Abstract: What is disclosed is a novel system and method for banding defect detection and analysis in digital imaging systems. The present method utilizes the gray levels of image regions and a collection of sequence of user images to improve the banding analysis. One embodiment hereof includes: segmenting images into regions; determining banding information for each page over a given sequence of images and detecting problem banding defect frequencies; estimating the banding amplitude(s) and average gray levels for each segmented region for each identified banding frequency(ies); and determining, through a process of interpolation, the banding amplitude for the image or sequence of images based on the banding amplitude and average gray levels of each region. Thereafter, notification can be provided to a key operator when the amplitude(s) are expected to exceed pre-determined levels over the course of a production run. The method demonstrates advantages in banding detection over whole-page methods.

Abstract: A reference-signal generating unit generates a reference signal for generating a driving signal to drive other units of the image reading device. A frequency modulating unit modulates frequency of the reference signal, thereby generating a frequency-modulated reference signal. A driving-signal generating unit generates the driving signal from the frequency-modulated reference signal. A photoelectric converting unit converts an incident light into an analog image signal using the driving signal. An AD converting unit converts the analog image signal into a digital image signal. A correcting unit corrects the digital image signal by generating a correction signal for eliminating a noise superimposed on the digital image signal using the frequency-modulated reference signal and adding the correction signal to the digital image signal.

Abstract: The present invention relates to a device and method (100) of generating a depth map for an image using monocular information, the method comprising: generating (110) a first depth map for the image (205), wherein the first depth map corresponds with an estimate of a global depth profile of a scene depicted in the image, generating (120) a second depth map for the image, wherein a depth value associated with a pixel in the second depth map is based on depth values in the first depth map within a region spatially proximate to the pixel and at least one of color and luminance values of the image within the region and generating (130) a third depth map for the image using depth values from the first depth map and the second depth map, the generating scaling a depth difference, such that a difference between a depth value of the third and first depth map is scaled compared to the corresponding difference between a depth value of the second and first depth map.

Abstract: Depth-of-field information is obtained from an image signal input from an external image source according to a predetermined acquisition timing. An image signal processing unit performs an image quality adjustment such that an edge enhancement level in an edge enhancement processing is increased adaptively with increasing depth of field of an image whereby the total quality of the image displayed is improved.

Abstract: An image processing apparatus includes a correcting unit that performs enlarging or reducing correction on an image to be processed by determining an arrangement of pixels that are to be added to or deleted from gradational image data of the image to be processed based on an angle at which the pixels are to be arranged with respect to a horizontal direction of the image to be processed or with respect to a vertical direction of the image to be processed, and a pixel array control unit that changes the angle at which the pixels are arranged based on a test image of the image data to be processed after being corrected by the correcting unit.

Abstract: An image processing apparatus that includes a character recognition component, a determining component and a generating component is provided. The determining component determines, when document data is generated that contains first data representing the document and representing the entity in which the characters are mixed and second data containing character code data of the characters recognized by the character recognition component and representing a character block displaying the characters represented by the character code data, whether to hide the character block represented by the second data behind the entity represented by the first data or to display the character block represented by the second data in front of the entity represented by the first data when the document represented by the document data is displayed, based on lightness or distribution of the lightness of a background region around the characters of the entity or the like.

Abstract: A recording head (16) is operated to form a regular pattern of image swaths on a recording media (17). The regular pattern of image features comprises a first set of image features (60A) that is formed with an imaging parameter set to a first predetermined value and a second set of image features (60B) is formed with an imaging parameter set to a second predetermined value, different from the first predetermined value. Image features in the first set and the second set are arranged on the recording media with a sub-scan spatial frequency equal to a non-integer multiple of a sub-scan spatial frequency of the image swaths. A scanner (40) generates data (47) of the scanned pattern, wherein a first integer multiple of a sampling spatial frequency employed by the scanner is equal to a second integer multiple of the sub-scan spatial frequency of the first set and the second set of image features.

Abstract: In one embodiment, an image reading apparatus has a light source configured with a plurality of light-emitting elements disposed in a row in a main scanning direction that irradiate light toward an original, and a photoelectric conversion element that receives light reflected from the original, an output light amount from the light-emitting elements can be adjusted, and a state of bright spots due to repetition of light-dark in the main scanning direction on a light irradiation face of the original due to the plurality of light-emitting elements is determined, and the output light amount from the light-emitting elements is adjusted based on the determination result of the state of the bright spots.

Abstract: An image processing apparatus includes a binarization section, a determination section and an area setting section. The binarization section binarizes a given image. The determination section determines whether or not a pixel to be determined is effective in accordance with the number of pixels of one value of a binary value in each of determination areas. Each of the determination areas are placed so as not to contain the pixel to be determined in the binarized image and so as not to overlap in a predetermined direction of the pixel to be determined. The area setting section sets an area including the pixel determined effective in the determination section.

Abstract: A printing apparatus, which prints a composite image formed of an enlargement portion and a non-enlargement portion of an original image on a printing medium, includes: an enlargement portion determining section which determines the enlargement portion, of the original image, which is to be enlarged in the composite image; an enlargement rate determining section which determines an enlargement rate of the enlargement portion with respect to the original image; a print data generating section which generates print data for printing the composite image based on image data of the original image, the enlargement portion determined by the enlargement portion determining section, and the enlargement rate determined by the enlargement rate determining section; and a printing mechanism which prints the composite image on the printing medium based on the print data generated by the print data generating section.

Abstract: An image processing apparatus for use with a printed substrate is disclosed. The image processing apparatus comprises an imaging device configured to receive light reflected from a portion of multiple patches of a colorbar on the printed substrate and configured to process color data from the light reflected from the portion of multiple patches of the colorbar.

Abstract: A system and method for creating a three dimensional cross sectional image of an object by the reconstruction of its projections that have been iteratively refined through mathematical transformations and modifications in object space and Fourier space is disclosed. A primary benefit of the method is radiation dose reduction since the invention can produce an image of a desired quality with a fewer number projections than seen with conventional methods.

Abstract: An image processing apparatus includes an obtaining unit, a determination unit, a setting unit, and a processing unit to perform an image edge intensifying processing. The obtaining unit obtains image data by reading a document. The determination unit determines an image edge direction. The setting unit sets an edge intensifying processing intensity based on the image data and a processing intensity determined corresponding to a difference between resolution in a main scanning direction and resolution in a sub-scanning direction. The processing unit performs the image edge intensifying processing according to the set intensity. In response to the resolution of the image data being higher in the sub-scanning direction than in the main scanning direction, the setting unit sets a higher intensity of the edge intensifying processing in response to the edge direction being along the sub-scanning direction than in response to the edge direction being along the main scanning direction.

Abstract: What is disclosed is a system and method for generating a destination profile LUT. In a manner more fully described herein, a high resolution LUT (e.g., 100-cube LUT) is received. Regions of high curvature of the gamut of an image output device are identified. A non-parametric dynamic optimization node selection method is utilized to select a subset of nodes from the high resolution profile LUT which captures these nonlinearities. Down-sampling the high resolution LUT produces a low resolution LUT. The low resolution LUT is up-sampled to a size of the high resolution LUT to obtain a reconstructed LUT. An error is then calculated between the reconstructed LUT and high resolution LUT. The process of node selection is iteratively repeated until all the subsets of nodes are considered. A destination profile LUT is then generated from the subset of nodes with the least error.

Abstract: Due to an accumulated error from the pair-wise registration, the stitched image may be blurred or have a gap when a loop is encountered. In order to remove the accumulated error, we identify a closed loop where a first image frame overlaps with a second image frame, the second image frame being captured earlier in a scanning sequence than the first image frame; register the first image frame with the second image frame; and apply a global optimization to adjust registration parameters for the plurality of pair-wise registrations of image frames within the closed loop using global constraints.

Abstract: Disclosed is an image inpainting apparatus and method using a restricted search region. The image inpainting apparatus sets a target image region to be inpainted in response to an image inpainting request, sets a surrounding image region, which has a preset size and includes the set target image region, sets a plurality of similar image regions by grouping similar pixels in the surrounding image region, divides the surrounding image region into the plurality of set similar image regions, divides the target image region according to the similar image regions, sets a search region of each divided target image region, and detects an image of an image region most similar to each divided target image region from the set search region of each divided target image region, thereby performing image inpainting.

Abstract: A method for controlling a tone reproduction curve of an image printing system includes generating an actual printed image tone reproduction curve using printed image data from a printed image sensor; determining a set of adjusted contone values by comparing the actual printed image tone reproduction curve with a target printed image tone reproduction curve, where the adjusted contone values being representative of the print contone values at which target color density data of the printed image is achieved in the image printing system; and determining adjusted image transfer surface reflectance data to update a target image transfer surface tone reproduction curve, where the adjusted image transfer surface reflectance data being obtained by interpolating the target image transfer surface tone reproduction curve at the adjusted contone values; and controlling subsequent toner image data to achieve the updated target image transfer surface tone reproduction curve.

Abstract: A method and a printing system are described capable of rendering more than 2 density levels at the device pixel level using precalculated rectangular screening tiles of finite size that define a spatially repetitive screening operation according to geometric clustered dot screen definitions for first, second and third separation screens that has the following characteristics: (A) the set of at least three separation screens is free of second order moiré; (B) the set of at least three separation screens consists of screens that have no internal moiré and/or screens that have a reduced sensitivity to amplification by process instability of any remaining level of intrinsic internal moiré; and (C) the screens have an optimized and balanced rosette structure leading to a reduction of visible patterning in overlays of the separation screens.

Abstract: A technique for cross-channel correction in real time for digital color printing in which the full resolution value of a selected colorant is combined with low resolution versions of the remaining colorants to provide a basis for correcting the selected colorant based upon the data for the other colorants employed. The pixel values of sub-samples of the remaining colorants are derived from the cell in which the full resolution selected colorant is taken; and, the desired output value is selected from a look-up table established for the known printing process.

Abstract: An image processing apparatus which reads an original to generate monochrome image data, comprises a determination unit configured to determine which of a first instruction to read the original using RGB sensors or a second instruction to read the original using a BW sensor is input; a reading unit configured to read the original using the RGB sensors when the determination unit determined that the first instruction is input, and read the original using the BW sensor when the determination unit determined that the second instruction is input; and a generation unit configured to generate monochrome image data by reading the original by the reading unit using the respective sensors.

Abstract: A method for performing auto-cleaning in a printer, which is designed for printing on a substrate, may include periodically printing an auto-cleaner print on the substrate in a predetermined frequency. The method may also include scanning the auto-cleaner print to obtain scanned image data of the auto-cleaner print. The method may further include analyzing the scanned image data to determine extent of presence of artifacts indicative of dirt or ink residue. The method may also include based on the extent of presence of the artifacts modifying the frequency.

Abstract: Systems and methods are provided for identifying candidates for trapping in a frame buffer by correlating display list object information stored in an object-ID plane with pixel data in the frame buffer. In some embodiments, the display list of objects may be generated from the PDL description of a document. In some embodiments, object boundaries may be computed by assigning unique identifiers to objects in the object-ID plane and using morphological techniques to identify object boundaries. Object boundary information may then be utilized to perform trapping on pixels in the frame buffer. The methods described may be performed on a computer and/or a printing device and implemented using one or more of combination of hardware, software, and/or firmware.

Abstract: An image-data acquiring unit acquires image data of an image. An image processing unit performs a predetermined image processing on the image data. A signal generating unit generates a scanning signal for determining a section of the image data for performing the image processing. A signal control unit stores waveform information of a scanning signal in a normal operation as a control signal, compares the control signal with the scanning signal generated by the signal generating unit, and detects an abnormality of the scanning signal. A scan control unit determines whether the image processing is to be continued based on a result of detection by the signal control unit.

Abstract: For each of a plurality of reference colors located at prescribed coordinates in a first color space (e.g., the RGB color space), there are associated, on an individual pixel row basis, correction vectors indicating correction amounts in the first color space. For each pixel datum of image data of first tone values (e.g., 256 tone values) of the first color space prior to a color conversion process, a correction process is carried out on the basis of the correction vector that has been associated with the pixel row to which a given pixel belongs, the correction vector also being associated with the reference color of a location surrounding the coordinates that indicate the pixel data in the first color space. The color conversion process and the halftoning process are carried out on image data composed of the pixel data that has been subjected to the correction process.

Abstract: Compensation for rendering device non-uniformities is provided for halftoned images. A spatially dependent tone reproduction curve (TRC) provides compensation values. Pixel location information is used to access TRC values. For example, the values are modification values. The modification values are added to the pixel values to generate combined values. Quantization is applied to the combined values to prepare compensated image data for rendering. For example, Rank Ordered Error Diffusion is applied to the combined values. The combined values may include diffused error from previously processed pixels. Gray values may be estimated for the respective pixels. The estimated gray values may be used to access compensation information from a TRC that is both spatially and gray value dependent. Mathematical basis decomposition is used to reduce TRC memory requirements.

Abstract: A system and method for three-dimensional (3D) acquisition and modeling of a scene using two-dimensional (2D) images are provided. The system and method provides for acquiring first and second images of a scene, applying a smoothing function to the first image to make feature points of objects, e.g., corners and edges of the objects, in the scene more visible, applying at least two feature detection functions to the first image to detect feature points of objects in the first image, combining outputs of the at least two feature detection functions to select object feature points to be tracked, applying a smoothing function to the second image, applying a tracking function on the second image to track the selected object feature points, and reconstructing a three-dimensional model of the scene from an output of the tracking function.

Abstract: An image generating apparatus and method for emphasizing an edge, based on image characteristics by extracting an edge region from an input original image, and an edge gain indicating a degree for emphasizing the edge region and an edge threshold indicating a degree of complexity between pixels are calculated for each of a plurality of image regions of the original image. The extracted edge region is combined with the calculated edge gain. Thresholding is performed by adjusting the calculated edge threshold for the edge region combined with the edge gain, and the thresholding-applied edge region is combined with the original image to output a final image. By adaptively adjusting an edge gain and an edge threshold for a portion where an edge needs to be emphasized and the other portions in an image having multiple image characteristics, both edge emphasis and noise cancellation can be achieved together.

Abstract: Methods and systems herein provide for color conversion. Such color conversion includes a method of optimizing gray component replacement in a color image that includes receiving a color image from an input imaging device (e.g., a digital camera, scanner, etc), determining a color gamut of an output imaging device, such as a printer, and generating a CIELab to CMY numerical model to convert the color image to a color space within the color gamut of the output imaging device. The method also includes generating a CMYK to CIELab numerical conversion model, removing a portion of CMY color values generated from the CIELab to CMY numerical conversion model, and replacing the removed portion of the CMY color values with black color values. The method also includes optimizing CMYK color values via a multidimensional optimization using the CMYK to CIELab numerical model.

Abstract: An image forming device includes a display unit, an original image display unit, a touch panel, a detecting unit, a selected region determining unit, an image forming unit, and a control unit. The display unit includes a display region. The original image display unit displays an original display image in the display region based on original image data. The touch panel is superposed on the display region. The touch panel enables a user of the image forming device to specify a prescribed position on the touch panel. The detecting unit detects a prescribed position touched by the user and generates position data based on the prescribed position. The selected region determining unit determines, based on the position data, a selected region in the original display image when the original image display unit displays the original display image in the display region. The image forming unit forms an image on a recording medium.

Abstract: A color look-up table includes a plurality of images recorded on a film. Each of the images being recorded on a separate picture of the film and containing at least a first level and a second level. The first and second levels having different pixel color values and are arranged to form a detectable geometric pattern on each of the pictures. The first field and a second field having detectable boundaries assigned to characterize distortions on the film.

Abstract: A method for modifying an input digital image having three color channels, to form a modified digital image suitable for use by an inkjet printer having reduced ink bleed artifacts comprising computing a transformed digital image containing at least a black color channel and a color dependent scale factor channel, computing a filtered black color channel using a convolution operation, and forming the modified digital image in response to the corresponding pixel values of the color dependent scale factor channel and the filtered black color channel, so that when the modified digital image is used to produce a printed image on an inkjet printer there are reduced ink bleed artifacts.

Abstract: In a watermarked document printing apparatus, secret information is divided, error correction encoding is performed to each divided pieces of information, and the secret information is converted into a pattern image and embedded in paper. In a watermarked document reading apparatus, after extracting signals from the pattern image on the paper, a reading error is detected by decoding the error correction code for each divided pieces of information, and the portion where the reading error exists is read again. The scanning process is performed again only to the portion where the decoding cannot be performed due to the temporal malfunction of the scanner or the like. Therefore, the pattern image can efficiently be obtained.

Abstract: The image forming apparatus includes first and second reading portions which read images of first and second faces of an original, an image forming portion which forms an image on a sheet based on image data read by the reading portions, a calculation portion which calculates difference between respective image data, a correction portion which calculates correction data to decrease difference of the image data based on the image data difference, and a control portion which controls the image forming portion so that an image for correction to correct the reading accuracy difference is formed on a sheet based on the correction data; and the calculation portion calculates difference between respective image data when the image for correction formed on a sheet is respectively read by the first and second reading portions, and the correction portion recalculates correction data based on the image data difference calculated by the calculation portion.

Abstract: Disclosed are methods and apparatus for reproducing an image using one or more halftone screens for one or more respective colorants in the methods and apparatus reducing the beating of one or more excitation frequencies with one or more harmonic frequencies associated with the halftone screens. According to an exemplary method, one or more halftone screens are selected such that the fundamental frequency of an excitation frequency coincides with a harmonic frequency of a halftone screen.

Abstract: A method and systems for calibrating a document scanner are provided. The scanner calibration method includes providing a geometrically operative black absorption device having a structural geometry that is capable of receiving light and limiting propagation of the received light, where the black calibration target has a total light reflectance of less than one percent. The method further includes powering on a light source of a document scanner to provide light toward the black absorption device, where the light source generates a noise signal when providing the light. The method further includes detecting, by a sensor of the document scanner, light reflected from the black absorption device and generating calibration signals based on the reflected light and the noise signal.

Abstract: The spread spectrum clock generator (SSCG) includes a phase comparator detecting phase difference between input clock and feedback clock; a charge pump supplying current depending on the phase difference; a loop filter converting the current to smoothed voltage; a voltage controlled oscillator generating a spread spectrum clock signal depending on the smoothed voltage; and a modulation signal generator generating modulation signal having amplitude depending on a modulation width set value. The SSCG further includes a modulation width detector detecting modulation width of the spread spectrum clock signal while comparing the modulation width with a modulation width target value to update the modulation width set value to narrow difference between the detected modulation width and the modulation width target value, followed by feeding back the updated modulation width set value to the modulation signal generator.

Abstract: When edge smoothing is applied to a portion where trapping was applied, the two processes are applied to a small region, thus causing image deterioration. Hence, the invention is configured to exclusively set trapping and edge smoothing execution conditions. Then, even when application of both trapping and edge smoothing processes to an entire image is selected, one of these processes is applied to each individual pixel or region. Alternatively, an execution completion flag may be set for one of these processes, and the other process may be executed with reference to that flag.

Abstract: Provided are a method and apparatus for removing show-through from a scanned image. The method includes scanning at least one line in a medium at a first intensity in a first scanning operation; scanning the at least one line in the scanning medium at a second intensity different from the first intensity, in a second scanning operation; and removing show-through from an image obtained during the first scanning operation based on a difference in a show-through effect between images obtained during the first and second scanning operations.

Abstract: A color look-up table includes a plurality of images recorded on a film. Each of the images being recorded on a separate picture of the film and containing at least a first level and a second level. The first and second levels having different pixel color values and are arranged to form a detectable geometric pattern on each of the pictures.

Abstract: A reference pixel PB is specified for a specified pixel P0 whose (luminance) value is below a threshold, for example, in the RGB data obtained in image pickup. The reference pixel PB should be on a straight line passing through the specified pixel P0 and the center O of the image and spaced from the specified pixel P0 by a distance, dr, depending on a reduction or expansion rate of a blue component (or B) image of the optical image corresponding to an optical zoom magnification in the image pickup. Only when the B value of the specified pixel P0 is greater than that of the reference pixel PB, the B value of the specified pixel P0 is replaced with that of the reference pixel PB. By expanding or reducing the blue component image alone for the original RGB data, image data is obtained in which the magnification chromatism is corrected.

Abstract: There is provided a method of and an apparatus for generating high sensitivity images in a low light level environment, the method including correcting an image acquired through short-time exposure in a low light level environment to an image corresponding to a reference exposure time defined for the low light level environment, the corrected image including a plurality of channels, detecting respective black levels for each of the channels, the detecting of the respective black levels being based on a black level intensity for the reference exposure time, adjusting the respective black levels for each of the channels of the corrected image to respective target black levels for each of the channels, and aligning a value of each of the channels using the respective target black levels.

Abstract: Methods, algorithms, software, apparatuses and systems for processing image data for imaging devices having irregular scan paths (e.g., scan paths that deviate from a conventional horizontal and/or straight line). The irregular scan paths generally correspond to actual locations of a line of output from an image output device (e.g., a printer). The method generally includes steps of selecting one or more of the input pixels, correlating a location of the selected pixel with a location on an irregular scan path, and producing an adjusted pixel based on a value of the selected pixel, the location on the irregular scan path, and/or values of one or more pixels near the selected pixel.

Abstract: A method for calibrating a position of a first register line in a register mark for a multi-color printing machine, said first register line consisting of a first color that does not offer sufficient contrast with respect to a printing material to allow detection above a determined threshold on a register sensor. A plurality of register marks, each consisting of at least one starting line, a background line and a first register line, is printed, said background line consisting of a second color which offers sufficient contrast with respect to the first color for detection above the specified threshold on the register sensor if the first register line is printed on the background line, and said background line having a width that is greater than the first register line, and said starting line, said background line and said first register line being printed with the use of the pre-determined control parameters, which normally cause the first register line to be printed on the background line.

Abstract: An image processing apparatus includes an anti-aliasing processing unit configured to perform an anti-aliasing process on gloss-control plane image data that specifies a type of a surface effect applied to a recording medium and a drawing area to which the surface effect is to be applied to the recording medium and on color plane image data indicative of a drawing area of a color image. The anti-aliasing processing unit corrects a pixel value of each pixel in the color plane image data to a value obtained by multiplying the pixel value by a first area ratio of a drawing area of the color plane image data before rasterization in each pixel, and corrects a pixel value of each pixel in the gloss-control plane image data to a value obtained by multiplying the pixel value by an area ratio of 100 percent.

Abstract: Streak compensation in a digital printer is provided utilizing a spatially varying Printer Model and Run Time updates to generate Spatially Varying Tone Reproduction Curves (STRCs) which are used as actuators to compensate for streaks during run time. A full width array sensor is used to measure streak profiles and the STRCs are used as actuators to compensate for streaks. Streak profile measurements taken at a limited number of area coverage levels combined with a Printer Streaks Basis Function Model are used to estimate and project the streak behavior at all area coverage levels and at all inboard-to-outboard spatial locations. The projection is then used in a pixel-wise error feedback control scheme to drive each profile to a desired shape, thereby compensating for streaks.

Abstract: An image processing apparatus includes: a calculating unit that sequentially selects pixels as a target pixel, on binary image data composed of plural color plates for each printing color after having been subjected to halftone-dot processing, and calculates a characteristic amount in each of plural preset areas around the selected target pixel on the basis of states of pixels in the areas; a determination unit that determines, on the basis of the characteristic amount in each of the areas calculated by the calculating unit, whether or not the target pixel is a pixel to be subjected to overlay processing; a decision unit that decides, for each of the color plates, a position of a pixel to be referred to when changing a pixel value of the target pixel, on the basis of a halftone-dot processing attribute for each of the color plates; and a changing unit that, if it is determined by the determination unit that the target pixel is the pixel to be subjected to the overlay processing, changes the pixel value of the

Abstract: An image recording apparatus including: a storing portion configured to store first image data based on which recording is performed on one of recording surfaces of a recording medium and second image data based on which the recording is performed on the other surface; a first density adjusting section configured to make an adjustment to a recording density for at least part of the first image data on the basis of an input of a user; a second density adjusting section configured to make an adjustment to a recording density for at least part of the second image data, the adjustment being reverse to the adjustment by the first density adjusting section; and a recording section configured to perform the recording on the basis of the first image data adjusted by the first density adjusting section and the second image data adjusted by the second density adjusting section.

Abstract: When a light source is in off state, a gray level of image data on a pixel-by-pixel basis is generated as a first black level and an average of gray levels of a portion of the image data corresponding to optical black image portions of sensor chips is generated as a second black level. After that, when an image of an original is read, an average of gray levels of the black image data on a line-by-line basis is generated as a third black level. The first black level is subtracted from a gray level of the image data on a line-by-line basis (an offset correction), and a difference between the third black level and the second black level is added to a gray level of the image data after being subjected to the subtraction on a line-by-line basis.

Abstract: A method for image processing in which an image of a bound document such as a book placed face-down on a document positioning plate is read and processed is provided. The method includes reading the bound document through the document positioning plate, displaying the read image, the read image having at least one of a shadow portion of a bound portion and a shadow portion of an edge portion, inputting information about a direction attribute of a rectangular area of the shadow portion in the displayed image, determining the direction attribute based on the input information, and correcting a density of the rectangular area based on the determined direction attribute.

Abstract: A directional anti-aliasing filter circuit includes an input node and an output node, a directional anti-aliasing filter having an input coupled to the input node, an adaptive gain control having an input coupled to an output of the directional anti-aliasing filter, a summer having a first input coupled to an output of the adaptive gain control, a second input coupled to the input node, and an output coupled to the output node, a texture detector for providing a texture adjust signal to the directional anti-aliasing filter and a texture adaptive gain signal to the adaptive gain control, an edge detector for providing an edge direction signal to the directional anti-aliasing filter, and a corner detector for providing a corner adaptive gain signal to the adaptive gain control.