment field of the resulting file.
The
.B -r
option makes
.I toppm
output raw PPM.
The default is to output plain PPM.
The
.B -k
option makes
.I tojpg
output grey-scale images,
and the
.B -s
option makes it output scratched JPEG images.
.I Togeordi
is an
.IR rc (1)
script that invokes
.B tojpg
.BR -s .
.I Totif
accepts many options.
Choosing Huffman, T4, or T6 compression
forces the image to GREY1.
.TP
.B -3
Convert the image to a true color RGB image.
.TP
.B -b
Convert the image to a GREY1 black and white image.
.TP
.B -g
Use T4 one-dimensional compression.
.TP
.B -G
Use T4 two-dimensional compression.
.TP
.B -h
Use Huffman compression.
.TP
.B -k
Convert the image to a GREY8 grey-scale image.
.TP
.B -l
Use LZW compression.
.TP
.B -L
Use LZW compression with horizontal differencing.
Some TIFF decoders may not support horizontal
differencing applied to images of depths less than eight.
.TP
.B -p
Use Packbits compression.
.TP
.B -t
Use T6 compression.
.TP
.B -v
Convert the image to an RGBV color-mapped image.
.TP
.B -y
Convert the image to a GREY2 grey-scale image.
.I Totif
will then convert it to GREY4 before encoding
because TIFF does not support depths of two.
.TP
.B -Y
Convert the image to a GREY4 grey-scale image.
.PP
If there is only one input picture,
.I togif
converts the image to GIF format.
If there are many
.IR files ,
though, it will assemble them into an animated GIF file.
The options control this process:
.TP
.BI -l loopcount
By default, the animation will loop forever;
.I 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.
.TP
.BI -d msec
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
.IR file .
.TP
.B -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.
.PP
.I Gif
translates files that contain a `transparency' index by attaching
an alpha channel to the converted image.
.PP
.I Ico
displays or converts a Windows icon (.ico) file.  If no file is
specified,
.I ico
reads from standard input.
Icon files
contain sets of icons represented by an image and a mask. The
.B -c
option causes
.I 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 (\fIwidth\fBx\fIheight\fB.image\fR),
write any icon's mask as a Plan 9 image (\fIwidth\fBx\fIheight\fB.mask\fR),
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.
.PP
.I 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.
.SH SOURCE
.B /sys/src/cmd/jpg
.br
.B /rc/bin/togeordi
.SH "SEE ALSO"
.IR page (1),
.IR image (6).
.br
.B http://www.w3.org/Graphics/JPEG/jfif3.pdf
.br
.B http://www.w3.org/Graphics/JPEG/itu-t81.pdf
.br
.B http://en.wikibooks.org/wiki/JPEG_-_Idea_and_Practice
.br
.B http://en.wikipedia.org/wiki/JPEG
.br
.B http://www.w3.org/Graphics/GIF/spec-gif89a.txt
.br
.B http://www.w3.org/TR/2003/REC-PNG-20031110
.br
.B http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf
.br
.B http://netpbm.sourceforge.net/doc/ppm.html
.br
.B http://en.wikipedia.org/wiki/Windows_bitmap
.br
.B http://en.wikipedia.org/wiki/Yuv
.SH BUGS
Writing an animated GIF using
.I togif
is a clumsy undertaking.
.SH HISTORY
.I Tojpg
first appeared in 9front (May, 2013).
.I Tif
and
.I totif
first appeared in 9front (July, 2013).