Abstract: A density converting unit converts densities concerning respective color components in color-image data for each pixel so as to change the densities concerning respective color components for the pixel into lower densities when the densities concerning respective color components for the pixel are determined to be white or approximately white. The density converting unit converts the densities concerning color components in the color-image data for each pixel so as to change the densities concerning respective color components for the pixel into densities corresponding to white ones when all of the densities concerning respective color components for the pixel are lower than a predetermined threshold density value.

Abstract: A color correction apparatus includes a preprocessor for generating a minimum value signal, a set of difference signals, and a selecting signal in accordance with values of input XYZ color data, the minimum value signal indicating a minimum value among the input XYZ color values, the difference signals indicating differences between the minimum value and the remaining values of the input XYZ color data, and the selecting signal being used to select one of unit triangular prisms in XYZ color space, a first part for computing a first signal of output color data through interpolation being performed, using predetermined values of output colors corresponding to lattice points of the selected unit triangular prism, in accordance with a value of the minimum value signal and in accordance with values of the difference signals, a second part for computing a second signal of the output color data in accordance with the value of the minimum value signal, and a third part for generating a third signal indicating the out

Abstract: An image region segmentation system includes a first detection part for detecting a candidate region for a text region within an image, a second detection part for detecting a white region within the image by carrying out a pattern matching of a matrix including a pixel of the image with predetermined matrix patterns for a set of successive white pixels, and a discrimination part for detecting whether or not the candidate region detected by the first detection part is a text region by checking if a white region is detected in a neighborhood of the detected candidate region.

Abstract: A color correction apparatus includes a preprocessor for generating a minimum value signal, a set of difference signals, and a selecting signal in accordance with values of input XYZ color data, the minimum value signal indicating a minimum value among the input XYZ color values, the difference signals indicating differences between the minimum value and the remaining values of the input XYZ color data, and the selecting signal being used to select one of unit triangular prisms in XYZ color space, a first part for computing a first signal of output color data through interpolation being performed, using predetermined values of output colors corresponding to lattice points of the selected unit triangular prism, in accordance with a value of the minimum value signal and in accordance with values of the difference signals, a second part for computing a second signal of the output color data in accordance with the value of the minimum value signal, and a third part for generating a third signal indicating the out

Abstract: A color correction apparatus includes a preprocessor for generating a minimum value signal, a set of difference signals, and a selecting signal in accordance with values of input XYZ color data, the minimum value signal indicating a minimum value among the input XYZ color values, the difference signals indicating differences between the minimum value and the remaining values of the input XYZ color data, and the selecting signal being used to select one of unit triangular prisms in XYZ color space, a first part for computing a first signal of output color data through interpolation being performed, using predetermined values of output colors corresponding to lattice points of the selected unit triangular prism, in accordance with a value of the minimum value signal and in accordance with values of the difference signals, a second part for computing a second signal of the output color data in accordance with the value of the minimum value signal, and a third part for generating a third signal indicating the out

Abstract: A size magnification processing unit processes an original digital image in accordance with a magnification factor. The size magnification unit includes a smoothing unit for processing the original digital image under a smoothing characteristic and for obtaining a smoothed image, a controller for controlling the smoothing characteristic in accordance with the magnification factor, under which characteristic the original digital image is to be processed, and an interpolation unit for performing an interpolation process in which image data of pixels arranged at sampling intervals depending on the magnification factor is calculated based on the smoothed image supplied from the smoothing unit. The interpolation characteristic under which the interpolation process is to be performed by the interpolation unit may be controlled in accordance with the magnification factor. The smoothing characteristic and the interpolation characteristic may be controlled in accordance with a type of the original image.

Abstract: An interpolation method for color correction generates correction signals Y, M and C from input signals R, G and B through interpolation. In this interpolation method, a triangular prism is selected from plural unit triangular prisms in RGB space, based on x, y and z coordinates of the input signals, a gradient factor and an intercept factor of the selected prism are read out from a memory, and correction data corresponding to the input signals is calculated through interpolation using the gradient and intercept factors from the memory, so that the correction signals are generated based on the calculated correction data.

Abstract: A line region segmentation method includes the steps of grouping pixels of an input image indicated by image signals into three sets of black, gray and white pixels, performing a pattern matching of black pixels in a region of the input image with a set of matrix patterns to determine if a black pixel is closely associated with other pixels and determine if a black pixel is one of screened black pixels for each pixel of the set of black pixels, deciding if the black pixel being considered is one of black bilevel pixels by checking the number of black pixels that are determined as being associated black pixels and as being non-screened black pixels, performing a pattern matching of white pixels in a region of the input image with a set of matrix patterns to determine if a white pixel is closely associated with other pixels for each pixel of the set of white pixels, deciding if the white pixel being considered is one of white bilevel pixels by checking the number of white pixels that are determined as being ass

Abstract: An image region segmentation system for segmenting a color image into a number of elemental regions according to the type of images contained in the elemental region comprises a first detection circuit for discriminating whether an elemental region under processing contains a black pixel or not, a second detection means for discriminating whether the elemental region under processing contains a color pixel or not, a first discrimination circuit for discriminating the elemental region as to whether or not the region includes a black pixel and simultaneously no color pixels, a line image recognition circuit for discriminating as to whether the image in the elemental region under processing includes a line or not, and a second recognition circuit for discriminating such that the elemental region under processing represents a bi-level black line when the elemental region under processing contains a black pixel and simultaneously no color pixels and further simultaneously when the elemental region represents a lin

Abstract: A color document or color video information is inputted to a system which corrects the color of the images scanned or inputted by using data indicative of the conditions under which the color document or color video information was prepared. Color compensation coefficients are used to correct for color distortions that might have occurred in the color document or in the color video information. The color distortions of the input document or those of the color video signal relative to an original are provided as data values of a function of three primary color separation signals, so that color compensation may be performed by an inverse processing of the same data function. This allows for a more accurate and faithful reproduction of the color image.

Abstract: A method of describing an image made up of a plurality of kinds of regions in an n-dimensional space by a tree structure, comprises the steps of recursively and equally dividing the image into 2.sup.n regions until each region includes two or less kinds of regions, thereby making a first level of the tree structure, and recursively and equally subdividing each of the 2.sup.n regions into 2.sup.n subregions until each subregion includes only one kind of region and for describing only one of two kinds of regions by a tree structure in which each parent node which degree is one and only having one branch is integrated into a filial node thereof, thereby making a second level of the tree structure. Each filial node in the second level of the tree structure is added with first division information described by sequential data of 2.sup.

Abstract: Any desired screen angle is obtained through calculation for coordinate conversion. Since the screen angle can be set to any desired value for each color used in color recording, a moire can be prevented. The memory capacity required for a memory constituting a threshold table is reduced. The interporation processing is performed to make small an error in calculations. The linear interporation method, the distance allocation method, cubic convolution, etc. are available. Data for respective values of R, G and B in association with the elements of masking equations used in determining Y, M and C, each element including the function of second or higher degrees, have been previously stored in the form of a table, and the respective data obtained by referring to the table with R, G and B as parameters are calculated to obtain Y, M and C.

Abstract: An interpolation method for color correction generates correction signals Y, M and C from input signals R, G and B through interpolation. In this interpolation method, a triangular prism is selected from plural unit triangular prisms in RGB space, based on x, y and z coordinates of the input signals, a gradient factor and an intercept factor of the selected prism are read out from a memory, and correction data corresponding to the input signals is calculated through interpolation using the gradient and intercept factors from the memory, so that the correction signals are generated based on the calculated correction data.