Regarding the comments about complexity of existing formats - I agree, with the exception of PNG. In terms of complexity, QOI is very similar to PNG filtering phases, i.e. when you strip primary compression phase (Huffman coding) from PNG.
Also, I admire how the author combined a lot of common and cool tricks into QOI:
- Block tags form a sort of a prefix code, making it easy to differentiate block types with differing sizes
- Look-back array is used (common trick from LZW family)
- Delta-coding is used when storing pixel diffs
- In the end, if nothing else works, full pixel value is written
Also, the fact that everything is byte aligned is very appreciated.
This is a breath of fresh air and really impressive how good performance (both processing and size reduction) this gets with so little (very readable!) C.
Regarding the comments about complexity of existing formats - I agree, with the exception of PNG. In terms of complexity, QOI is very similar to PNG filtering phases, i.e. when you strip primary compression phase (Huffman coding) from PNG.
Also, I admire how the author combined a lot of common and cool tricks into QOI:
- Block tags form a sort of a prefix code, making it easy to differentiate block types with differing sizes
- Look-back array is used (common trick from LZW family)
- Delta-coding is used when storing pixel diffs
- In the end, if nothing else works, full pixel value is written
Also, the fact that everything is byte aligned is very appreciated.
This is a breath of fresh air and really impressive how good performance (both processing and size reduction) this gets with so little (very readable!) C.