save an image from the framebuffer in a
x1 x2 y1 y2
saves all or part of the framebuffer in a file using the
Tag Image File Format, Revision 6.0.
By default, the image is saved with data samples packed (PlanarConfiguration=1),
compressed with the Lempel-Ziv & Welch algorithm (Compression=5),
and with each strip no more than 8 kilobytes.
These characteristics can be overridden, or explicitly specified
with the options described below.
Save the image as a greyscale image
as if it were processed by
This option is included for compatibility with the standard
Specify the compression to use for data written to the output file:
for no compression,
for PackBits compression,
for baseline JPEG compression,
for Deflate compression,
for Lempel-Ziv & Welch compression (default).
compression can be specified together with a
A predictor value of 2 causes
each scanline of the output image to undergo horizontal
differencing before it is encoded; a value
of 1 forces each scanline to be encoded without differencing.
LZW-specific options are specified by appending a ``:''-separated
list to the ``lzw'' option; e.g.
compression with horizontal differencing.
Specify the planar configuration to use in writing image data.
will create a new file with the data samples packed contiguously.
will force data to be written with multi-sample data packed
will force samples to be written in separate planes.
Specify the number of rows (scanlines) in each strip of data
written to the output file.
attempts to set the rows/strip
that no more than 8 kilobytes of data appear in a strip.
Except for the use of
this program is equivalent to the standard
This means, for example, that you can use it in conjunction with
program simply by creating a link called
or by creating a shell script called
with the appropriate options.
If data are saved compressed and in separate planes, then the
rows in each strip is silently set to one to avoid limitations