3 ms·
The bottleneck is almost certainly decoding the image (PNGs are zlib compressed, which will be going at something like ~300 MB/s plus the filter stuff PNG does)
by formerly_proven 6y ago
The bottleneck is almost certainly decoding the image (PNGs are zlib compressed, which will be going at something like ~300 MB/s plus the filter stuff PNG does), not comparing raw pixels (which you should be able to do at memory bandwidth, so something in excess of 10 GP/s).
- eps 6y agoCompressed, but not as a single continuous block. The bottleneck will probably be in doing things serially, both with decompression and the disk IO.