dwt based image compression

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Jitesh Bhanushali
Jitesh Bhanushali on 24 Apr 2014
Answered: Walter Roberson on 24 Apr 2014
sir how we can do quantization in image compression using dwt??
how can we compress image using dwt?

Answers (1)

Walter Roberson
Walter Roberson on 24 Apr 2014
Do the dwt. You will get a vector of coefficients as output. Store only the first 42 coefficients for each block, discarding the rest. The result will be a file that is 42 / (8*8) = 62.625% as large as the original image, because the original image had one coefficient for every pixel, 64 coefficients for each 8*8 block.
When you want to decompress, load the coefficients back in, storing the 42 coefficients into each 8 * 8 block, and set the "missing" (64-42 = 22) coefficients to 0. Then do the inverse dwt.

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