Abstract: A method for adjusting the color reproduction of a color image composed of pixels provided in a plurality of color channels is based on generating a reference image from a combination of the color channels, whereby each spatial coordinate of the reference image is characterized by a reference image level. Channel averages of the color channel values of the pixels that correspond to each of at least two different valued reference image levels are generated. Specific channel averages are obtained corresponding to a near white point and a near black point from the channel averages. The specific channel averages are utilized on a pixel by pixel basis for the respective channels of the digital color image to produce a processed digital color image having improved color reproduction.

Abstract: A method for adjusting the tone scale reproduction of a color image composed of pixels provided in a plurality of color channels is based on generating a reference image from a combination of the color channels, whereby each spatial coordinate of the reference image is characterized by a reference image level. Channel averages of the color channel values of the pixels that correspond to the different valued reference image levels are generated. A channel tone scale transformation is formed by relating each channel average to its corresponding reference image level, and the channel tone scale transformation is utilized on a pixel by pixel basis in the respective channels of the digital color image to produce a processed digital color image having improved tone scale reproduction.

Abstract: A system and method for automatically adjusting color parameters during a film-to-digital transfer. An operator uses standard telecine equipment to preview scenes in order to determine a natural clustering of fields or scenes. Each cluster is processed separately. All the fields in a cluster are treated as one unit in the sense that color adjustments for the cluster are based on the cluster color histogram, which is computed by aggregating the colors from all pixels in the cluster. Constraints are specified for the cluster. Variables of a constraint may be automatically specified or determined by an operator based on observing sample frames from the cluster. In addition, the operator can nullify a constraint if desired. Within each cluster, the system adjusts red, green and blue intensities of the digitizing device, gains for each of these color channels, and other parameters. The system first determines which settings respect the constraints and then optimizes the solution.

Abstract: A method corrects a color image by avenging at least two color channels in regions near the minimum of histograms of the at least two color channels; selecting the smallest of the avenge color values as a black point; averaging at least two color channels in regions near the maximum of the histograms of the at least two color channels and selecting the largest of the avenge color values as the white point; and correcting the at least two color channels by adjusting the smallest and the largest color averages to respectively match the valves of the black point and the white point to form corrected image data. A preferred method limits the adjustment to a predetermined amount of clipping of the at least two color channels.

Abstract: An image correction apparatus includes: an image obtaining unit that obtains image data from outside constituted of a plurality of pixels each having a value in a color component among a plurality of color components; an average value calculation unit that calculates average values of color component values corresponding to individual color components in the image data; and a correction unit that corrects the color component values of individual pixels to match the average values of the color component values corresponding to individual color components with at least one specific reference value.

Abstract: An adaptive image tone mapping curve based on perceptual preference guidelines is generated as a sigmoidal function, in which the sigmoidal function parameters (slope and shift) are determined by original image statistics. Tone curves generated for different images each have a smooth sigmoidal shape, so that the tone mapping process does not change the image histogram shape drastically. The sigmoidal function has the form: t ? ( x ) = 100 1 + exp ? ( - ? ? ( x / 100 - ? ) ) , where ? is the slope parameter and ? is the shift parameter. The input value x in the sigmoidal function varies in the range [0, 100], because the tone curve is generated on an L* scale, which has values from 0 to 100.

Abstract: In a color correction apparatus 1, a representative color extracting unit 13 reads from an object color information memory 12 a hue distributable region of an object selected by an object selecting unit 11 and the distribution frequency in each split hue region to extract a representative color. A color correction parameter determining unit 15 determines from the memory content of a color correction parameter memory 14 optimum color correction parameters adapted to the representative color extracted by the representative color extracting unit 13. A color correction processing unit 16 carries out, upon an input image, color correction acting only upon the representative color of the object and neighborhood colors therearound.

Abstract: A color image processing apparatus and method capable of changing/converting an inadequate-exposure image or an over-exposure image into an apparently natural image or a pleasing-lightness image. The apparatus is equipped with an object color designating section for designating an object color in an input color image, an optimum color setting section for setting an optimum color corresponding the object color, a lightness conversion factor obtaining section for obtaining a lightness conversion factor based on the object color and the optimum color, and a lightness converting section for converting the lightness of the color image using the lightness conversion factor to create a lightness-changed color image. This apparatus is useful in correcting lightness over a color image input from a digital camera, an image scanner or the like.

Abstract: On the basis of a discrimination parameter for discriminating more detailed brightness in an image, the brightness of the image is discriminated, and the optimum degree of correction component is set for the image, thereby performing a more faithful reproduction of the image indicated by image data. Therefore, a highlight point being a brightness value associated with a cumulative frequency of reaching a predetermined value is calculated in a high-brightness area on the basis of a histogram obtained with respect to the number of pixels of a brightness value indicated by the image data, and the image is discriminated in its entire brightness on the basis of the highlight point. On the other hand, a ratio of the cumulative frequency in a predetermined low-brightness area to the number of all the pixels in the histogram is calculated. On the basis of the calculated ratio and the discriminated brightness, a gamma value indicating degree of correction the brightness value to a value of more light image is defined.

Abstract: An image processing apparatus, method and computer program product, wherein a luminance histogram of input image data is generated by the histogram generating section and a polarization degree of the luminance histogram is evaluated by the polarization degree evaluating section in order to determine whether the input image data is in a true backlight condition or in a halation condition. An optimum dynamic range correction and tone curve correction are performed on the input image data based on a result of the above-described determination.

Abstract: In performing automatic white balance of a digital image, a signal is obtained from an image sensor, which represents data corresponding to an image. A plurality of channels is obtained from the signal. A mean value for each of the plurality of channels is determined using a histogram. An average dynamic range is determined from the signal using a histogram. A difference or ratio between one or more of the mean values and the average dynamic range is determined, and that difference or ratio defines a white balance correction. The white balance of the image is then adjusted using the white balance correction.

Abstract: An image processing apparatus creates a pixel value histogram of an objective image, and approximates a predetermined range of the created histogram by a bended line formed from two straight lines. Then the apparatus extracts a pixel value at a boundary between a predetermined region and another region of the objective image in accordance with the approximation.

Abstract: In a recording device, electrostatic recording units of Y, M, C and K are arranged along the direction of the feed of a recording sheet by a belt unit. The device forms latent images corresponding to image data by optical scanning of an exposure device onto a rotating photosensitive drum, develops the latent images with toner components having different colors, and then transfers the developed images onto the recording sheet on the belt unit. A color matching processing unit performs color matching processing including color slippage correction of different color images. An automatic color matching mode processing unit works the color matching processing unit when conditions beforehand decided in the state that an automatic correction mode is set up are realized.

Abstract: Specialized encoded media are detected when inserted into the multipurpose paper input tray of the printer. Each specialized media is displayed in a list of available media provided by the web-based imaging service. Graphics representing each of the specialized media are downloaded e.g., from a site on the Internet accessed through information encoded on the specialized media, and are displayed to provide a preview of the user's image data superimposed in register on an image of the specialized media. In a variation, the multipurpose tray includes an integral bar code scanner that automatically identifies the specialized media. Among other variations, the multipurpose tray uses the motion of insertion to scan the specialized media, and inks “visible” only through infrared scanning mechanisms are encoded on the media.

Abstract: A method is provided for automatically adjusting the color of a digital image. In one aspect, an strength offset is determined to automatically remove gray from a distorted image. In an other aspect applied independently or after gray removal, scaling factors are automatically determined to adjust the image to conform to empirically determined optimal brightening of the image. Using a determination of color dot maximums and a function which ensures constraint within the dynamic range, scaling factors are established which correspond to the strength values of each dot maximum and which are applied to each of the dot's R,G and B to maintain ratios therebetween and thus maintain the true color. The function for establishing the scaling factors is interpolated from a nominal function and a target average strength for the image.

Abstract: A color conversion section converts R-, G- and B-image signals input by the reading of a color image on an original to C-, M- and Y-color signals. A histogram producing means of an image processing section produces density histograms of the respective color signals on the basis of the converted C-, M- and Y-color signals. An original type determination means determines a type of the original on the basis of the histogram data signals. A colored background determination means determines a colored background on the basis of the histogram data signals. A background process presence/absence determination means determines whether a background process is to be executed or not, on the basis of an original type determination result signal and a colored background determination result signal. A CPU produces, when it is determined that the background process is to be executed, a background process table using the density histogram values of the respective color signals.

Abstract: A method for converting a document into a full-page image using a graphical device interface (GDI) of an operating system is disclosed. The GDI provides objects of the document and coordinates of the objects in the document. The document is divided into a plurality of blocks. An address array having a plurality of address units is established to record the coordinates of the objects. Each of the address units corresponds to one of the blocks and is used to record positions of the objects in the block. The positions recorded in the address units are updated according to the coordinates of the objects provided by the GDI. A corresponding image piece for each block is generated according to the updated positions recorded in the corresponding address unit. All of the image pieces are merged into the full-page image.

Abstract: This invention provides an image processing device in which a pixel satisfying a certain unwanted gradation condition with respect to all the plurality of color components is judged as a unwanted pixel derived from unnecessary image data, and each of gradation data of the plurality of color components composing the unwanted pixel is converted into a certain background gradation which is predetermined with respect to each one of the color components. The image processing device eliminates a possibility that a pixel satisfying the unwanted gradation condition with respect to part of the color components is judged as the unwanted pixel. This arrangement enables to securely extract and remove the unwanted pixel attributed to the unnecessary image data such as undertone and backside image data and prevents degraded image reproduction due to color change resulting from erroneous removal of part of the color components of the necessary image data.

Abstract: An image processing apparatus, method and computer program product, wherein a luminance histogram of input image data is generated by the histogram generating section and a polarization degree of the luminance histogram is evaluated by the polarization degree evaluating section in order to determine whether the input image data is in a true backlight condition or in a halation condition. An optimum dynamic range correction and tone curve correction are performed on the input image data based on a result of the above-described determination.

Abstract: A flesh tone region detection processor (12) detects a flesh tone region from a color still image, and a projective distribution generator (13) generates the projective distribution of the detected flesh tone region. A facial region search processor (14) searches the projective distribution for a parabola using, e.g., a genetic algorithm, and extracts a facial region candidate from the position of the found parabola. A knowledge processor (15) checks based on the aspect ratio of the region, matching with facial patterns prepared in advance, or the presence/absence of a region corresponding to hair if the extracted facial region candidate is a facial region. The user can set the processing time, the number of persons to be detected, and the face area ratio as a search end condition.

Abstract: Pixel characteristics, such as whether a pixel forms part of the background of an image, are evaluated by computing histograms from pixel color space components, by comparing pixel color space components to threshold values, or by other methods.

Abstract: When a color image is input, a histogram is generated for each primary color, and a luminance value having the highest frequency is obtained. Next, a luminance value that will become a background candidate is decided in the neighborhood of the luminance value having the highest frequency for each primary color. A value equal to or larger than the decided luminance value is defined to be a background candidate. Additionally, a background color is decided within a background candidate luminance area. By replacing the pixels within the background candidate luminance area with the decided background color, a reverse-side visible portion is removed while maintaining the appearance of the background.

Abstract: A method is disclosed for changing the dynamic range of an original input image to more closely match the dynamic range of the medium used for a reproduction. The method includes creating an output image by preserving small contrast differences between different areas of the original input image and limiting the maximum contrast differences between different areas of the original input image. The method also includes creating a mask by subtracting the original input image from the output image, scaling the mask, and creating a new output image by adding the scaled mask to the original input image.

Abstract: Upon executing auto color select (ACS) generally, since a prescan for ACS must be done before a main scan for capturing actual image data, a long processing time is required, resulting in low productivity. In this invention, an ACS task is executed while the scanner is making an image capture scan. If the ACS task determines that the captured original is a color original, the ACS task informs the printer of that information, and then normally terminates itself. After the end of scan, if it is not determined that the original is a color original, information indicating that the original is a monochrome original is sent to the printer. Hence, appropriate ACS can be done without any prescan.

Abstract: Optimally determined halftoning algorithms are applied to tone values by selecting among combinations of at least two algorithms that best address the tradeoff between output quality and rendering performance. Input tone values are scrutinized and matched with the algorithm combination that processes the associated tone values in a manner that increases performance (including data compressibility) without sacrificing output quality. The selection process is computationally simple and fast. Reliability is ensured because the combinations of halftoning algorithms are tabulated as a result of analysis of test samples of the printed output.

Abstract: A histogram is prepared by calculating the pixel number ratio corresponding to each gradation in relation to the total number of pixels in image data obtained from the outside. A threshold value for the pixel number ratio corresponding to a given gradation that is determined through user specification is compared against the pixel number ratio corresponding to each gradation in the histogram. Based upon the results of the comparison, the histogram gradation width is corrected. For instance, the width representing the range of gradations with pixel number ratios smaller than the threshold value in the histogram is compressed. Then, the gradation width in the histogram is expanded to achieve the number of pre-compression gradations.

Abstract: The exposure control device has a line sensor sensing image data corresponding to a color image recorded in a negative film. The line sensor is exposed using first, second and third exposure times so that image data are obtained for each of the exposure times. Histograms, representing a distribution of pixel values of the each of image data, are generated for each of the exposure times. Regarding each of the histograms, maximum effective values are obtained. A first histogram, in which the maximum effective value is the greatest, is selected. The optimum exposure time is calculated, based on the maximum effective value (Hr2D) of the first histogram and the maximum effective value (Hr1D) of the second histogram which corresponds to image data, obtained by an exposure time which is subsequently shorter than the exposure time of the first histogram.

Abstract: In a method of preventing doming phenomena, luminance histogram distribution values are obtained (10) from a luminance signal, the various luminance histogram distribution values are processed and normalized (12), the luminance histogram distribution values are processed (16) to correct for at least actual contrast and brightness settings to obtain corrected histogram data, a beam current is predicted (18) from the corrected histogram data, and a correction signal is derived (20) from the predicted beam current and making said correction signal effective in the processing and normalizing step (12).

Abstract: An image processing apparatus includes a photographing condition estimation unit for estimating a photographing condition of the input image on the basis of photometric information of a photometric evaluation unit and focal information of a focal point detection unit; a Y/C separation unit for separating the input image into a luminance signal and a color difference signal; a luminance correction unit for extracting an edge from the luminance signal and correcting the luminance signal by a gradation conversion curve obtained by weighting depending on the photographing condition; a color difference correction unit for performing correction on the color difference signal on the basis of luminance signals obtained before and after the gradation correction and a theoretical limit characteristic of color reproduction; a skin color correction unit for performing skin color correction or the like depending on the photographing condition; a Y/C synthesis unit for synthesizing the luminance signal and the color differ

Abstract: A system and method for adjusting the color of a scanned image includes obtaining image data for the scanned image, generating an output image from the scanned image, and obtaining image data for the output image. The differences between the image data of the scanned image and the image data of the output image are determined, coefficients are generated from the determined differences. The image data of the scanned image is then adjusted based on the generated coefficients.

Abstract: A color marking system includes a control system for maintaining an accurate representation for approximating color space transformation comprising a set of piecewise homeomorphisms. The homeomorphisms and parametric models are selectively adjustable in accordance with printer/display calibrating data. Preferably the homeomorphisms comprise corresponding tetrahedra with domain and co-domain color spaces. If error above a selected level is detected, the tetrahedra are adjusted by calculating new locations for their vertices having a consequence of recomputation of model parameters and converging parametric model performance in accordance with a predetermined objective of the system. An inverse of the model is used for feedforward control of the marking system.

Abstract: No compression is applied to saturation data up to a value thereof slightly lower than a boundary of saturation values capable of being reproduced by an output unit. Data representing saturation equal to or greater than a threshold value is subjected to non-linear compression so as to render the data reproducible by the output unit. Since only the necessary saturation is compressed, an image having a saturation close to the saturation represented by the original input saturation data can be reproduced in the output unit.

Abstract: A luminance gradation correcting apparatus which can properly correct the gradation of a luminance level even if a size of actual image portion of an image differs from a size of image.

Abstract: An image processing method, an image processing system and a recording medium capable of reproducing images in colors which are close to those memorized by man including a process to create a histogram of an original image, a process to adequately locate a highlight point on the histogram by comparing peaks of the histogram and setting image processing conditions dependently on a shape of a selected peak.

Abstract: R, G, B signals outputted from a digital camera or a color scanner are converted into calorimetric signals by a colorimetric converter having a colorimetric conversion matrix and a calorimetric conversion table. Colorimetric signals are processed for setup by a calorimetric setup unit. Colorimetric signals processed for setup are converted by a cmyk converter into c, m, y, k signals that are half tone dot % signals for being supplied to an image output unit such as a film producing device, a color printer, or the like.

Abstract: The present invention discloses the detection of faces in digital images. Rather than subjecting the entire image (1) to computationally intensive face detection analysis, the image is instead segmented into regions (2) each of which has a substantially homogeneous color. Only those regions (2) having a predominantly skin color are then subjected to the face detection analysis. Preferably the face detection analysis is independent of facial color.

Abstract: A gradation correcting apparatus which is capable of preventing a luminance distribution from excessively extending over the dynamic range to accomplish an optimal gradation correction in accordance with the partiality of the luminance distribution of a particular video signal. A corrected luminance level is created for each of a plurality of luminance levels based on the frequency data in a luminance distribution such that the luminance distribution of the input luminance signal extends over a predetermined dynamic range, and is stored in an extension correcting table memory. A variance value is calculated for the luminance distribution in accordance with the frequency data to set a mixture ratio based on the variance value. Each of the plurality of luminance levels and the corrected luminance level in the extension correcting table memory corresponding thereto are mixed in the mixture ratio.

Abstract: A method for detecting the illumination color to store the color-compensated image considering the light effect of illumination environments on photographing with a color image input apparatus such as a video camera. The present invention provides a method for finding highlight areas appearing on the objects in the image and obtaining the illumination color resulting from the analysis of the color of the pixels included in those highlight areas. The chromaticity coordinates of the pixels in a highlight area occurring on the uniformly colored object are distributed between the body color of the object and the illumination color. The distribution of those chromaticity coordinates is referred to as the color transition band. The straight lines are approximated on the chromaticity diagram using these color transition bands obtained from highlight areas presenting several uniformly colored objects. The illumination color is determined as the average of the intersections between the lines.

Abstract: An image data processing apparatus includes a determining section for determining whether input image data supplied is a color image mode or monochrome image mode, a histogram forming section for forming a histogram corresponding to the input image data, a reference value calculating section for calculating a first reference value for density adjustment for the color image mode corresponding to the histogram, a reference value converting section for converting the first reference value into a second reference value for the monochrome image mode, and a density adjusting section for adjusting the density of the input image data by using the first reference value when the determining section determines that the input image data is the color image mode and using the second reference value when the determining section determines that the input image data is the monochrome image mode.

Abstract: Software of a simple configuration checks whether an original image to be corrected is an image picture, and an image correction process based upon a formed histogram of the original image is not performed for an image different from the image picture. An image processing condition is set in accordance with the formed histogram to perform the image correction process for the original image. An image processing method judges from a shape of the formed histogram whether the original image is an image picture, and does not perform not perform the image correction process for the original image if it is judged that the original image is not an image picture.

Abstract: A method that creates a high detail reproduction of an image that closely matches the color and tone of an existing photograph. Scanning the original negative of the image retrieves the image detail. Scanning an existing photograph of the image retrieves the color and tone information. The image detail information and the color and tone information are then combined to create a high detail reproduction of the image that closely matches the color and tone of the existing photograph.

Abstract: In order to enable satisfactory image processing according to a characteristic of an original image, image data representing an original image is input; it is judged whether or not the value of a saturation component of the image data is larger than a predetermined value; if the value of the saturation component of the image data is larger than the predetermined value, a histogram of the original image is formed except the image data; a color processing condition is set on the basis of the formed histogram; and color processing is performed to the original image on the basis of the set color processing condition.

Abstract: A method and apparatus enhance a color or grayscale raster image in a printer by identifying a working pixel in the raster image for anti-aliasing, and then modifying luminance data of the working pixel in a luminance chrominance color space such that an anti-aliasing effect is achieved relative to the raster image. The luminance component of the raster image data is converted to a binary format to identify the working pixel using RET template matching. The luminance data of the working pixel is modified by utilizing luminance data of adjacent pixels to produce a new luminance value which is then assigned to the working pixel. One of the adjacent pixels defines an edge of the object being anti-aliased in the raster image, and the other of the adjacent pixels defines an edge of a region in the raster image that is adjacent the object.

Abstract: An image processing apparatus which processes a plurality of supplied color image signals and outputs the processed signals to an image forming apparatus.

Abstract: Digital image data corresponding to an original read in by a CCD is stored in a page memory in pixel units, and a CPU reads the stored image data and creates a histogram. For an original having many high-density portions, an image is formed using a LOG conversion table which generates density data that enables reproduction of the tonality of the high-density portions. For an original which is comparatively faint, an image is formed using a LOG conversion table which generates density data that assures tone reproduction up to the maximum density of the original even if high-density portions cannot be reproduced. As a result, tone reproduction suited to the original image can be realized at all times.

Abstract: The present invention generally relates to a digital scanner for scanning images and is directed to a method and apparatus for accurately scanning documents and for processing digital data to generate digital images as accurately as possible. The scanning system described in this application provides recommended settings for image mode and image parameters to assist the user in adjusting the settings to match the original document. The image data is analyzed to determine the optimum settings.

Abstract: A method and apparatus are described for detecting photocopier tracking signatures placed on documents produced by color photocopiers. The apparatus includes an input terminal that supplies digital image data representing an input document produced by a color photocopier. The digital image data includes a plurality of pixel values grouped together to form a plurality of color separations that represent the input document. The apparatus also includes an image processing unit that generates an output image based on the digital image data. The image processing unit generates the output image based on differences between corresponding pixel values of at least two of the plurality of color separations. The apparatus further includes an output terminal for displaying the output image to view the photocopier tracking signature. Color differences can be detected by combining two or more of the color separations into a resulting monochromatic image and then enhancing the resulting color differences.

Abstract: An image enhancing apparatus is provided and includes a histogram equalizer and a compensating circuit. The histogram equalizer equalizes an input image, which is expressed by a predetermined number of gray levels, and outputs a corresponding equalized output image. The compensating circuit determines an input mean value corresponding to the input image and an output mean value corresponding to the output image and calculates a mean difference based on the input and output mean values. Then, the compensating circuit adjusts the equalized output image based on the mean difference to prevent a reduction in the mean brightness of the equalized output image. As a result, a reduction in the mean brightness of a light screen can be avoided and any deterioration of the output signal caused by the histogram equalization can be prevented to provide a stable image display. In-addition, a method performed by the apparatus is also provided.

Abstract: An image forming apparatus comprising a scanner for reading an original and outputting image data for the original including color information and an image forming mechanism for forming an image either in black and white or in color according to the color information contained in the image data.

Abstract: An image processing device determines whether or not a scanned image is copy-prohibited based on comparisons between a histogram of the brightness of the pre-stored copy-prohibited material such as paper currency and a histogram of the scanned image, and/or between the size of the copy-prohibited material and the size of the scanned image. A document is scanned by a scanning unit, and the brightness histogram of the scanned image is generated by a histogram generating unit. This histogram is then used by a copy-prohibited determining unit to determine whether or not to prohibit copying.