pgmramp

Generate a greyscale map. More information: https://netpbm.sourceforge.net/doc/pgmramp.html.

• Generate a left-to-right greyscale map:

pgmtexture -lr > {{path/to/output.pgm}}

• Generate a top-to-bottom greyscale map:

pgmtexture -tb > {{path/to/output.pgm}}

• Generate a rectangular greyscale map:

pgmtexture -rectangle > {{path/to/output.pgm}}

• Generate a elliptical greyscale map:

pgmtexture -ellipse {{path/to/image.pgm}} > {{path/to/output.pgm}}

• Generate a greyscale map from the top-left corner to the bottom-right corner:

pgmtexture -diagonal {{path/to/image.pgm}} > {{path/to/output.pgm}}