On Sun, 2008-10-05 at 00:29 +0200, fremobit wrote:
> In my opinion the needed memory for an image of the dimensions 15000px
> to 15000px at 8bit depth is 214,57MB but Gimp allocates 1,1 GB.
GIMP is not an image viewer, it is an image editor. As such it needs to
allocate not only the memory to hold the image data. It also needs to
hold the image's selection mask and the image projection plus a number
of scaled down versions of that projection. The latter are needed for
accurate and efficient display of the zoomed out image. Depending on the
image type, this easily sums up to more then 10 bytes per pixel for a
For a grayscale image, as in your example, the factor is about 4.666 (1
byte layer data, 1 byte selection mask, 2 bytes for the grayscale-alpha
projection multiplied by 1.333 to account for the tile pyramid).
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