Abstract: A method for detecting an image area in a digital image includes identifying in the digital image a first image region indicative of a background area and a second image region indicative of the image area, computing gradient values using the pixel values of the digital image, defining a list of strokes based on the gradient values, merging the list of strokes, defining a list of corners using the list of strokes, and defining an image area rectangle delimiting the image area using the list of corners and the list of strokes. The image area rectangle can be used to define a binding box for extracting the image area from the digital image. The method enables the automatic detection of multiple image areas in a digital image. Moreover, the method implements a robust algorithm for image area detection such that even imperfect image areas can be detected without errors.

Abstract: A light source is turned off (S101), incidence of light on a line sensor is shut off, and the output value of an electric signal output from each of pixels of the line sensor (S102). Since the output value is detected 128 times (S103), random noise can be reduced equal to or less than the variation in the output values for each pixel of the line sensor. The output values detected by a detection section are added up by an average value difference calculation section (S104). The sum total of the output values is divided by the number of detection times (S105) to calculate the average value of the output values (S106). The average value difference calculation section calculates the difference between a setup value and the average value as an average value difference (S107) and the average value difference is stored in black reference memory for each pixel (S108).

Abstract: A color image processing apparatus having at least patch image output units which output patch image data, based on patch data in a storage area, a patch data extractor which extracts read patch data by reading a patch image formed according to the patch image data, using a color scanner, a patch data processor which estimates the record gradation of patch data, based on the read patch data, and a gradation corrector which corrects a given color image signal, based on the estimated record gradation and patch data. The apparatus provides gradation correction based on gradation estimated from patch data, thus making it possible to reproduce gradation and color well.

Abstract: A method for the automatic reproduction of the colors of an original scene from an original image present as a color negative or diapositive film includes scanning the original image electronically, and storing the RGB color values of the image points as scanned transmissions or scanned densities. In the RGB color space, a gray straight line is determined, which approximates the cloud of points formed by the scanned densities of the image points in an optimum way. The transmissions are corrected by minimum transmission values in each case being subtracted from the scanned transmissions. Then, reconstructed film exposures are determined, whereby, by the gray straight line, film exposure straight lines are constructed that describe the relationship between the logarithmic film exposures and the corrected densities. Following the normalization of the film exposures to a standard image range, the film exposures are transformed into the LAB color space.

Abstract: A method enabling checks on correctness of color signal values and an extracting region, which comprises a region deciding step of deciding an extracting region for each color region of a color chart image, an extracting step of calculating a representative color signal value of the color region, a displaying step of making a display unit display the extracting region along with the color chart image, and a determining step of determining correctness of the representative color signal value on the basis of the extracting region and the color chart image displayed on the display unit. This invention is applied when a color transformation table for a color input device such as a color scanner is created, when gradation maintainability of a color input device such as a color scanner is checked, and when a color transformation table for a color output device such as a color printer is created.

Abstract: There are provided an apparatus and a method for adjusting the color temperature of an input image using metadata corresponding to the color temperature of the input image. The apparatus includes a color temperature calculation unit which receives a predetermined image and calculates the color temperature of the predetermined image, a metadata generation unit which divides a color temperature range into a plurality of color temperature sections and generates metadata using information on a color temperature section to which the color temperature of the predetermined image belongs, and a metadata database which stores the metadata corresponding to the predetermined image and transmits the metadata to a user terminal.

Abstract: A lower-bit replacement means of an information addition means replaces lower 3 bits of an 8-bit image signal with 3 bits of an image area separation signal, and outputs an 8-bit conversion image signal. A lower-bit extraction means of an information extraction means extracts lower 3 bits of the 8-bit conversion image signal and outputs an image area separation signal as additional information. On the other hand, as regards image information, the conversion image signal input to the information extraction means is output as it is, as an image signal.

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: There are disclosed gradation correction curve producing method and apparatus for producing a gradation correction curve for correcting a gradation of an image. Density of monochromatic density patches for C, M, Y is measured to determine a first gradation correction curve, and colorimetry of gray density patches consisting of a combined color of C, M, Y is performed to determine a second gradation correction curve for each monochrome of C, M, Y determined from colorimetry values. A gradation correction curve for each monochrome of C, M, Y for gradation correction is determined using the first gradation correction curve and the second gradation correction curve.

Abstract: Color correction and density correction are performed on an image without changing the gradation of an image. When color correction and density correction are performed on image data whose values for each R, G, B component color (each channel) of each pixel are coded according to predetermined characteristics, the image data is sampled and correction values are calculated. The image data is then converted (104) to image receptor reflectivity data (r, g, b) (converted to values whose relationship with the light intensity values of each pixel is linear). The image data is then further converted to tristimulus values data (X, Y, Z) and color correction and density correction are carried out. The tristimulus values data after correction (X?, Y?, Z?) is then converted to image receptor reflectivity data (r?, g?, b?) and then to image data (R?, G?, B?). Accordingly, color and density corrected image data can be obtained without the gradation of the image being changed.

Abstract: An 8-bit (256 gradient) image is represented using a driver IC of 6-bit (64 gradient) construction to drive a plurality of arrayed optical shutter elements. The image data are divided into 64 gradient sections, synchronized by shift clock signals, and transmitted in four cycles to the shift register. The optical shutter element is not turned OFF at the 64th pulse, but is continuously driven without transmitting to the comparator the standard clock signal of the 64th pulse, which controls the ON time of the optical shutter element. In this way, an image of a higher number of gradient levels can be represented using a driver IC of a low number of bits, thereby providing a solid state scanning type optical recording device which suppresses noise generation by reducing the load on the driver IC when driving at multi-level gradient.

Abstract: An image processing method for image-processing digital image data acquired by a digital camera to enable reproduction of high-quality images includes the steps of computing first characteristic values characterizing colors of an image represented by digital image data, normalizing the digital image data based on the first characteristic values to produce normalized image data, computing from the normalized image data a second characteristic value characterizing density of the image represented by the digital image data, and correcting the normalized image data based on the second characteristic value to produce processed image data. Also provided is an image processing system for carrying out the method.

Abstract: Image processing apparatus comprises an input device; an output device; and a processor coupled to the input and output devices. The processor is adapted to compare the tone range of an image scanned by the input scanner and the tone range provided by the output scanner, and i. if the input tone range falls wholly within the output tone range, to cause the output device to render an absolute reproduction of the image, or ii. if the input tone range overlaps the output tone range, to cause the output device to render a reproduction of the image in which that part of the input tone range falling outside the output tone range has substantially been mapped into the output tone range, providing a pleasing appearance.

Abstract: An image processing method for extracting a characteristic amount of a photographed image from the photographed image obtained by photographing an object, comprises a passing through deleting step of deleting a passing through area from said photographed image, a preparing step of preparing an outside outline of the object from the image from which the passing through area is deleted, and a setting step of setting an area from which the characteristic amount is to be extracted from a shape of the outside outline.

Abstract: Ink ejection/non-ejection from a plurality of ink ejection print elements is controlled by looking up a first table that indicates the correspondence between a plurality of inks and gray scale values of print pixels, and a second table indicating combinations of density distribution patterns of print pixels and ink ejection print elements in correspondence with gray scale values, in accordance with a pixel density pattern and its gray scale value.

Abstract: In the image processing apparatus a matrix selector selects a position matrix for determining the gradation direction. The gradation direction is the direction of a contrast of a gradation at a position of a target pixel and a dispersion matrix for determining a spatial frequency at the position of the target pixel. Further, a pixel interpolator divides the target pixel into still smaller pixels. A table selector selects a conversion table for determining a gradation level of the smaller pixels based on the gradation level of the target pixel, the position matrix and the dispersion matrix.

Abstract: The present invention provides an image signal processor for providing a color image. In this apparatus, an image file reader (51) reads an image data file having appended thereto information indicative of how the color and gradation representation of image data encoded in the standard color space has been adjusted as information for reproducing color and gradation information on the image data. Image data in an appropriate image block and an appropriate correction method are selected by a judgment unit (52), and the image data is corrected by a correction unit (53). The result of correction is provisionally held in a memory (RAM). Image data after corrected is processed by an on-monitor display processing unit (55) for display on a monitor. Also, the image data after corrected is processed by a print-out processing unit (56) for supply to, and print-out by, a printer driver.

Abstract: An image forming apparatus includes: an image forming unit for forming a correcting image for correcting gradations of an output image, on a bearing body; a sensor for measuring reflected light quantity of the correcting image formed on the bearing body; a gradation correcting unit for correcting the gradations of the output image, based on a measurement result of the measured reflected light quantity of the correcting image; and a timing correcting unit for detecting a shift of measurement timing, based on the measurement result by the sensor, and for correcting the detected shift of the measurement timing.

Abstract: An image processing apparatus for generating a wide dynamic range image to enable contrast to be maintained in low luminance image areas and high luminance image areas when the image is displayed by a narrow density range display system having: an image data buffer in which short-time exposure image data is stored; an image area segmenting circuit for fractionating long-time exposure image data into areas of proper and improper exposure; a segmented area image information extracting circuit for segmenting the properly exposed area of the long-time exposure image data on the basis of the segmented information and segmenting the improperly exposed area as a properly exposed area by applying the short-time exposure image data; a gradation correcting circuit for gradation-correcting image data in the properly exposed areas of the long-time exposure and the short-time exposure images which have been segmented by the segmented area image information extracting means, respectively; and an image synthesizer for synth

Abstract: A method and apparatus for improving image quality in a digital imaging device such as a digital video or still camera. A method for improving image quality of the device has steps of providing a digital image signal, and selecting a color corrector based, at least in part, on a signal-to-noise ratio of the digital image signal. The method and apparatus enables the image quality of an electronic output image output by the digital imaging device to be optimized over a wide range of signal values.

Abstract: A main image and a background image are formed using colors each defined by a set of n-valued basic color gradation values each having any one of n possible values (n is an integer equal to or larger than 3) and defining a gradation value of a corresponding one of a predetermined set of basic colors. Different data items representative of candidates for the background image are stored as background image data candidates. Different sets of the basic gradation values corresponding respectively to the background image data candidates are stored as candidates for a main image gradation value set commonly applied to all valid pixels of the main image. One of the background image data candidates is arbitrarily set to a background image data item representative of the background image.

Abstract: An input image represented by a set of input pixel values is color-corrected by locally modifying the input pixel values according to pixel neighborhoods; and determining an output image having a set of output pixel values. Each set of output pixel values equals a non-linear combination of a set of input pixel values and its corresponding set of modified pixel values.

Abstract: In an image forming apparatus having a particular area setting unit for setting an arbitrary area of a document image as a particular area, an image processing unit (scanner/IPU section) receives, when a particular area is specified, image data for the particular area, and generates a plurality of monitor image data having been subjected to image processing by setting a different image quality mode for each particular area, and further an image forming unit (printer section) receives the plurality of monitor image data and forms a plurality of monitor images on the same transfer material by arranging the monitor images at different positions on the transfer material.

Abstract: The method of gradation correction of input image data to be displayed on an image display apparatus converts to logarithmic data first characteristic values which represent the display characteristics inherent in the image display apparatus and second characteristic values which represent the desired gradation to be eventually realized with the image display apparatus, respectively, and optionally interpolating both the logarithmic data, constructs a gradation correction table based on both the logarithmic data of the first characteristic values and the logarithmic data of the second characteristic values and performs gradation correction on the input image data to the image display apparatus using the gradation correction table. The image display system displays on the image display apparatus the thus corrected image data on which the gradation correction is performed by implementing the method.

Abstract: The invention is directed towards method and apparatus for performing local color correction. One embodiment of the invention is a two-part process. The first part derives an image mask from an input image. In some embodiments, the mask is an inverted, low-pass filtered, monochrome version of the input image. The second part combines the derived mask with the input image through a non-linear operation. In some embodiments, the combination operation is a variable exponential function that has the mask values as part of its exponent and the pixel values as part of its base.

Abstract: Corrected values C1, M1, and Y1 corrected in a quasi-grayscale processing section of an image forming device by an error diffusion technique performed for each channel are evaluated in threshold value sections provided for individual channels, so as to determine whether or not they are greater than threshold values. If an overlapping CMY dot formation detector section detects that the density is higher than the threshold value in all of the three channels, a minimum density channel identifying section instructs a first quantized value substitution section and varies the outputs from the threshold value sections, so that the output in the channel with the lowest density has a value that does not represent dot formation. As a result, overlapping dot formation for the three channels is interrupted.

Abstract: A gradation control system includes a device for deriving 2**n decoded data from lower n bits expressing a gradation per dot, a device for grouping the 2**n decoded data with respect to a plurality of dots, to produce 2**n first bit planes, a device for giving to an element a signal of pattern corresponding to each of the first bit planes for a time obtained by adding a time that depends on a decoded value of each of the first bit planes, to an initializing time, a device for grouping, per bit weight, respective bits excluding the lower n bits that express the gradation per dot, to produce a second bit plane, and a device for giving to the element a signal of pattern corresponding to the second bit plane for a time that depends on a weight of the second bit plane.

Abstract: Provided is an image forming apparatus for forming a toner image including: a first light source emitting a beam corresponding to image information; a first photosensitive member; a first developing means for developing a latent image with a first toner; a second light source; a second photosensitive member; and a second developing means for developing a latent image with a second toner, in which the coloring agent contained in the first toner and the coloring agent contained in the second toner are substantially of the same hue, with the content of the coloring agent contained in the second toner being smaller than the content of the coloring agent contained in the first toner, and in which an oscillation wavelength of at least the first light source ranges from 370 to 500 nm. With the image forming apparatus structured as described above, an improvement in terms of granularity is achieved.

Abstract: Print data received from a host computer is divided into five bands, and expansion time required for expanding the print data is estimated. If it is determined based on the estimated expansion time that a print overrun would occur, grayscale depth during the expansion of the print data is reduced by two bits at a time, in the priority sequence of yellow, cyan, then magenta, until it can be determined that a print overrun will not occur.

Abstract: An image for adjusting a tone curve includes an overall tone curve image including a tone curve of dot gains in a predetermined full scale with respect to all input image gradation values of image data, and an enlarged tone curve image including a tone curve of enlarged dot gains in a full scale, smaller than the predetermined full scale, which represent a highlight area of gradations which is part of the entire tone curve. The user can finely adjust and correct the tone curve in the highlight area while viewing the overall tone curve.

Abstract: A tone correction system, method and interface is described in which a digital image is initially filtered to obtain a corresponding locally averaged value for each pixel value of the image. The image is optimally filtered using a cone-type filter having a small filter radius and which favorably weights the center pixel values of the radius. Shadow and highlight values are obtained from selected shadow and highlight functions, respectively, using the locally averaged values. A tone function is derived from each of the shadow an highlight values for each pixel. Each pixel value of the image is then remapped according to its derived shadow and highlight tone functions. The tone corrected image can be reinteratively corrected by adjusting parameters of the shadow and highlight functions and remapping the image data until a desired image quality is achieved.

Abstract: In one embodiment, a print system includes an anticipated ambient lighting selector to allow selection of an anticipated ambient lighting. A rendering module is configured to map a print job into raster data configured to reduce color cast in gray output when displayed under the anticipated ambient lighting.

Abstract: Disclosed is a system of image data conversion, capable of setting conversion characteristics with more ease even for data having mixed image attributes, and of reducing the amount of data and the size of memory required. The conversion system includes processing elements in a processor array, each including at least an input data register, character registers, an attribute register, and a global processor, so that a calculator in each of the processing elements operates to select, and store in the character registers, the data set, xi, yi, and ai, corresponding to attribute data stored in the attribute register, to be conversion processed subsequently according to an expression stored in the global processor.

Abstract: A method includes forming a plurality of test patches in an array of orthogonal rows. The test patches are formed by using at least one printhead in an imaging machine. Each of the test patches is associated with a respective one of a plurality of initial input color values. The array of test patches includes a plurality of rows of varied-input test patches and at least one row of first equivalent-input test patches. A respective output color value of each of the test patches is measured. At least one first mathematical relationship is generated based on the output color values of the at least one row of first equivalent-input test patches. A plurality of adjusted input color values are calculated for respective ones of the varied-input test patches. Each adjusted input color value is calculated based upon the generated at least one first mathematical relationship. A second mathematical relationship is computed between the adjusted input color values and the output color values.

Abstract: A gradation correction curve creation apparatus for creating gradation correction curves for improving color reproducibility in UCR process includes a first gradation correction curve creation section creating a first gradation correction curve based on measured density values and target density values of monochromatic patches, a second gradation correction curve creation section creating a second gradation correction curve 2based on measured calorimetric values and target calorimetric values of gray patches, a start position calculation section calculating start positions on the first and second gradation correction curves at which the gray component in color mixture starts replacement with K through UCR process, and a gradation correction curve combining section creating a third gradation correction curve by smoothly connecting the more shadowed side of the first gradation correction curve than the start position and the more highlighted side of the second gradation correction curve than the start position.

Abstract: In an image forming circuit, a color image forming apparatus using it, and an image forming method according to this invention, the number of LUTs or RAMs which require different settings for four colors is decreased to two from four in the prior art. By alternately using the two LUTs or RAMs, the capacity, power consumption, and cost can be reduced while required performance such as the processing speed is maintained.

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 present invention relates to an image processing apparatus and an image processing method, and it is applicable to a variety of kinds of image processing apparatus such as television receivers, video tape recorders, television cameras, printers, etc., and it makes it possible to correct the gradation of an image avoiding the lowering of partial contrast effectively. In this case, an excessive emphasis of an outline can be avoided.

Abstract: Density correction method capable of performing density correction at high speed with high precision. In a printing apparatus adopting this method, a predetermined test pattern image is printed on a printing medium, the printed test pattern image is optically read by a sensor at first resolution, the quality of the read image is evaluated, based on the evaluation result the printed test pattern image is optically read by the sensor at second resolution higher than the first resolution, and correction data is generated based on the read test pattern image.

Abstract: An image density discrimination chart for discrimination of a density of an image, usable with an image forming apparatus, the image density discriminating charl includes an exposure portion for being overlapped on an image density discrimination pattern printed on a recording material, and exposing an image density discrimination pattern; and a plurality of comparison patterns which have densities different from each other, disposed aroud the exposure portion, which is to be compared with the image density discrimination pattern exposed through the exposure portion

Abstract: Rapid development of silver bromoiodide color negative photographic films and formation of high quality negative images suitable for scanning to produce display images of excellent quality is made possible by a novel developer solution composition and method of development. The solution is characterized by containing, in addition to the color developer compound and conventional photographic developer solution components, a water soluble pyrrolidone polymer, a high concentration of sulfite ion and a low concentration, or the absence of, bromide ion. In the novel method the developer composition contacts the exposed film at elevated temperature, e.g., 40 to 66° C., for a short development time, e.g., 20 to 90 seconds. The developed image has image quality suitable for scanning and digital manipulation to produce a digital record for forming a color display image of high quality.

Abstract: An image processing method for correcting pixel values of each pixel constituting color image data by shifting, in a coordinate system, a mathematical correction function defining correction values for input values.

Abstract: The invention provides an image processing apparatus and an image processing method and can be applied to an image information apparatus such as, for example, a television receiver, a video tape recorder, a television camera and a printer so that the gradation can be corrected while effectively preventing a finally obtained image from partial deterioration of the contrast. An area to which each of image data belongs is discriminated with reference to, for example, a low frequency component of a pixel value, and a correction coefficient is produced for the area. Such correction coefficients are smoothed between successive frames, and the pixel values of the image data are corrected with the smoothed correction coefficients.

Abstract: A method permitting an end user to recalibrate a color reproduction device. The color reproduction device includes a device for converting the native color values of the scanner into a device independent color space, a test target, and the desired values of each patch of the test target. The method includes printing the test target and scanning it with a scanner that forms a part of the color reproduction device. The device compares the desired values with the values obtained from scanning the printed test target to obtain a set of adjustment values to compensate for drift in the output of the color reproduction device. The compensation emphasizes restoration of the overall gray balance of the color reproduction device and can be implemented by modifying the tone reproduction curves or the halftone process used in the color reproduction device.

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 data processing part in a printer controller performs multivalued dither processing whereby image data is processed for images of characters and thin lines with a high definition, and for pictures with a high color gradation, and the image quality deterioration at the boundary region between an edge region and a non-edge region can be avoided. The data processing part performs discrimination of an edge region, a non-edge region, and a boundary region between the edge and non-edge regions. Furthermore, the data processing part performs multivalued dither processing by using a prepared dot distribution type dither matrix for the edge region, a prepared dot concentration type dither matrix for the non-edge region and a prepared dot distribution and concentration mixing type dither matrix for the boundary region.

Abstract: A method is described for enhancing a digital image channel, particularly where the digital image channel is split into pedestal and texture signals that substantially comprise the digital image channel. The method utilizes a predetermined tone scale conversion to enhance the digital image channel. Initially, image values are provided from the pedestal signal corresponding to image pixels from a region of the image. Then, a statistical characteristic of the image pixels in the region is identified, and the predetermined tone scale conversion is normalized for the statistical characteristic in order to generate a normalized tone scale conversion. The normalized tone scale conversion is then performed on a central pixel of the region in order to generate a pedestal signal with enhanced image values; and the pedestal signal with enhanced image values is combined with the texture signal to generate an enhanced digital image channel.

Abstract: A color image processing apparatus using a gradation image recording method by pulse width modulation comprises a pulse width selection table determining section for determining a pulse width selection table for pulse width modulation, a gradation correction table determining section for determining a gradation correction table based on the determined pulse width selection table, a color conversion table determining section for determining a color conversion table based on the determined gradation correction table, and a color image processing section for correcting a given color image signal and outputting the corrected color image signal based on the determined color conversion table, the gradation correction table and the pulse width selection table. Consequently, a color image processing can be carried out more properly by determining each table and performing an image processing operation in order of a degree of freedom.

Abstract: The invention is a method and apparatus for printing images intended to appear to be of solid uniform color and intensity while conserving the amount of image-generating medium used to form the image. The method and apparatus form such images by continually reducing the amount of an image-generating medium deposited in a first portion of the image from a predetermined amount at an outer edge of the portion to a lesser amount at an inner edge of the first portion.

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.