Manual

Obtaining CvxCompress.jl

1. From the Julia prompt, ]add CvxCompress
2. (optional) From the Julia prompt ]dev CvxCompress

Building CvxCompress.jl

CvxCompress.jl depends on CvxCompress, written by Thor Johnsen. To re-download and re-build CvxCompress, do:

]build CvxCompress

Using CvxCompress.jl

3D

using CvxCompress

n1,n2,n3 = 100,200,300
volume = rand(Float32,n1,n2,n3)
compressed_volume = zeros(UInt32,n1*n2*n3)
decompressed_volume = zeros(Float32,n1,n2,n3)

b1,b2,b3,scale=16,16,16,1e-3
c = CvxCompressor((b1,b2,b3), scale)
nbytes = compress!(compressed_volume, c, volume)
decompress!(decompressed_volume, c, compressed_volume)

2D

using CvxCompress

nz,nx = 100,300
volume = rand(Float32,n1,n2)
compressed_volume = zeros(UInt32,n1*n2)
decompressed_volume = zeros(Float32,n1,n2)

c = CvxCompressor((b1,b2),scale)
nbytes = compress!(compressed_volume, c, volume)
decompress!(decompressed_volume, c, compressed_volume)

Options

In the above examples we have,

• b1=32,b2=32,b3=32 block size used for compression where b1 is fast and b3 is slow. These must be powers of 2, and between 8 and 256.
• scale=1e-2 scale factor used to determine the thresholding of the wavelet coefficients