Patent ID: 8588536

Claim:
A method of compressing digital image data, the method comprising: a. for each image data block in a plurality of image data blocks in the digital image data, splitting the image data in the image data block into luminance data and chrominance data; transforming the luminance data using a two-dimensional integer wavelet transform to convert the luminance data to a low-frequency luminance coefficient and a plurality of high-frequency luminance coefficients; transforming the chrominance data using a two-dimensional integer wavelet transform to convert the chrominance data to a low-frequency chrominance coefficient and a plurality of high-frequency chrominance coefficients; computing a predicted low-frequency luminance coefficient for the luminance data based on at least one neighboring image data block in the plurality of image data blocks; computing a predicted low-frequency luminance coefficient for the chrominance data based on at least one neighboring image data block in the plurality of image data blocks; computing a residual luminance low-frequency coefficient based on the predicted luminance low-frequency coefficient and the low-frequency luminance coefficient; computing a residual chrominance low-frequency coefficient based on the predicted chrominance low-frequency coefficient and the low-frequency chrominance coefficient; selecting a quantization parameter, a luminance entropy coding parameter, and a chrominance entropy coding parameter using rate control, wherein the rate control guarantees a predetermined compression rate; quantizing the plurality of high-frequency luminance coefficients and the plurality of high-frequency chrominance coefficients based on the quantization parameter; entropy coding the residual low-frequency luminance coefficient and the quantized high-frequency luminance coefficients based on the luminance entropy coding parameter; and entropy coding the residual low-frequency chrominance coefficient and the quantized high-frequency chrominance coefficients based on the chrominance entropy coding parameter.