Compress less than 1 byte symbol data

[cevek]

Can I compress data with using less than 1 byte per symbol, for example 5bits?
I have some image data using only 32 colors - 5 bits per pixel, and so I need to compress it 🔢 :)
How can I do that? Or only 1 byte per pixel?

[powturbo]

You'll get better results with byte aligned and uncompressed skewed data with lot of repetitions. For example BMP images. See the benchmark on the readme file.

[cevek]

So, I reduce colors to 16(4bits per pixel) and align 2pixels into 1 byte
Results is very different:

Original: 1024000
1 byte aligned: 
    TRLE: 115822
    LZ4:   89738
1 byte 2 pixels: 
    TRLE: 79861
    LZ4:  67699