| 摘要 |
A method of processing an image includes the step of transforming spatial image data to generate a first set of frequency domain basis coefficients. The first set of basis coefficients is combined with a second set of basis coefficients corresponding to a frequency domain transform of a pre-determined halftone texture. In various embodiments, the forward transform is a selected one of the discrete cosine transform, the discrete sine transform, and the Fourier transform. The combined basis coefficients are quantized and entropy encoded to generate the compressed image data. After any necessary decompression, an inverse transform may be subsequently performed to reconstruct the source spatial image with the pre-determined halftone texture. In one embodiment, a method of processing a source image includes the step of scanning the source image to generate digitized spatial image data. The digitized data is subdivided into a plurality of blocks. A forward transform is applied to each block to generate source image basis coefficients. The source image basis coefficients are then combined with halftone basis coefficients corresponding to a pre-determined halftone texture. The combined basis coefficients may be quantized and entropy encoded to generate the compressed image data. After decompression, the spatial image reconstructed through inverse transformation incorporates the pre-determined halftone texture.
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