path: root/man/man1/jpg.1

.TH JPG 1
.SH NAME
jpg, gif, png, ppm, bmp, yuv, ico, togif, toppm, topng, toico \- view and convert pictures
.SH SYNOPSIS
.B jpg
[
.B -39cdefFkJrtv
] [
.I file ...
]
.br
.B gif
[
.B -39cdektv
] [
.I file ...
]
.br
.B png
[
.B -39cdektv
] [
.I file ...
]
.br
.B ppm
[
.B -39cdektv
] [
.I file ...
]
.br
.B bmp
[
.I file
]
.br
.B yuv
[
.I file
]
.PP
.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 ...
]
.br
.B toppm
[
.B -c
.I comment
] [
.I file
]
.br
.B topng
[
.B -c
.I comment
] [
[
.B -g
.I gamma
] [
.I file
]
.PP
.B ico
[
.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 ppm ,
.IR bmp ,
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 Togif ,
.IR Toppm ,
and
.I topng
read Plan 9 images files, convert them to GIF, PPM, or PNG, and write them to standard output.
.PP
The default behavior of
.IR jpg ,
.IR gif ,
and
.IR ppm
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
.MR 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
.MR image (7) ,
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
.MR 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 togif
and
.IR toppm
programs go the other way: they convert from Plan 9 images to GIF and PPM,
and have no display capability.
Both accept an option
.B -c
to set the comment field of the resulting file.
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 .
.PP
.I Gif
translates files that contain a `transparency' index by attaching
an alpha channel to the converted image.
.PP
.I Ico
displays a Windows icon (.ico) file.  If no file is
specified,
.I ico
reads from standard input.
Icon files
contain sets of icons represeted by an image and a mask.
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),
write any icon's mask as a Plan 9 image (\fIwidth\fBx\fIheight\fB.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.
.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 \*9/src/cmd/jpg
.SH "SEE ALSO"
.MR page (1) ,
.MR image (7) .
.SH BUGS
Writing an animated GIF using
.I togif
is a clumsy undertaking.