摘要:
The present invention is a method and apparatus for resolution enhancement of gray-scale input images including text and line art, and more particularly to a filtering method and image processing apparatus for enhancement of high contrast line edges found in continuous tone (gray-scale) images without requiring that the input image data include predetermined tag bits to identify region types (e.g., continuous tone or text and line art).
摘要:
Systems and methods for template matching of multicolored images provide an image conversion process that respectively views two, three or four input color planes through an input observation window. Single plane vectors are obtained that represent the color planes. The obtained single plane vectors are combined into a multi-plane vector that may be used in a look-up table for descreening or resolution enhancement, for example. Various interactions between color planes may be taken into account to provide optimum color space conversion. Additional information obtained by using the multi-plane vector allow performance of image processes with optimized accurate color values.
摘要:
The present invention is a method and apparatus for the enhancement of 1 bit per pixel image signals to produce a multiple-bit per pixel form. A binary input image is passed through a plurality of filters to generate level slices. The filters are stack filters implemented as look-up table or template-based filters, morphological filters, or any similar binary-to-binary filters that could be used to generate level slices. Each of the N-1 filters is used to produce the slices, where N is the number of possible gray-scale levels desired in the output image. Once the slices are generated, the resulting binary image data therein is recombined, by adding or stacking, to produce the desired multiple-bit per pixel output.
摘要:
The present invention is a method and apparatus for the enhancement of 1 bit per pixel image signals to produce a multiple-bit per pixel form. A binary input image is passed through a plurality of filters to generate level slices. The filters are stack filters implemented as look-up table or template-based filters, morphological filters, or any similar binary-to-binary filters that could be used to generate level slices. Each of the N-1 filters is used to produce the slices, where N is the number of possible gray-scale levels desired in the output image. Once the slices are generated, the resulting binary image data therein is recombined, by adding or stacking, to produce the desired multiple-bit per pixel output.
摘要:
An adaptive filtering method and apparatus for descreening a scanned halftoned image representation is disclosed. The apparatus includes an image input subsystem; a processing subsystem for processing halftoned image data provided by the image input subsystem; and software/firmware means operative on the processing subsystem for a) low-pass filtering a halftoned input pixel value provided by the image input subsystem to produce a low-pass filtered pixel value; b) notch-filtering the halftoned input pixel value to produce a notch-filtered pixel value; c) determining a local contrast value for the halftoned input pixel value; and d) producing a descreened output pixel value based on the low-pass filtered pixel value, the notch-filtered pixel value, or a combination of the low-pass filtered pixel value and the notch-filtered pixel value depending on the local contrast value.
摘要:
The present invention is a method and apparatus for applying magnetic ink character recognition (MICR) technology to enable the embedding of coded information within text characters of a document.
摘要:
The method and system of this invention predictively encodes and decodes an image signal that has been treated with the Roberts Method. The method and system generates a noise signal that is substantially similar to the noise signal generated during the Roberts Method treatment, calculates a range of values for the original image signal based upon an image signal from a different pixel location, predicts the image signal based upon the range of values and the noise signal and calculates an error signal that is encoded. The decoding method and system operates in reverse of the encoding method and system.
摘要:
A system and method for classifying an image block of a printed image into contone, halftone, or error diffusion classes, includes scanning the printed image; selecting an n by n block of pixels from the scanned image in a luminance channel; calculating an array of DCT coefficients of the pixel block, wherein the calculated DCT coefficients are representative of spatial frequency and spatial orientation of the pixel block; comparing the array of DCT coefficients with an array of predetermined values, wherein the array of predetermined values are indicative of contone, halftone and error diffusion classes; and determining the image classification of the pixel block based on the comparison of the DCT coefficients with the array of predetermined values. If the image is determined to be halftone, then the method further evaluates the DCT coefficients to determine the frequency of the halftone screen.
摘要:
A system and method for classifying an image block of a printed image into contone, halftone, or error diffusion classes, includes scanning the printed image; selecting an n by n block of pixels from the scanned image in a luminance channel; calculating an array of DCT coefficients of the pixel block, wherein the calculated DCT coefficients are representative of spatial frequency and spatial orientation of the pixel block; comparing the array of DCT coefficients with an array of predetermined values, wherein the array of predetermined values are indicative of contone, halftone and error diffusion classes; and determining the image classification of the pixel block based on the comparison of the DCT coefficients with the array of predetermined values. If the image is determined to be halftone, then the method further evaluates the DCT coefficients to determine the frequency of the halftone screen.
摘要:
Method and apparatus for processing a stream of image pixel data to determine the presence of high frequency half-tone data. The arrangement applies the function ##EQU1## to a stream of image pixel data. The presence of minimums of .phi.(k) at times indicative of predetermined half-tone image frequencies is detected and an output signal indicative of the presence or absence of minimums at the predetermined half-tone image frequencies is provided. More particularly, the two's complement of the stream of image pixel data is added to each of a plurality of differently delayed signals derived from the original stream of image pixel data. The absolute value is taken of the resulting function. The signal is summed for a selected number of pixels, corrected for noise, and reviewed for minimums. Minimums occurring at selected positions in the pixel stream indicate certain frequencies of the data. An output is created based on frequency indications.