Next: RGMAP /ABSOLUTE
The program normally allocates less that 1/5 of the total number of
pixels in the map to store the contour segments, and warns the user when
that limit is reached. Besides, contouring may be slow on large maps.
The modifier "Fast" cuts the map in smaller "chunks" and performs con-
touring on those submaps, without the 1/5 above limitation.
The Contour-filling mode (/GREY) can consume (temporary) a large amount
of memory, so is always performed on subsets of the image ("chunks")
when the image size is greater than a system-dependent limit (256*256 on
UNIX systems). When the contours are too involved, an internal limit can
nevertheless be reached. One can then retry the contour-filling by spec-
ifying a smaller "Chunksize" (in pixels). For example, to force contour-
filling on subsets of 64 "lines" of a 512x512 pixel image, type
RGMAP 64*512 /GREY