im_tile_cache - cache an image, tilewise
im_tile_cache( IMAGE *in, IMAGE *out,
int tile_width, int tile_height, int max_tiles );
tile_cache(3) behaves rather like im_copy(3) between images in and out,
except that it keeps a cache of computed pixels. This cache is made of
up to max_tiles tiles (a value of -1 for max means any number of
tiles), and each tile is of size tile_width by tile_height pixels. Each
cache tile is made with a single call to im_prepare(3).
This is a lower-level operation than im_cache(3) since it does no
subdivision. It is suitable for caching the output of operations like
im_exr2vips(3) on tiled images.
The function returns 0 on success, and non-zero on error, setting
J Cupitt, 2006
19 May 2006