Gri Extras

1: Introduction
2: Simple example
3: Fancy example
4: Running Gri
5: Programming Gri
6: General Issues
7: X-Y Plots
8: Contour Plots
9: Image Plots
10: Examples
11: Handling Data
12: Gri Commands
13: Gri Extras
14: Evolution of Gri
15: Installing Gri
16: Gri Bugs
17: System Tools
18: Acknowledgments
19: License
20: Newsgroup

21: Concept Index

13.8: Image extractor

When Gri draws an image with `draw image', it embeds special comments in the PostScript to allow removal of the data by an extractor program; for details see Image PostScript Output. The extractor program is included along with the source distribution, in the C file called `gri_extract_image.c'. After compiling it manually (since there is no Makefile for it), use it as a filter, e.g.
gri_extract_image < file.ps > file.pgm

The result is an image in the pgm format. ("pgm" stands for portable graymap; see unix manpage on `pgm'.) Standard converters are available to convert pgm into most other formats.

Note that just the image is output, not the axes or any other part of your drawing. If you want to make your entire page into an image (perhaps for incorporation into a web-page), try using the FSF `gs' program. For example, if the PostScript filename is `foo.ps', do this:
$ gs foo.ps
GS> (pstoppm.ps)run
GS> (foo) ppm1run
GS> quit