Abstract: An average filter or filters is used in line with the output of an interpolation filter to downscale an image. The interpolation filter upscales a source image or bitmap of pixels into an intermediate form and the average filter or filters downscales the intermediate form to a destination image or bitmap of pixels. This configuration incorporates a small amount of logic with a relatively low incremental cost, enabling high quality downscaling of text and computer graphics content. The invention achieves quality comparable to a filter/scalar combination with more taps or a separate decimation pass.

Abstract: An apparatus which processes a digital image and a method therefor which can reduce an error when calculating an output value obtained by interpolating pixel values of the input digital image. The apparatus includes an interpolation processing unit which interpolates an input digital image, and a controller which measures an interpolation interval of pixel values of the digital image, calculates a coefficient by substituting the interpolation interval for a coefficient equation stored in a register, and calculates an interpolation node for the digital image by substituting the coefficient and an output pixel position value of the digital image for an interpolation node calculation equation. The controller controls the interpolation processing unit so as to interpolate the digital image to the interpolation node. As a result, it is possible to reduce an error between an interpolated output pixel position value and an output pixel position value for the pixel values of the input digital image.

Abstract: A color chart includes color patches associated with all vertexes of a rectangular parallelepiped defined by a base coloring amount (QCb, QMb, QYb) comprising combinations of minimum coloring amounts QCb, QMb and QYb of monochromes of cyan, magenta and yellow in a coloring amount space represented by three axes of coloring amounts of cyan, magenta and yellow, a maximum coloring amount QCmax of monochrome of cyan, a maximum coloring amount QMmax of monochrome of magenta M, and a maximum coloring amount QYmax of monochrome of yellow Y in the coloring amount space, and in addition a color patch associated with an intermediate point located between two vertexes on a straight line coupling the two vertexes with one another, even if any two vertexes of the rectangular parallelepiped are selected.

Abstract: A method of, and apparatus for, dithering an image to be printed. Color component values of odd and even pixels of an image are stored in a dither cell. The dither cell is mapped to a staggered dither cell such that lines of odd pixel component values are staggered relative to lines of even pixel component values. Addressing of the staggered dither cell is determined by an address generator that also addresses a buffer storing an up-interpolated image. Corresponding values in the staggered dither cell and the buffer are compared to determine which nozzles of a printhead are fired.

Abstract: An image processing apparatus, which performs color conversion for input tone data in an RGB color space to obtain tone data for a CMY color space, and which performs halftone processing to convert the tone data in the CMY color space to image reproduction data, is characterized in that a gamma characteristic A for an output density for a tone in the RGB color space is identical to a gamma characteristic B for an output density for a tone in the CMY color space in the halftone processing. In accordance with the invention, for the color conversion, even when the tone data for the RGB color space between the grid points of a color conversion table is obtained by interpolating the tone data for the CMY color space, the halftone process is performed for the RGB tone data in accordance with the same gamma characteristic B. Thus, image reproduction data can be obtained that provide the same output density as the output density allocated for the tone data of the RGB color space.

Abstract: An image input unit acquires a first image and a second image. A matching processor computes a pixel matching between the images so that corresponding points are obtained on the second image with respect to lattice points of a mesh defined on the first image. A result thereof is recorded as a corresponding point file. An intermediate image generator generates an intermediate image of the first image and the second image based on the corresponding point file. Since the corresponding point file is composed of corresponding lattice points alone rather than corresponding pixels or the like, the amount of data is relatively small, and thereby allows efficient implementation of and application to various image effects, motion picture compression, on-line commodity presentation, and mobile applications.

Abstract: An image processing system and demosaicing method are provided to calculate estimated missing color sensor values in an image using a linear prediction from the raw color sensor value at the current pixel location. The raw image is divided into regions of sensor values, and the linear relations between color planes for each region are determined by a regression method that calculates the degree to which different color planes co-vary within each region The missing color sensor values per region are calculated as a scaled and shifted version of the raw color sensor values using linear regression coefficients determined from the local linear regression process.

Abstract: A color converting device converts input CMYK data into output color data in a predetermined different format. The color converting device comprises a contrast emphasizing unit emphasizing a contrast of the output color data corresponding to the CMYK data representing a black-character color more than a contrast of the output color data corresponding to the CMYK data representing a non-black-character color.

Abstract: A three-dimensional space formed by three-channel input signals is divided into a plurality of polyhedrons having vertices at points corresponding to a conversion table. A particular polyhedron is determined which is associated with the points corresponding to the three-channel input signals. The nonlinear interpolation is carried out using the conversion data corresponding to the vertices of the intended polyhedron thus determined and the conversion data corresponding to the vertices of the polyhedrons in surface contact with the intended polyhedron.

Abstract: A method of mapping a color produced by an image device in a presentation color space to a destination color space including steps of receiving the color from the image device, determining if color is to be preserved, converting the color to the destination color space using a default profile if it is determined that color is to be preserved, and converting the color to the destination color space using a device-specific profile absent a determination that color is to be preserved.

Abstract: To approximate with precision the nonlinear output characteristic of an output device and enable high-precise color reproduction, a method is provided to convert a device-independent color space into an output device-dependent color space. A colorimetry value of a color patch output by the output device and represented in the device-independent color space is input, and a colorimetry value close to a conversion target value represented in the device-independent color space is extracted from the input colorimetry value. According to a distance between the input and extracted colorimetry values in the device-independent color space, there is performed a weighting process for a color value corresponding to the extracted colorimetry value and represented in the output device-dependent color space, to obtain a color value corresponding to the input colorimetry value and represented in the output device-dependent color space.

Abstract: Briefly, in accordance with one embodiment of the invention, a method of using hue to interpolate color pixel signals includes the following. For a particular pixel location in a subsampled color image, differences in hue are compared for two mutually orthogonal directions across the particular pixel location. A color signal value for that particular pixel location for a color plane other than the color plane of the pixel signal value in the subsampled color image of that location is computed. The computation includes relatively weighing the differences in hue values, the relative weights depending, at least in part, on the difference in hue value in one direction relative to the other.

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

Abstract: An image interpolation method and apparatus by which to quickly generate and display motion pictures using a small amount of data. An image input unit inputs a first image and a second image. A matching processor computes a pixel matching between those images so that a corresponding point is obtained on the second image with respect to a lattice point of a mesh on the first image. The matching processor stores the matching results recorded as a corresponding point file. An intermediate image generator generates an intermediate image between the first image and the second image based on the corresponding point file. In particular, in generating the intermediate image, an attribute of the pixels on one image may be used as such without the attribute being interpolated between pixels of each image. Thus, when generating intermediate images, only one image and a smaller corresponding point file can be used.

Abstract: Methods and apparatus, including computer program products, implementing and using techniques for using a color table defining a mapping from a source color space representing colors in source color coordinates to a destination color space representing colors in destination color coordinates. An input color in the source color space is received. A location of the input color in a cell of the color table is determined in terms of cell coordinate values in a cell coordinate system. The cell coordinate values are ordered to determine a processing order of the dimensions of the source color space. The cell coordinate values are used to calculate an output color in the destination color space, making no more interpolation calculations than the number of source color space dimensions multiplied by the number of destination color space dimensions.

Abstract: There is disclosed an image processing apparatus for generating an address based on a difference (MAX?MIN) between a maximum value MAX and a minimum value MIN among signals CMY indicating three primary colors of a color image for each pixel, and generating a black ink signal based on data read from a lookup table in which the data is read from the generated address, so that a black ink strength is independently set with respect to density and chroma of the image. Moreover, the lookup table with the black ink signal and an undercolor signal stored therein has a storage capacity of a number obtained by totaling a number at which the difference (MAX?MIN) between the maximum value MAX and the minimum value MIN is an integral multiple of a predetermined value and a number at which the difference is other than the integral multiple and the maximum value MAX is equal to a maximum value of a defined region.

Abstract: A method of determining colorant amounts to be laid down in a color printer includes determining an initial set of cyan, magenta and yellow (CMY) values; ordering the initial set of CMY values to determine the largest, middle and smallest values of the three values and generating an ordering vector; selecting a gamut center black generation LUT and two gamut boundary black generation LUTs from a set of black generation LUTs from a selection table; indexing the selected black generation LUTs to determine black values for each black generation LUT as a function of the minimum of the CMY values; interpolating a final output black colorant amount from the black values, and interpolating final output CMY colorant amounts from the initial set of CMY values, the maximum CMY ink limit constraint, and a set of boundary threshold values.

Abstract: An image processing apparatus includes a command analyzing unit obtaining color information of each endpoint of an object by analyzing a drawing command, a draw processing unit obtaining the color information of successive scanned points inside the object through incremental interpolation of the color information, thereby successively producing the color information for an entirety of the object, and an image processing unit processing the color information outputted by the draw processing unit.

Abstract: Disclosed are a method and apparatus for forming a color transform lookup table which helps output a smooth image having no pseudo contour and excellent in granularity. On the basis of a previously formed table, a color space is expressed by a basic triangle of white-primary color-black, and output signal values corresponding to lattice points in this basic triangle are calculated by linear interpolation. Black ink and cyan ink are replaced by setting a straight line AB, as a boundary line, connecting two points immediately before black ink begins to be introduced on two sides of the basic triangle.

Abstract: A color conversion method and apparatus for a compact printer system. An image processor converts a stored image from a first tri-color space to a second tri-color space. Resultant transformation values are read from lookup tables for each color component of the stored image pixels and a single cycle interpolator unit performs linear interpolation to generate a single color component in the second tri-color space in 14 cycles. In one example, the RGB form is converted to the L*a*b* form and additional L* components are used in sharpening a converted image.

Abstract: Upon scaling input image data and outputting the scaled image data, an address arithmetic processor determines phase information, which indicates the distances between the position of the pixel of interest after scaling and neighboring pixels of an original image, in accordance with the scale of that scaling, a coefficient arithmetic processor calculates filter coefficients in a filter process in accordance with the determined phase information, and a filter processor executes the filter process of the input image data by convolution operations on the basis of the calculated filter coefficients and outputs multi-valued image data. An LUT converts the density of the multi-valued image data in correspondence with the density characteristics of a printer, and a binarization processor binarizes the multi-valued image data and outputs binary image data to an image storage unit.

Abstract: Disclosed is an image interpolation method and apparatus thereof. The present invention includes the steps of searching an edge direction to be used for interpolation by a pixel matching using input pixels and generating a pixel to be substantially interpolated by referring to pixels located on the searched edge direction. The present invention includes the steps of carrying out a first interpolation on input pixels using linear interpolation and finding weighted value coefficients in accordance with a relationship between the first interpolated pixel and the adjacent input pixels to be used for interpolation and preparing a pixel to be substantially interpolated by adaptive weighted interpolation applying the found weighted value coefficient to the adjacent input pixels. Accordingly, the present invention minimizes the blurring and is free of geometrical distortion.

Abstract: A method of, and an apparatus for, image conversion. The three color channels of a Bayer mosaic image are up-interpolated from input space to output space. The pixels sampled from each two-dimensional color plane of the Bayer image are convolved with a coefficient kernel for each color. To facilitate reconstruction and resampling, the color space for a dominant pixel color of the Bayer image is effectively rotated. The generation of each color value for a given pixel coordinate is carried out in parallel using an identical convolve unit and a dedicated coefficient kernel for each color.

Abstract: A color image pickup device is provided with image pickup elements having color separation filters, respectively, wherein one array pattern of the color separation filters corresponds to four pixels that are vertically and horizontally adjacent to each other; a storage circuit for storing filter-transmitted signals corresponding to the respective pixels and supplied from the image pickup elements; a signal processing circuit for obtaining a luminance value and a color-difference signal for each pixel, using the filter-transmitted signals corresponding to the respective pixels and stored in the storage circuit; and a resolution conversion circuit for performing interpolation using the luminance values and the color-difference signals outputted from the signal processing circuit, and the filter-transmitted signals corresponding to the respective pixels and outputted from the image pickup elements, thereby generating a luminance value and a color-difference signal corresponding to a pixel to be newly generated.

Abstract: In an image processor, an image processing method, and an image processing program recording medium, an intensity of a new pixel is calculated on the basis of an intensity of a pixel of interest, an intensity of an original pixel adjacent at an upper side of the pixel of interest, an intensity of an original pixel adjacent at a lower side of the pixel of interest, an intensity of an original pixel adjacent at a left side of the pixel of interest, and an intensity of an original pixel adjacent at the right side of the pixel of interest.

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

Abstract: A controller for a printer module having a printhead that prints an image on printable media including a low speed central processing unit with associated program memory storing program steps for execution by the central processing unit to operate the printer module and associated scratch memory to store program variables. An image to be printed is stored in an image storage memory of approximately 1.3 Mbytes. An image access unit accesses the image and transfers the image to a printhead interface on command from the central processing unit. The printhead interface transforms the image to a 1600 dpi dithered CMY image for printing by a monolithic printhead. The controller also includes one or more interface units communicating with components of said printer module under control of the central processing unit. A Serial Bus interface communicates with the Serial Bus of a compact printer system to transfer data and power between modules.

Abstract: A system and method are proposed for the printing of all possible colors, including all permutations of primary inks used to make processed colors, in equal increments and of a size easily measurable with a device that will convert the colors into standard color coordinates. These colors are categorized and used to determine the ability of the output device to reproduce a source color. Each color printed within the gamut of an output device is identified and correlated to independent color coordinates. The primary color recipe necessary to reproduce a reference color within the gamut of the output device is identified. The magnitude of deviation of out of gamut source colors is determined, and the closest in gamut colors are specified through methods of interpolation and nearest neighbor. Furthermore, the alteration in gamut size can be predicted based upon image manipulation processes associated with the workflow.

Abstract: In an image processing method, a square submatrix formed from adjacent original pixels is equally divided into small square regions along the X- and Y-coordinate axes. Approximate points are set at the vertexes of the regions. Interpolation coefficients are derived based on a predetermined interpolation function. Interpolation coefficients normalized so as to adjust the sum of the coefficient values of interpolation coefficients used for one interpolation operation to 2k (k is a positive integer) are calculated, and stored in a coefficient buffer in advance. A new pixel position of each pixel constituting a new image is calculated in accordance with magnifications representing enlargement/reduction ratios along the X- and Y-coordinate axes for an original image. An approximate point closest to the new pixel position is selected as the approximate point of the new pixel position. Interpolation coefficients corresponding to the interpolation original pixels are read out from the coefficient buffer.

Abstract: A method and a system for processing images using interpolating. A variation value for different sets of pixels is determined, and the set of pixels with the highest correlation (lowest numeric value) is selected. A missing color at a given pixel is expressed in terms of the information contained in the selected set of pixels. If the variation value is below a certain threshold, due to noise or other factors, an alternative set of pixels using a different variation method may be selected. The missing color is estimated as a weighted sum of, e.g., the green samples divided by the weighted sum of, e.g., the red samples multiplied by the sampled value from the pixel to be estimated.

Abstract: An image signal processing method and an image signal processing apparatus for processing the color component signal obtained from a solid-state image pickup device including an arrangement of a plurality of photoelectric elements and a color filter arranged in the light receiving section of each pixel corresponding to the photoelectric element, an image signal generating apparatus and a computer program product for the image signal processing method. A color component signal is fetched from a designated pixel corresponding to the photoelectric element having a filter that can transmit the green light on a line of the solid-state image pickup device. A color component signal is also fetched from a pixel corresponding to the photoelectric element having a filter for transmitting at least the green light on another line, which pixel is located in the neighborhood of the designated pixel.

Abstract: Reproduction apparatus calibration is effected by rendering not only neutral density target patches but also a sampling of intentional off-neutral patches produced by selecting sets of red, green, and blue (and sometimes black) input code values for those patches which deviate from sets of values that would produce neutral densities. Then, by analyzing how the measured densities of all the patches change with changes in code values, the optimum set or sets of the three (or four) input code values, that when used together produce a desired set of aim neutral density patches in a single iteration, are determined.

Abstract: In the conversion of a video signal from interlaced to progressive scanning, the value of each pixel on an interpolated scan line is calculated by a procedure that includes calculating similarity values for pairs of pixel blocks located in point-symmetrical positions on opposite sides of the interpolated pixel; deciding whether similar edges are present in corresponding positions in the two pixel blocks constituting each pixel block pair; selecting an interpolation direction corresponding to the most similar pixel block pair among the pixel block pairs in which the similar edges are present; and using the pixels disposed at or closest to the centers of the two pixel blocks in this pixel block pair as reference pixels. Restricting diagonal interpolation directions to pixel block pairs in which similar edges are present improves the accuracy of the interpolation direction.

Abstract: Color imaging devices, color imaging methods, and color separation methods are described. According to one embodiment, a color imaging device includes interface circuitry configured to access color image data of an initial color space for a plurality of pixels, color space conversion circuitry coupled with the interface circuitry and configured to convert the color image data for some of the pixels from the initial color space to a first output color space representation and to convert the color image data for others of the pixels from the initial color space to a second output color space representation different than the first output color space representation, and an image engine coupled with the color space conversion circuitry and configured to form a color image using the color image data of the first and the second output color space representations.

Abstract: A CCD is driven by a drive circuit, whereby an independent readout drive of all pixels is carried out. Data of 4 lines are input in parallel to a two-dimensional register array by 4 scanning line delay devices. Interpolation is carried out for every color signal of green, magenta, cyan and yellow by an interpolation processing circuit according to data corresponding to pixels of 4 rows and 6 columns. A color difference signal generation circuit carries out a color separation process on the basis of the color signal subjected to an interpolation process.

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: When executing a color conversion process, a CPU determines whether a CMYK conversion indication flag Fc has been set. If the flag Fc has been set, then the CPU reads data of an RGB-CMYK conversion table and performs a cube interpolation process by using the RGB-CMYK conversion table. On the other hand, if the flag Fc has not been set, then the CPU reads data of an RGB-RGB conversion table and performs a triangular pyramid interpolation process by using the RGB-RGB conversion table.

Abstract: A digital camera is provided having a lens for focusing light from an image through a RGB mosaiced filter on to a solid state photosensor array containing a matrix of CCDs. The CCDs provide a single-channel mosaiced image output. A demosaicing process includes a first color transformation after separation for determining luminance and a luminance interpolation for interpolation of missing luminance components. The demosaicing process further includes a second color transformation for obtaining chrominance components. A chrominance interpolation for interpolation of missing chrominance components and an inverse color transformation transforms the components into the RGB space for combination into an image output.

Abstract: Upon chromakey processing, 4×4 transformation matrix is provided through which a backing color selected is transformed to the original point and monochrome color is transformed to vertically distribute at a spot away from the original point along an axis. Matrix multiplication comprising only addition and multiplication is applied to a foreground image data signal to generate a masked output image and a color-processed foreground output image without requiring complex arithmetic operations.

Abstract: An image processing device for processing input image data includes a correction unit that corrects for image deterioration caused by changes in image magnification; a reduction/enlargement unit that, based on the magnification, thins out the pixel data when reduction is being performed or carries out inflation of the pixel data when enlargement is being performed; and a controller that changes the operation of the correction unit in response to the magnification.

Abstract: In case print operation is performed using only a single ink, a problem arises. If a profile is referred to, it is impossible to use only the single ink. If a profile is not referred to, the color tone differs from that rendered when with respect to the single color, color conversion is carried out referring to a profile. Input image data wherein colors are rendered by the combinations of a plurality of color component values is acquired. Then, the input image data is transformed into output image data wherein colors are rendered by the combinations of gradation values corresponding to ink colors used in a printing device when print operation is performed. At this time, a color conversion table for transforming a specific color in input image data into output image data wherein colors rendered only by a specific color component value are specified is generated, referring to a previously stored profile.

Abstract: One single-stage proofer RIP replaces a conventional setup of two proofer RIP stages in series. Preliminary profile and data processing usually performed at the first of the conventional RIP stages, and source input terminal of the second, are instead performed in a preprocessor at the image-originating or production-hardcopy-printer station. The preprocessor combines production-printer forward and inverse profiles with a profile for the monitor, associated computer or graphics program—to form a single profile that converts monitor signals to perceptual data representing appearance of the predicted production copy. This three-way composite profile is applied to the source terminal of the single-stage proofer RIP.

Abstract: An original image signal, which represents an original image and are composed of original image signal components representing a plurality of sampling points, that are arrayed at predetermined intervals and in a lattice-like form, is obtained. A judgment is made as to whether an interpolation point belongs to an image edge portion, at which the change in the original image signal is sharp, or belongs to a flat portion, at which the change in the original image signal is unsharp. Interpolating operation processes, one of which is to be employed for the interpolation point, is changed over to each other in accordance with the results of the judgment.

Abstract: A system and method for printer control and color balance calibration. The system and method address the image quality problems of print engine instability, low quality of color balance and contouring from the calibration. The method includes defining combinations of colorants, such as inks or toners that will be used to print images, defining a desired response for the combinations that are to be used and, in real time, iteratively printing CMY halftone color patches, measuring the printed patches via an in situ sensor and iteratively performing color-balance calibration based on the measurements, accumulating corrections until the measurements are within a predetermined proximity of the desired response. The calibration is performed on the halftones while they are in a high quantization resolution form.

Abstract: Systems and methods are disclosed of a smooth gray component replacement strategy which utilizes the full gamut of a printer device. A CMY to CMYK gray component replacement transform is disclosed which inherently exploits the full gamut of the printer, by transforming points in CMY cube to L*a*b* color space, scaling the obtained values so they fill the maximum gamut obtainable with the printer device and calculating the CMYK values needed to obtain the scaled L*a*b* values. The CMY to CMYK transform is then smoothed with an averaging filter that does not change CMYK values at the corners. The entire color gamut is adequately sampled and small changes in CMY do not produce large jumps in L*a*b*.

Abstract: A color data converter includes a plurality of memories configured to store lattice points for a color space. The lattice points of the first axis are assigned to memories in a sequential manner. The lattice points along the other two axes are assigned to memories in an alternating manner.

Abstract: Tetrahedral interpolation by rewriting the interpolation in terms of ordered differentials and color differences to lower the computational complexity. Additionally, hardward architecture allows efficient implementation.

Abstract: An image interpolating device comprises a color filter, in which R, G, and B color filter elements are disposed in a checkerboard arrangement, and an imaging device which generates R, G, and B-signals corresponding to the color filter elements. In an interpolation process, the difference between a first comparative value V1 and a second comparative value V2 is compared. V1 is determined using color signals of pixels offset in the right and left directions to an objective pixel. V2 is determined using color signals of pixel offset in the upper and lower directions to the objective pixel. When V1 is less than V2, an arithmetic mean of G-signals of pixels offset in the right and left directions by one pixel is obtained as an interpolated G-signal. When V1 is not less than V2, an arithmetic mean of G-signals of pixels offset in the upper and lower directions by one pixel is obtained as the interpolated G-signal.

Abstract: The present invention is related to a color difference judgment apparatus for judging a color difference between a first color and a second color in RGB color space. The method is comprising: distance calculating means for calculating distance between the first and second colors in RGB color space; threshold-value candidate storage means for storing a plurality of threshold-value candidates; threshold-value selecting means for selecting a threshold value from among the plurality of threshold-value candidates that have been stored in the threshold-value candidate storage means; and comparing decision means for comparing the distance calculated by the distance calculating means and the threshold value selected by the threshold-value selecting means and deciding that the color difference between the first and second colors lies within an allowable range if the distance is less than the threshold value.

Abstract: An improved interpolation method in which a threshold value used for determining a pixel value of a pixel generated by interpolation according to a context which is a state value of adjacent pixels. In the interpolation method, the ambiguity between the interpolation value and the threshold value is removed by using the context, thereby reducing the blocking and smoothing phenomena in the restored binary image.