Patent ID: 7526133

Claim:
An image processing apparatus comprising: a compression coding unit to perform compression coding of image data according to JPEG2000 algorithm, wherein the compression coding includes DC-level shifting processing, color transform processing, 2-dimensional discrete wavelet transform processing, quantization processing, coefficient bit modeling processing, arithmetic entropy coding processing, and data ordering control processing; and a coding style selection unit to selectively activate coding functions of the compression coding unit to cause the active coding functions of the compression coding unit to be suited to characteristics of the image data, wherein a coding style mode, specifying the selective activation of the coding functions of the compression coding unit by the coding style selection unit, is dynamically switched per a portion of the image data between different coding style modes; an image property discriminating unit to distinguish the characteristics of the image data and outputting a discriminating signal indicating the characteristics of the image data, wherein at least one of the compression coding unit, the coding style selection unit, and the image property discriminating unit are implemented with a processor; wherein the DC-level shifting processing, the color transform processing, the 2-dimensional discrete wavelet transform processing, and the quantization processing are subjected to the selective activation of the coding functions by the coding style selection unit in response to the discriminating signal, and wherein the coding style selection unit activates the processing operations of DC-level shifting, color transform, 2-dimensional discrete wavelet transform and quantization in the compression coding unit when the discriminating signal indicates a natural image, the coding style selection unit deactivating the processing operations of DC-level shifting, color transforming, 2-dimensional discrete wavelet transform and quantization in the compression coding unit when the discriminating signal indicates a palletized image or a bi-level image, the coding style selection unit activating only the quantization processing optionally when the discriminating signal indicates a computer graphics image, and the coding style selection unit activating the processing operations of DC-level shifting, 2-dimensional discrete wavelet transform and quantization in the compression coding unit when the discriminating signal indicates a monochrome image.