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.TH JPG 1

.SH NAME

jpg, gif, png, ppm, bmp, v210, 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 v210

[

.B -39cdektv

] [

.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 ,

.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 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

.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 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 represented 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\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

.SH "SEE ALSO"

.IR page (1),

.IR image (6).

.br

.B http://www.w3.org/Graphics/JPEG/itu-t81.pdf

.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://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.