Enhancement of compressed image data

An image processing method comprising:

• receiving wavelet-domain data defining a digital image, the wavelet-domain data comprising N levels of decomposition;
• inputting M levels of decomposition into an automated image enhancement system, where M is less than N;
• from the M levels of decomposition, deriving at least one of a correction tone reproduction curve and a sharpness filter for enhancement of the input digital image data;
• decompressing the image data to obtain decompressed image data representing the input digital image at a selected level of decomposition;
• and,
• using the at least one of said final tone reproduction curve and said sharpness filter to enhance the decompressed image data.

A xerographic apparatus which processes wavelet-domain image data comprising:

• means for receiving the wavelet-domain image data representative of an input digital image, said wavelet-domain image data including N-levels of wavelet decompositions;
• an M-level extractor which extracts an Mth level wavelet decomposition from the wavelet-domain image data where M is less than N, the extracted Mth level wavelet decomposition being a low resolution representation of the input digital image;
• and
• an image enhancement system which receives the extracted Mth level wavelet decomposition, the system deriving an enhancement process from the extracted Mth level wavelet decomposition to adjust a high resolution representation of the input digital image.