Array quantization and compression.

Installation

Pkg.add("QuantizedArrays")

Examples

• Vector quantization

using QuantizedArrays
v = collect(1:10);

# Use 3 quantization levels (always 1 codebook)
qv = QuantizedArray(v, k=3)
# 10-element QuantizedArray{QuantizedArrays.OrthogonalQuantization,UInt8,Distances.SqEuclidean,Int64,1}:
#   5
#   5
#   5
#   5
#   5
#   6
#   6
#   6
#  10
#  10

• matrix quantization

using QuantizedArrays
m = reshape(collect(1:60), (6,10))
# 6×10 array{int64,2}:
#  1   7  13  19  25  31  37  43  49  55
#  2   8  14  20  26  32  38  44  50  56
#  3   9  15  21  27  33  39  45  51  57
#  4  10  16  22  28  34  40  46  52  58
#  5  11  17  23  29  35  41  47  53  59
#  6  12  18  24  30  36  42  48  54  60

# use 5 quantization levels (vectors) / codebook and 2 codebooks
qm = QuantizedArray(m, k = 5, m = 2)
# 6×10 QuantizedArray{QuantizedArrays.OrthogonalQuantization,UInt8,Distances.SqEuclidean,Int64,2}:
#   7   7  13  13  31  31  43  43  43  55
#   8   8  14  14  32  32  44  44  44  56
#   9   9  15  15  33  33  45  45  45  57
#  10  10  10  28  28  34  40  46  46  46
#  11  11  11  29  29  35  41  47  47  47
#  12  12  12  30  30  36  42  48  48  48

Features

To keep track with the latest features, please consult NEWS.md and the documentation.

License

The code has an MIT license and therefore it is free.

Reporting Bugs

This is work in progress and bugs may still be present...¯\(ツ)/¯ Do not worry, just open an issue to report a bug or request a feature.

References

• Rayuela.jl provides an extensive list of quantization methods implementations as well as good references pertinent to the state-of-the-art.

• Quantization in signal processing (Wikipedia)

• Vector quantization (Wikipedia)