A JPEG encoder in a single C++ file

This is a mirror of my library hosted at https://create.stephan-brumme.com/toojpeg/

TooJpeg is a compact baseline JPEG/JFIF writer, written in C++11 (but looks like C for the most part).
Its interface has only one function: writeJpeg() - and that's it !

My library supports the most common JPEG output color spaces:

• YCbCr444,
• YCbCr420 (=2x2 downsampled) and
• Y (grayscale)

Saving NASA's huge 21600x10800px blue marble image with quality=90 takes just 2.4 (YCbCr420) or 3.6 seconds (YCbCr444) on a standard x64 machine - faster than other small JPEG encoders.
The compiled library enlarges your binary by about 7kb (CLang x64) or 12kb (GCC x64) in -O3 mode.
Far more details can be found on the project homepage: https://create.stephan-brumme.com/toojpeg/

How to use

1. create an image with any content you like, e.g. 1024x768, RGB (3 bytes per pixel)

   auto pixels = new unsigned char[1024*768*3];

2. define a callback that receives the compressed data byte-by-byte

// for example, write to disk (could be anything else, too, such as network transfer, in-memory storage, etc.)
void myOutput(unsigned char oneByte) { fputc(oneByte, myFileHandle); }

3. start JPEG compression

TooJpeg::writeJpeg(myOutput, mypixels, 1024, 768);
// actually there are some optional parameters, too
//bool ok = TooJpeg::writeJpeg(myOutput, pixels, width, height, isRGB, quality, downSample, comment);