-G Output greyscale instead of color
output Name for new PPM file. (use out=- for stdout)
This program converts a GRASS raster file to a PPM image file at the pixel resolution of the CURRENTLY DEFINED REGION. e.g., to get the resolution of the raster map, do:
before running r.out.ppm.
The PPM file created is 24bit color, rawbits storage by default. Using -G, you may force r.out.ppm to use 8bit greyscale instead. The greyscale conversion uses the NTSC conversion:
Y = .30*Red + .59*Green + .11*Blue
One pixel is written for each cell value, so if ew_res and ns_res differ, the aspect ratio of the resulting image will be off.
Last changed: $Date: 2002/01/25 05:45:34 $