Integer-based wavelet transform coding for near lossless compression of medical images

A unified lossless and lossy compression algorithm is proposed using integer-based reversible wavelet transforms. The proposed algorithm is based on improved pre-quantization, integer-based wavelet transform, and bit plane coding of wavelet bands with QM coder. From simulation, reconstructed image by the proposed algorithm shows higher peak signal-to-noise ratio (PSNR) compared to those obtained by float-point-based wavelet transform (Daubechies) and the JPEG. Peak errors in the reconstructed images by the integer-based wavelet transform are also much lower than those obtained by the JPEG and the float-point-based wavelet coding. In near lossless compression, lossless encoding of the wavelet coefficients of the prequantized image shows higher PSNR than those with the bit rate control by the bit plane-band ordering of the wavelet coefficients of the original image without pre-quantization. Using pre-quantization controlled, which may be an important feature in medical image compression, Using pre-quantization, peak error can also be uniquely controlled, which may be an important feature in medical image compression.