Abstract: A spatio-temporal joint filter and a spatial joint filter for noise reduction are disclosed. The spatio-temporal joint filter includes a spatial joint filter including the first and second sub filters having different characteristics and includes a temporal joint filter. When the present invention is adequately used, an edge/detail region of an image is well preserved, an aggressive noise reduction is performed on a flat region, and the temporal flicker problems are eliminated. Additionally, it has an intrinsic motion compensation effect by using the spatio-temporal correlation between the adjacent frames.

Abstract: A system and method for handling duplex documents by exploiting bleed-through of the image on the back side of a document. The images of the back sides and front sides of documents are associated with one another to assure correct output in copying, faxing, scanning, etc. This increases reliability, eases recovery from errors including paper jams. Improved document handling capabilities also include avoiding twice duplicated and skipped pages and correcting page orientation errors.

Abstract: A method, system, and software are disclosed for improving the quality of a signal. A signal is converted to a digital representation and then segregated into separate data sets based on one or more properties of the data sets. Data sets exhibiting relatively more information associated with a selected property are designated as shepherd artifacts, and data sets exhibiting relatively less information associated with a selected property are designated as sheep artifacts. A representative shepherd artifact is then used to guide a representative sheep artifact, resulting in a guided artifact with enhanced signal properties. This process may be repeated for other categories of signal properties. The resulting guided artifacts may then be combined to form a processed signal with one or more enhanced properties having increased quality. The present invention finds particular application in photography and digital film processing, whereby the illustrated method may be used to improve image quality.

Abstract: Disclosed is an image sensing apparatus having a function of removing a dark current noise component of an image sensor. This image sensing apparatus includes an image sensor such as a CCD, at least two noise component storage areas, a CPU for controlling an operation of writing a noise component of one frame generated by the image sensor into a noise component storage area selected from the at least two noise component storage areas, and a subtracter for correcting an object image photographed by the image sensor, on the basis of the noise component stored in one of the at least two noise component storage areas.

Abstract: A system and method that provided for preview scanning a document and generating a preview scan image, determining a document type based on the preview scan image, mapping the document type to a predetermined workflow, scanning the document to capture an image of the document, and executing the workflow.

Abstract: The color image processing apparatus of the present invention selects, on the basis of a moving average number n of pixels calculated by a predetermined numerical formula with respect to any notable pixel i, n number of reference pixels j located before and after the notable pixel i, and calculates an absolute value of a difference between an output of respective of the selected reference pixels j and that of the notable pixel i. Then, a moving average processing is executed by using only some reference pixels j of which the absolute value of the difference between each of their output levels and the output level of the notable pixel i is smaller than a threshold value.

Abstract: Disclosed is a method, system, and program for modifying raster pel data according to different types of filtering operations. At least two tables are maintained in memory. At least two of the tables provide output pel values for at least two different types of filtering operations based on input pet values. A plurality of pets are read from raster data for a print job. A determination is made of an entry in one table based on the plurality of read pels to determine at least one output pet value that accomplishes the filtering operation associated with the table. At least two of the tables may be used in the same page of raster data to perform the different filtering operations associated with the at least two tables used within one page. The at least one output pel value is used to generate a pulse to control a printer apparatus.

Abstract: An image information reading apparatus that can obtain high quality images without an effect of noise and a photographing condition or the like is realized even in the case where a low-bit A/D converter is used. The apparatus comprises control means for switching between pre-reading to main reading, characteristic determination means for determining, by analyzing an electric signal obtained by the pre-reading, a normalization processing characteristic used in normalization processing on an electric signal obtained by the main reading, and normalization processing means for carrying out the normalization processing on the electric signal in the main reading according to the determined normalization processing characteristic. The characteristic determination means analyzes image data by using a cumulative histogram of pre-reading data, and determines the normalization processing characteristic so that an image represented by the image data has adequate density and contrast.

Abstract: A technique for reducing noise in pixel images includes shrinking a first image and a second, related, image, and processing the first shrunken image with a novel segmentation-based filtering technique which utilizes image data from the second shrunken image to help identify structures within the image. After the structures are identified, the first shrunken image is differentially processed to reduce image noise. After processing, the first shrunken image is enlarged to the dimensions of the initial data, subsequently processed if necessary and the final image is displayed or analyzed. The resulting technique is versatile and provides greatly improved computational efficiency while maintaining image quality and robustness.

Abstract: An image processing apparatus which eliminates noise which occurs due to the influence of output from a parallel bus drive circuit added to an output final stage circuit of signal processor or the like. A delay circuit 110 which delays a video signal is inserted into a VTR signal processor such that a data transition point of particular bit in a bit array indicating horizontal-directional start and end positions of video signal data, added during a horizontal retrace period of a digital recording format video signal, does not overlap with a period for sampling a feedthrough period and a photoelectric conversion signal period in a correlated double sampling circuit.

Abstract: A technique for reducing noise in pixel images includes modifying initial image data to prevent subsequent image data loss, shrinking the modified image, processing the shrunken image with known segmentation-based filtering techniques which identify and differentially processing structures within the image. After processing, the shrunken image is enlarged to the dimensions of the initial data and subsequently processed to correct intensity irregularities and to preserve CT numbers. The resulting technique is versatile and provides greatly improved computational efficiency while maintaining image quality, allowing for dose reduction during imaging.

Abstract: An image reading-out apparatus including a background level detecting circuit, an analog-to-digital converter, and a black-shading compensation circuit. The background level detecting circuit is configured to detect the background level of the original document from the image data. The analog-to-digital converter is configured to remove an influence due to the color of the background on the original document from the image data and configured to perform the analog-to-digital conversion of the image data in accordance with the detected background level. The black-shading compensation circuit is configured to perform black-shading compensation of the image data after the analog-to-digital conversion.

Abstract: A document-backing surface for reducing show-through when a duplex-printed document is scanned but without producing undesirable artifacts. The document-backing surface has a plurality of first and second light-absorbing surfaces, and a plurality of specularly reflective surfaces partially covering each of the second light-absorbing surfaces. The first specularly reflective surfaces are oriented to reflect light from a scanner lamp to a scanner sensor. In an alternate embodiment, the document-backing surface is partially covered by a specularly reflective surface oriented to reflect light from the scanner lamp to the scanner lens. In another embodiment, the document-backing surface has a set of teeth, each of which has light-absorptive first and second tooth surfaces and a specularly reflective surface partially covering each second tooth surface. In addition, the present invention is directed to a method for using a document-backing surface.

Abstract: A method of noise removal from a digital image, especially moiré noise, comprising providing a three-dimensional representation of a at least one image color channel as a surface over the plane of the image, creating a virtual surface patch, placing the surface patch against topography in the three-dimensional surface mapping of the image so that the virtual surface patch intersects topography of the three-dimensional surface with respect to at least some pixels of the image surface region, adjusting the height, tilt and curvature of the surface patch with respect the image surface in order to optimally represent the surface, then estimating a palliative value for the image surface for at least one pixel within the area of the surface patch from the adjustment of the surface patch, and replacing the value of the at least one pixel in the at least one image color channel with the palliative value.

Abstract: The invention relates to a method for relocating objects in images. An object reference is correlated with image values. When the object is partially covered in the image, the image values which are located within the covered area in the image are replaced by grey scale values of the object before the correlation is carried out. A system for relocating objects in images is provided with a camera for filming the image, an imagery storage unit for storing an object reference and an imagery processor for replacing grey scale values which are located within the covered area, whereby said grey scale values are replaced by grey scale values of the object reference. The inventive system is also provided with a correlation unit which correlates the image with the object reference, whereby the image has been changed by the imagery processor.

Abstract: An image processing system includes an image collector and a light falloff correction system. The light falloff correction system comprises a polar transformer that converts an image into radial traces and a falloff fitter that fits the radial traces to a model of falloff to determine a light falloff correction for the image.

Abstract: In a method of correcting defects in image data comprising an array of pixels, the intensity of pixels of the image data in each side of the defect is sampled (5), differences between the samples intensities are calculated (6) to generate intensity difference signals (D1-D4) indicative of intensity differences across and on respective sides of the defect, and the defect is corrected (7-11) in dependence on the intensity difference signals (D1-D4). Preferably, depending on the intensity difference signals (D1-D4) either an average correction technique or no defect pixel correction is used, the average correction technique being used if the intensity difference signals do not exceed a predetermined level value (L1,L2).

Abstract: CCD1 as an image reading part reads a copy at the upstream and downstream of reading positions, and image data B and A at each of the reading positions are obtained from an output delay circuit and a shading correction circuit, respectively. A streak detector 8 compares the image data A with B, and outputs black streak detecting data indicating that the image data A contains black streaky noises, when the image data is not coincident in succession as to a plurality of pixels arrayed in the sub-scanning direction. A streak eliminator normally outputs the image data A, but it outputs the image data B instead of the image data A with regard to the pixels from which the black streak detecting data containing the noise is outputted. The image data reading device of present invention being thus constructed, the device is able to accurately detect streaky noises by adhesion of thrashes to the reading unit, even if there are speed variations in the copy feeding.

Abstract: A method for estimating a noise characteristic value for a plurality of digital images that are affected by a common noise source includes receiving a plurality of source digital images that are affected by a common noise source, each source digital image including a plurality of pixels; calculating a total number of pixels included in the source digital images; and receiving a predetermined target number of noise estimates to be calculated for the source digital images. The method also includes using the total number of pixels and the predetermined target number of noise estimates to calculate one or more pixel sampling parameters for the source digital images; using the source digital images and the one or more pixel sampling parameters to calculate a predetermined number of noise estimates; and using the noise estimates to calculate a noise characteristic value for the source digital images.

Abstract: An image processing method and apparatus for forming a mosaic image by combining a plurality of material images, dividing a first image that is the basis of the mosaic image into a plurality of tile areas, comparing each tile area with each of the material images, selecting a material image that most resembles the tile area in terms of color or luminance and pasting this material image to the tile area, thereby creating a mosaic image.

Abstract: A mono-color signal converter extracts a mono-color signal in terms of the CMY system from RGB signals. A histogram generator generates a density histogram based on the density of the pixels in the digital image. At the same time, based on the thresholds determined previously, determination areas for the background density and maximum density are formed. A density class extracting portion extracts the density class of the background density and the density class of the maximum density. Based on the result from the density class extracting portion, a density correction curve generator generates a density correction curve. When the density correction curve needs to be adjusted as desired, the starting point and end point of the density correction curve are renewed through a first correction value and second correction value setting portion. A signal converter converts the mono-color signal into the K-signal.

Abstract: A digitizer having a dual exposure technique is combined with an associated LUT for each exposure. Each LUT may have a transfer function including a logarithmic operator resulting in a digitized image with improved photometric resolution and increased dynamic range. A digitizer utilizing multiple exposures at approximately equal exposure time intervals provides a noise reduction for lower optical density portions of the data medium further contributing to increased dynamic range. Associated methods are also provided.

Abstract: In a contour correcting circuit that generates, on the basis of respective signals for a plurality of pixels including the pixel to be corrected at the center and arranged in a particular direction, a contour correction signal for the pixel to be corrected, there are provided contour component production means for producing a contour component for the pixel to be corrected depending on the gradient of the change among the respective signals for the plurality of pixels arranged in the particular direction; gain calculation means for calculating, on the basis of the level difference between the signal for the pixel to be corrected and the signal for the pixel adjacent in the particular direction to the pixel to be corrected, such a gain for correction that the larger the level difference is, the smaller the gain becomes; multiplication means for multiplying the contour component produced by the contour component production means by the gain for correction calculated by the gain calculation means; and addition m

Abstract: In order to reuse print sheets, a region on a printed sheet where old information is printed is detected and a region corresponding to the region where the old information is printed is identified as an erasing region. A pattern corresponding to the erasing region is printed on the erasing region with erasing ink or toner, which has a different color from a color of printing ink or toner, whereby the printed old information is erased. Then, new information is printed on the print sheet, from which the old information has been erased, by use of the printing ink or toner.

Abstract: An image enhancement method. In the first stage, an image described in first image format is received. Then, each pixel is assessed with respect to its location on the edge of the image, and the value of the pixel in second image format is assessed with respect to its falling within the range of skin tones. A first smooth filter mask is dynamically generated if the pixel is not on the edge and the value does not fall into the range of skin tones, and a smooth process is performed on the pixel according to the first smooth filter mask. In the second stage, a second smooth filter mask is dynamically generated for each pixel in the image, and a general smooth process is performed on the pixel according to the second smooth filter mask.

Abstract: An edge enhancement method and an edge enhancement apparatus in digital image scalar-up circuit are provided. A band-pass filtering process is performed to an input image pixel in multiple directions to generate multiple sum-of-border values which are summed up to generate an overall sum-of-border value. A first gain and a second gain are provided according to the overall sum-of-border value. A high-pass filtering process and a low-pass filtering process are performed to the input image pixel to obtain border and plain components which are multiplied by the first gain and second gain, respectively. The gained border component and plain component are summed and added to the original pixel to obtain a new pixel.

Abstract: A method and apparatus for enhancing the contrast of an image, where pixels of the image having a brightness less than a mean brightness of the image are transformed in accordance with a first straight-line function, and pixels having a brightness greater than the mean brightness of the image are transformed in accordance with a second straight-line function. Variable slope factors of the two straight-line functions are determined by an analysis of the brightness distribution of the transformed output image. The pixels, thus transformed, produce the contrast-enhanced output image.

Abstract: A vertical black line removal system (VBLR) is adapted to remove unwanted vertical lines produced on scanned document images by dust or other particles on the imaging apparatus. The VBLR system, placed in a document scanner after the binarization equipment, creates a stored histogram table including the difference values of “1” or “0” for the first and second image data. A vertical black line search processor compares each histogram value in the histogram table with a predetermined threshold value such that when the histogram value is greater than the threshold value the histogram value and the image address indicating the location of defect are stored in memory.

Abstract: A process for transforming digital source image data to provide a desired image look at the end of an imaging step chain is described comprising: defining desired values for at least two image look parameters associated with the desired image look; sensing the values of the defined image look parameters for the digital source image data; and modifying the digital source image data to provide digital output image data with at least one image look parameter value closer to the defined image look parameter value associated with the desired image look. The desired image look parameters may be defined with respect to an image to be displayed after further processing of the digital output image data downstream of the modifying step, information may be provided on the characteristics of the downstream processing, and the modifying step may be designed to compensate for effects of the downstream processing on the desired image look parameters.

Abstract: A method and system for processing an image based on noise appearance in the image, includes the steps of and means for: forming a noise table representing noise magnitude vs. intensity of the image; providing a plurality of potential image processing paths, each path having at least one image transform; modifying the noise table according to the image transform(s) in the at least one image processing path to produce an output noise table, generating a noise metric from the output noise table, said noise metric representing the noise appearance of the image processed by the at least one image processing path; selecting one of the plurality of potential image processing paths based on the noise metric; and applying the selected image processing path to the image.

Abstract: A method for post-processing compressed image data for reducing blocking artifacts is suggested, in which a set of primary image data (PID) is decomposed into data sets (IID1, IID2) containing the fine structure of the image with structure being smaller than the blocking artifacts and without the blocking artifacts and structures being larger than or comparable to the blocking artifacts as well as the blocking artifacts, respectively. In the decomposition of the primary image data (PID) a non-linear filtering process (F1) is involved. After decomposition of the primary image data (PID) a filtering process (F3) can be applied to the set of intermediate image data (IID2) containing larger details of the image as well as the blocking artifacts. Therefore, in the process of filtering out the blocking artifacts, the fine structure of the image is not influenced.

Abstract: The present invention is directed toward correcting a corrupted image of an object to remove the effects of smearing or misdirected flux in the image, wherein the image comprises one or more dimensions and has a plurality of image elements. The method of the present invention comprises the steps of: a) sampling portions of the image of the object at unequal intervals, the intervals being selected to effect an implicit weighting of the samples corresponding to a predetermined weighting function; b) summing the implicitly weighted samples to create an approximation to a weighted integral; c) repeating steps a)-b) to compute weighted integrals associated with each of the plurality of image elements thereby to obtain a correction to the image. The present invention is also implemented as a computer readable medium for controlling a computer to implement the steps of the method and in apparatus form.

Abstract: An object of this invention is to efficiently attain noise removal. In order to achieve the object, the discrete wavelet transforms of an input image are computed to output wavelet coefficients of respective subbands (S301). Appropriate threshold values are respectively set for subbands HL, LH, and HH indicating high-frequency components (S302a, S302b, S302c). The wavelet coefficients of the subbands HL, LH, and HH then undergo threshold value processes using the set threshold values for the respective subbands (S303a, S303b, S303c). Pixels to be processed in a coefficient conversion process are determined based on the threshold value processing results of the respective subbands (S304). The wavelet coefficients of the respective subbands corresponding to the pixels to be processed determined in step S304 undergo coefficient conversion (S305), and the converted transformation coefficients undergo inverse discrete wavelet transformation, thus reconstructing and outputting a noise-removed image (S306).

Abstract: In the retrieval of images that resemble a target image from a plurality of images, the image feature quantity of the target image is calculated when the target image is specified. The feature quantity is calculated upon removing an unnecessary area from the specified target image, and retrieval of resembling images is performed using the feature quantity that has been calculated. The unnecessary area is determined automatically based upon a change in luminance in directions vertically and horizontally of the periphery of the target image. Thus, the calculation of feature quantities from which unnecessary portions in an image have been eliminated can be executed with ease and more effective retrieval of resembling images can be carried out.

Abstract: An image recorder performs a first distortion correction at the resolution of an input image and a second distortion correction at the resolution of a recording head. The first distortion correction is performed by setting an angle difference between a write angle and a read angle to and from address space in a buffer memory (BM) to be equal to an inclination angle of scanning lines with respect to a main scanning direction. The second distortion correction is performed by shifting image data obtained by the first distortion correction in a sub-scanning direction by an amount responsive to the inclination angle. The smallest unit of the amount is one pixel unit (P). More specifically, image data is shifted by the width of one pixel (D) in blocks for memory access, and then for output of a gradient value for each pixel (D), it is further shifted by the width of one pixel unit (P) in sub-blocks which are obtained by dividing each block.

Abstract: A method of correcting illumination variation in a scanned image of a non-planar original object, such as an open book, includes scanning at least a portion of the book in order to produce scanned image data. Illumination variation data is extracted from the scanned image data and used to derive a plurality of illumination compensation values. The scanned image data is then compensated or scaled in accordance with the illumination compensation values. Illumination data is acquired through a sampling window having a long and thin geometry. From the data acquired via the sampling window, foreground and background illumination distributions are defined. From the foreground and background illuminations, high and low threshold values are determined in order to calculate a set of reference or compensation values. A tone reproduction curve is generated in order to map the scanned data, thus normalizing the illumination variation. Alternately, an illumination gain factor is employed in the compensation.

Abstract: A method for controlling an image reading apparatus (100) performs an auto focus process for adjusting the focus on a medium (300) surface and a reading process for reading an image on the medium (300) at the focus adjusted by the auto focus process. During the auto focus process, a difference processing unit (5) calculates differences between adjacent picture elements in image data read from the medium (300), an averaging processing unit (6) averages the differences, and a midpoint processing unit (7) slices characteristic data obtained from the averaging processing into a plurality of region to determine the midpoint in each region, so that the focal point can be calculated.

Abstract: A digital image processing apparatus capable of high-quality reproduction in which a black isolation point does not lie scattered even for a manuscript document having a colored background.

Abstract: The output voltage of a pixel is held as a reference signal output voltage in a reference signal holding capacitor connected to a positive input terminal of a second subtractor by lowering the potential of a reset voltage to that of a calibration voltage and by activating a reset pulse and a reference-signal-calibrating pulse. Then, the reference signal output voltage is output from the second subtractor. And a corrected reference signal output voltage, obtained by subtracting the reference signal output voltage from a no signal output voltage, is held in a corrected reference signal holding capacitor. Moreover, a divider divides a corrected original signal output voltage, which is held in a corrected original signal holding capacitor, by the corrected reference signal output voltage, which is held in the corrected reference signal holding capacitor.

Abstract: An image input device identifies what part of the optical input system needs cleaning when there is dust or other foreign matter in the optical input system. This image input device has an image noise position detector for capturing image data from a scanner, and detecting the main scanning address of noise information corresponding to image noise present in the image data; a focus calculator for calculating focus information around the main scanning address detected by the image noise position detector; focus information storage for storing focus information for each subscanning line; and a foreign matter position determining circuit for determining the location of foreign matter on the scanner based on the focus information stored in the focus information storage.

Abstract: To realize low noise and chip area reduction, a signal processing apparatus including a signal source, an arithmetic circuit for performing an arithmetic operation, and a non-inverting output circuit for outputting a signal from the arithmetic circuit which includes at least a transfer circuit for transferring a signal from the signal source to the non-inverting output circuit, and a difference signal formation circuit for forming a difference signal obtained by subtracting a signal from the non-inverting output circuit from the signal from the signal source.

Abstract: A method and apparatus for processing an input image to remove color marks from the input image. The method includes the steps of detecting RGB entries in a CMS table that are not on a gray diagonal proximity. Next, the method changes output space values for the RGB entries to a shade of gray. Finally, the method converts the input image to an output image by referencing the CMS table.

Abstract: A color image processing provides a thin-line enhancement module for a color image for finding and keeping thin lines in the color image. A boundary enhancement module is provided for finding and keeping the boundary in the color image. A de-background module is provided for removing noise pixels from the white background. The color image is processed to avoid missing and/or twisting the thin lines, boundary, background, and texts in the color image after the scanning procedure.

Abstract: An input picture signal having noise added through a transmission path or the like is supplied. Noise is removed from the input picture by a class categorizing adaptive process in which predictive coefficients are pre-learnt and decided for each class. A class corresponding to a noise component contained in the input picture is decided. Predictive coefficients of the class and the values of pixels of frames containing a considered pixel of the input picture signal are linearly combined. Thus, predictive pixel values are generated, which are free of noise. When motion of a considered pixel is detected and pixels that are used to decide a class and pixels that are used for a predictive calculation are compensated corresponding to the motion, noise accurately corresponding to a noise component can be removed from the input picture signal.

Abstract: A processed image signal is obtained from an original image signal representing an original image by carrying out on the original image signal an image processing based on a signal representing information on a high frequency component of the original image signal. Band-limited image signals are made from the original image signal, and a signal representing information on a high frequency component of the original image signal is obtained from the band-limited image signals on the basis of a predetermined transformation function. The image processing is carried out on the original image signal on the basis of the signal representing information on a high frequency component of the original image signal.

Abstract: There is provided an image reading apparatus that is capable increasing the detection accuracy for dust, scratches, dirt, and the like. Sixty-four lines of sampling points on a reference standard white plate are read, shading correction and averaging are carried out the read image data to suppress random noise components in the image data, the data is then stored in a sampling memory, and dust detection is carried out on the data stored in the sampling memory. Alternatively, shading correction and dust detection are carried out on image data that has been subjected to linear interpolation. It is thus possible to increase the accuracy of detection of dust, scratches, dirt, and the like while ensuring that shading correction is performed at high speed.

Abstract: A method and apparatus for detecting typing errors of critical fixed series of characters (digits) by using at least one redundant parity digit. The invention detects the most common typing errors that involve both permutations and incorrect striking of adjacent characters during data entry via a keyboard of an electronic apparatus. The method provides warning to the data input operator when incorrect data entry occurs and optionally automatically suspends entry thereof.

Abstract: A first signal and a second signal are obtained using a first and second image sensors, respectively. The first signal and the second signal are converted from analog to digital form. The first signal and the second signal are then averaged to improve the signal to noise ratio of the resulting signal. The first signal may be obtained using a channel corresponding to a first channel. The second signal may be obtained using a channel corresponding to a second channel. Further, a third signal may also be obtained using a channel corresponding to a third channel. Then, the first, second, and third signals may be averaged to generate an averaged signal.

Abstract: A device and a method for image processing make it possible to significantly improve the contrast and the sharpness of the whole image, in comparison with the ordinary. By amplifying the portions other than the edges, while conserving the edges with the pixel values which change abruptly out of input image data, it is possible to enhance and display the portions other than the edges, and so it is possible to significantly improve the contrast and the sharpness of the whole image, in comparison with the ordinary.

Abstract: An original image signal made up of a plurality of image signal components each representing a pixel of an original image is processed to suppress the granularity of the original image and enhance the sharpness of the original image, and a final processed image signal is obtained. Processing for suppressing granularity and processing for enhancing sharpness are carried out separately on the original image signal to obtain a granularity-suppressed image signal and a sharpness-enhanced image signal.