Seqoia is a derivative of QOI. It can read and write QOI files in addition to SQOA files. SQOA images are about 0.7% smaller than QOI and they are amenable to further reduction using a generic compression tool.
Compared to stb_image and stb_image_write Seqoia offers 20x-50x faster encoding, 3x-4x faster decoding and 20% better compression. It's also stupidly simple and fits in about 400 lines of C.
- sqoaconv.c converts between png <> sqoa <> qoi > jpg
- sqoabench.c a simple wrapper to benchmark stbi, libpng, qoi and sqoa
The recommended MIME type for SQOA images is image/sqoa.
The recommended file extension for SQOA images is .sqoa
Tested on Apple MacBook Air M1
Compiler command:
clang -o sqoabench -I/opt/homebrew/include -L/opt/homebrew/lib -lpng -std=gnu99 -O3 sqoabench.c
Benchmark command:
./sqoabench 10 ../qoi/images --onlytotals
Results:
Seqoia compresses better than QOI on synthetic images like icons.
Total size of PNG files in the "images" folder:
1144723797
Total size of SQOA files before compression:
1342694532
Command:
gzip -r sqoaimages
Total size of SQOA files after compression:
1060163477
The results are smaller than the original PNG folder, all while using a fraction of the power/time to generate them!
For comparison, the total size of STBI-generated PNG files is 1637952729 (STBI is much slower).
The SQOA file format allows for huge images with up to 18 exa-pixels. A streaming en-/decoder can handle these with minimal RAM requirements, assuming there is enough storage space.
This particular implementation of Seqoia however is limited to images with a maximum size of 400 million pixels. It will safely refuse to en-/decode anything larger than that. This is not a streaming en-/decoder. It loads the whole image file into RAM before doing any work and is not extensively optimized for performance (but it's still very fast).
Single-file MIT licensed library for C/C++
See qoi.h for the documentation and format specification.
More info at https://qoiformat.org
