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Serious problem with quantization during lossy encoding #615

@boxerab

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@boxerab

Subband stepsize is always less than one in OpenJPEG. This means that quantization is not taking place: i.e. DWT coefficients are being mapped to a larger dynamic range, rather than a smaller one,
since quantization take place by multiplying coefficients by the reciprocal of the step size.

This is very inefficient. I don't think this is a conformance issue, because encoders are free to choose the quantization step. But, I would guess this situation creates a serious hit in performance - perhaps at least two times slower than with a proper step size.

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