This page is documentation to the various fundamental size limits in the Pillow implementation.
- Image sizes cannot be negative. These are checked both in
- Image sizes may be 0. (Although not in 3.4)
- Maximum pixel dimensions are limited to INT32, or 2^31 by the sizes in the image header.
- Individual allocations are limited to 2GB in
- The 2GB allocation puts an upper limit to the xsize of the image of either 2^31 for ‘L’ or 2^29 for ‘RGB’
- Individual memory mapped segments are limited to 2GB in map.c based
on the overflow checks. This requires that any memory mapped image
is smaller than 2GB, as calculated by
y*stride(so 2Gpx for ‘L’ images, and .5Gpx for ‘RGB’
- Any call to internal python size functions for buffers or strings are currently returned as int32, not py_ssize_t. This limits the maximum buffer to 2GB for operations like frombytes and frombuffer.
- This also limits the size of buffers converted using a decoder. (decode.c:127)