I am trying to understand the siox-tool code. While looking at the code, I
discovered the following:
static inline void threshold_mask (TileManager *mask, gint x, gint y, gint
width, gint height)
gint row, col;
pixel_region_init (®ion, mask, x, y, width, height, TRUE);
for (pr = pixel_regions_register (1, ®ion);
pr != NULL; pr = pixel_regions_process (pr))
Iterate over all pixels in the region and do something...
Can someone explain to me why the code iterates over all pixels in a region
and then over all regions and not just over all pixels in a layer? What are
PixelRegions actually, what are they used for and why they are needed here?
(I had a look at http://developer.gimp.org/api/2.0/app/app-pixel-region.html
but this doesn't explain what they are for)
Thank you very much in advance,
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