Abstract: A system can include a system processor that is programmed or adapted to classify pixels in a document image, and in some instances, to enhance the document image based upon such classification. Image data including pixels is received. For each pixel in some subset of the image data, a feature vector is generated. Each pixel in the subset is classified as text or image based upon its associated feature vector. The classifications can be outputted for storage and/or further processing. Further processing can include pixel level enhancement processing. Such enhancement processing can include application of a sharpening filter to pixels classified as text and of a smoothing filter to pixels classified as image. In some instances, background suppression can be performed upon a subset of the image data prior to classification.

Abstract: The input pixels in an image to be halftoned using error diffusion are dithered using a first type of passband dither. A second type of passband dither may also be added to a thresholding matrix used in halftoning. This second type of passband dither may be the same as the first type of passband dither. In such case, the second type of passband dither is a scaled multiple of the first type of passband dither. The halftoning process may be implemented in an application specific integrated circuit.

Abstract: The invention provides a system and method for JPEG encoding an image that includes variable quantization for each block, depending upon the classification of each block, which is dependent on the classification of pixels in that block.

Abstract: A system can include a system processor that is programmed or adapted to classify pixels in a document image, and in some instances, to enhance the document image based upon such classification. Image data including pixels is received. For each pixel in some subset of the image data, a feature vector is generated. Each pixel in the subset is classified as text or image based upon its associated feature vector. The classifications can be outputted for storage and/or further processing. Further processing can include pixel level enhancement processing. Such enhancement processing can include application of a sharpening filter to pixels classified as text and of a smoothing filter to pixels classified as image. In some instances, background suppression can be performed upon a subset of the image data prior to classification.

Abstract: A system can include a system processor that is programmed or adapted to classify pixels in a document image, and in some instances, to enhance the document image based upon such classification. Image data including pixels is received. For each pixel in some subset of the image data, a feature vector is generated. Each pixel in the subset is classified as text or image based upon its associated feature vector. The classifications can be outputted for storage and/or further processing. Further processing can include pixel level enhancement processing. Such enhancement processing can include application of a sharpening filter to pixels classified as text and of a smoothing filter to pixels classified as image. In some instances, background suppression can be performed upon a subset of the image data prior to classification.