A C++ implementation for the QOI (The Quite OK Image Format for Fast, Lossless Compression) format

templated, header only, operating on containers, C++17(could probably be lower)

---

target_link_libraries( ${Target} PRIVATE sgs::qoi )

#include <sgs/qoi.hpp>

decoding

 std::vector<uint8_t> data;
 // load qoi file data
 sgs::qoi::DataPair decoded = sgs::qoi::decode(data);
 // decoded.data (raw pixel data)
 // decoded.header (width, height, channels, colorspace)
 sgs::qoi::Header header = sgs::qoi::readHeader(data);
 // header (width, height, channels, colorspace)

encoding

 std::vector<uint8_t> data;
 // load raw pixel data
 sgs::qoi::Header header{
     300, 200, // width, height
     sgs::qoi::Channels::RGB,
     sgs::qoi::Colorspace::Linear
 };
 std::vector encoded = sgs::qoi::encode(header, data);
 // encoded (QOI file data (header, packets & endmarker))

specifying the output container type

 sgs::qoi::DataPair decoded = sgs::qoi::decode<std::deque<uint8_t>>(data);
 std::deque encoded = sgs::qoi::encode<std::deque<uint8_t>>(header, data);

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using the library itself has no dependencies beyond the standard library

tests and benchmark do however make use of other libraries:

repo	license	language	used in
Catch2	BSL	C++	bench & test
phoboslab/qoi	MIT	C	bench & test
pfusik/qoi-ci	MIT	Ć, (C, C++)	bench
ShadowMitia/libqoi	MIT	C++	bench
wx257osn2/qoixx	MIT	C++20	bench
shraiwi/mini-qoi	MIT	C, (C++)	bench

to build benchmarks and tests enable the cmake options ENABLE_BENCHMARK & ENABLE_TESTS

for the purpose of benchmarking and testing all implementations are used through a common virtual interface, the timings below may therefore not reflect the best performance one could achieve

all functions are benched against a set of example images, that you can find on the qoi website, on an Intel i7-5820K (3.6GHz) Windows 10

encoding	msvc	clang-cl	mingw
stillgreensan::qoi::encode	33.5666 ms	41.5951 ms	29.9616 ms
phoboslab::qoi::encode	28.4051 ms	26.3849 ms	23.9919 ms
shadowmitia::libqoi::encode	36.2259 ms	32.4339 ms	31.3426 ms
wx257osn2::qoixx::encode	32.1062 ms	26.3908 ms	22.0142 ms

decoding	msvc	clang-cl	mingw
stillgreensan::qoi::decode	29.8009 ms	26.3818 ms	24.2907 ms
phoboslab::qoi::decode	19.1761 ms	21.6312 ms	20.3470 ms
pfusik::qoici::c::decode	17.3896 ms	17.5273 ms	16.3815 ms
pfusik::qoici::cpp::decode	17.9252 ms	18.5737 ms	17.4916 ms
shadowmitia::libqoi::decode	21.0683 ms	22.1937 ms	20.0901 ms
shraiwi::miniqoi::c::decode	45.3839 ms	47.1148 ms	30.3102 ms
shraiwi::miniqoi::cpp::decode	46.2561 ms	47.5463 ms	30.5549 ms
wx257osn2::qoixx::decode	18.8729 ms	15.9443 ms	16.3083 ms