Lossless and near-lossless image compression with color transformations

A comparison of lossleess compression results is given for RGB, YCRCB and reversible JPEG 2000 color space. The paper describes the general conditions that rounding errors of a color transformation do not cumulate in the consecutive cycles of forward and inverse transformation. In particular, rounding errors of the RGB → YCRCB → RGB transformation do not accumulate in the consecutive transformation cycles. Luminance and chrominance representation with two additional bits leads to perfectly reversible color transformation. For such representation compression is slightly better than in RGB but worse as in the JPEG 2000 reversible color space. The paper comprises study on accumulation of errors produced by near-lossless JPEG-LS in the consecutive compression-decompression cycles. Paper proves that alternatively, lossless compression can be performed on luminance and chrominance with reduced representation bit numbers. The advantage is that the errors do not accumulate in the consecutive cycles of compression.