Abstract: An apparatus includes an edge width detection circuit which detects an edge portion of image data and outputs an edge width of the detected edge portion, a ratio control amount generation circuit which generates a ration control amount in accordance with the edge width, a ratio generation circuit which generates a conversion ratio in accordance with the ratio control amount, and a pixel number conversion circuit which performs a conversion of pixel number of the image data using the conversion ratio, thereby enhancing sharpness of the edge portion in proper quantities.

Abstract: To solve the problem that when a space with a set width is inserted after each character to regularize the spaces between characters the overall character spacing is widened, making text less easy to read, there are provided a character control code storage unit (5) for storing, for each character display position, a character control code (CTD) including a character code (CC) and character width data (CW), and a positional control unit (4) for reading the character control code (CTD) for the present character display position from the character control code storage unit (5), and controlling the occurrence interval of the present character display position according to the character width data (CW) in the character control code (5) that was read and the previous character display position.

Abstract: A method of changing edge sharpness of an input image being formed from input pixels having intensity levels, the method including detecting pixel-to-pixel variations in the intensity levels in at least one direction in the input image, thereby generating local pixel variation patterns; determining a localized zoom ratio based on the local pixel variation patterns; controlling edge sharpness by changing the localized zoom ratio setting interpolation points with spacing between the interpolation points varying based on the localized zoom ratio and a basic zoom ratio; and generating output pixels from the input pixel by interpolation at the interpolating points.

Abstract: The present invention relates to an image processing device including pixel interpolation, such as a pixel interpolation device, a line interpolation device, an image size conversion device and an image interpolation device. The pixel interpolation device according to the present invention includes an interpolation pattern table, which outputs an interpolation direction data designating interpolation directions including directions joining intermediate points of pixels. The interpolation pixel data is calculated based on the pixel data located in the interpolation direction designated by the interpolation direction data. The image interpolation device, the pixel number conversion device and the line interpolation device according to the present invention includes the pixel interpolation device described above.

Abstract: A first edge width correction process (2) is carried out in which edge widths are corrected by an interpolation process using zoom ratio control values (RZC) generated according to the edge widths in image data; an enlargement processing process (3) that enlarges the image data with edge widths corrected by the first edge width correction process (2) is carried out; a second edge width correction process (4) similar to the first edge width correction process is carried out on the enlarged image data; and an edge enhancement process that enhances edges in the image data with edge widths corrected by the second edge width correction process is carried out. An image processing apparatus is obtained that mitigates the loss of sharpness in an enlarged image and accordingly makes it possible to provide better picture quality.

Abstract: An object of the present invention is to provide an image processing apparatus and image processing method capable of obtaining better picture quality by appropriately improving the sharpness of edges of an image. In order to achieve the object, the image processing apparatus comprises a zoom ratio control means for detecting edges in image data and generating zoom ratio control values according to the widths of the detected edges; an edge width correction means for correcting the edge widths by carrying out an interpolation process on the image data according to the zoom ratio control values; an enhancement value calculation means for detecting high frequency components of the image data with the corrected edge widths, and calculating enhancement values for enhancing the edges of the image data according to the detected high frequency components; and an edge enhancement means for enhancing the edges of the image data by adding the enhancement values to the image data with the corrected edge widths.

Abstract: An image is processed by detecting pixel-to-pixel variations in brightness level, generating high spatial frequency information related to the variations, setting interpolation points with a spacing that varies according to the high spatial frequency information, and generating new pixels by interpolation at the interpolation points. By increasing the zoom ratio in one part and reducing the zoom in another part of each edge in a continuous manner, this method can mitigate edge degradation when an image is enlarged or reduced, without introducing discontinuities or other image artifacts. It also provides a convenient way to adjust edge sharpness in an image.

Abstract: Interpolation data for a missing pixel are obtained (4) after a correction (3) for variations in the characteristics of the imaging devices (8(1), 8(2)). The correction for variations in characteristics includes, for example, a black level correction (9) and a sensitivity correction (10). The interpolation includes, for example, interpolation calculations (14(1), 14(2)) such that a mean value of a plurality of pixels including the missing pixel and a mean value of a plurality of pixels not including the missing pixel become equal and an interpolation calculation (14(0)) that takes the mean of the pixels to the right and left of the missing pixel, the calculation with the least error being selected (13, 15). Thus missing pixels in highly periodic images can be properly interpolated, and interpolation can be performed with high precision even when there are variations in the sensitivity characteristics of the individual imaging devices constituting the contact image sensor.

Abstract: An image display device detects mutually adjacent bright and dark parts of an image and detects fine bright lines in the image. Bright parts of the image that are not fine bright lines are smoothed if they are adjacent to dark parts. This smoothing scheme improves the visibility of dark features on bright backgrounds without impairing the visibility of fine bright lines on dark backgrounds.

Abstract: An image processing method extends n-bit input image data by ? bits to generate (n+?)-bit source data, where n and ? are positive integers, and smoothes the source data. The maximum difference between gray levels of the unsmoothed source data in an area localized around each pixel is calculated, and a mixing ratio is determined from the maximum difference. The smoothed and unsmoothed source data are mixed according to the mixing ratio to generate output image data. In areas with gradually changing gray levels, the output image data are weighted toward the smoothed source data, mitigating image degradation due to quantization and gamma correction. In areas with sharp edges, the output image data are weighted toward the unsmoothed source data, preventing a loss of edge sharpness.

Abstract: A color demodualation device having an AD converter, a phase signal generator, a burst data generator and a multiplier. The AD converter produces digital samples of chrominance signal at a frequency four times a color subcarrier frequency, and the phase signal generator generating a phase signal for identifying phases of a burst signal and color subcarrier signals modulated by respective B-Y and R-Y signals. The burst data generator produce burst data corresponding to the burst signals modulated by respective B-Y and R-Y signals. The burst respective color subcarrier signals according to the phase signal. The multiplier produces products of the burst data and the digital samples of the chrominance signal, from which digital samples of the respective R-Y and B-Y signals are produced.

Abstract: Missing-pixel interpolation data are obtained such that the mean value of a plurality of pixels constituting a group of pixels including a missing pixel is equal to the mean value of a plurality of pixels constituting a group of pixels not including the missing pixel. For example, missing-pixel interpolation data are obtained by (1) obtaining a sum (SL) of the values of pixels other than the missing pixel (L) in the k pixels constituting the group (LC) of pixels including the missing pixel, (2) obtaining a sum (SA) of the values of k pixels constituting a group (NA) of pixels not including the missing pixel, and (3) taking the difference between these sums. This makes it possible to reduce interpolation error when a highly periodic image with missing pixels is interpolated.

Abstract: An image display device includes a smoothing unit that filters the image data to be displayed. According to one aspect of the invention, only bright parts of the image that are adjacent to dark parts are smoothed, thereby improving the sharpness of dark dots and lines displayed on a bright background. According to another aspect, different primary colors are smoothed with different characteristics, enabling unwanted colored tinges to be removed from the edges of white areas. According to still another aspect, smoothing moves the luminance centroids of all primary colors in a direction in which the display screen is scanned, to reduce ringing effects without needless loss of edge sharpness.

Abstract: In a period from temporal storage of a video signal to reading and displaying of the video signal, an average value 121 of the brightness levels obtained from a video signal before the video signal is stored in a storage means 3 and a predetermined target value 122 are used to perform a calculation by using a proportionality term and an integration term so that a quantity of limited electric currents is obtained. Moreover, the quantity of limited electric currents is provided with a non-response region or a hysteresis characteristic.

Abstract: A tone step detector detects whether the tone of n-bit input image data varies gradually, and generates a tone processing control signal indicating that a tone step is contained. A bit shifter bit-shifts the n-bit input image data to the left by ? bits, to generate (n+?)-bit image data. A tone processor smoothes the image data of the (n+?)-bit image data generated by the bit shifter, in the region where the tone processing control signal indicates that a tone step is contained, to generate (n+?)-bit image data having been smoothed in the above-mentioned region. Because of the selective smoothing, degradation in the image quality due to quantization is reduced even when an analog image signal whose tone varies gradually is input.

Abstract: A pixel interpolation circuit according to this invention includes a plurality of interpolation circuits each calculating interpolation candidate data of a interpolation pixel and test interpolation data of a plurality of pixels neighboring the interpolation pixel using different interpolation methods, a determining circuit for selecting one of the interpolation circuits based on a difference between the test interpolation data and actual pixel data, and an output circuit for outputting the interpolation candidate data calculated by the selected interpolation circuit as the interpolation pixel data.

Abstract: An apparatus includes an edge width detection circuit (1) which detects an edge portion of image data (DI) and outputs an edge width (W) of the detected edge portion, a ratio control amount generation circuit (2) which generates a ratio control amount (ZC) in accordance with the edge width (W), a ratio generation circuit (3) which generates a conversion ratio (Z) in accordance with the ratio control amount (ZC), and a pixel number conversion circuit (4) which performs a conversion of pixel number of the image data (DI) using the conversion ratio (Z), thereby enhancing sharpness of the edge portion in proper quantities.

Abstract: An apparatus and method are disclosed for displaying an image having high frequency components. The image is displayed on a display device that includes a plurality of display elements arranged in both horizontal and vertical directions. The display elements represent colors, such as red, green and blue. A pixel data generator generates for each display element first pixel data corresponding to the luminance levels of red, green and blue colors in the image. A smoothing filter eliminates false colors in the image by applying weighting coefficients to the first pixel data to modify the luminance levels of the first pixel data, thereby producing second pixel data having second color element data corresponding to luminance levels of the respective colors. Each display element of the display is driven in accordance with the second color element data.

Abstract: In order to reduce the total capacity of a ROM used for adjustment of the black level and the white level of a digitized luminance signal for a television receiver, for example, a comparator compares the input luminance signal with a predetermined threshold value, a NOT gate inverts the input luminance signal, a first switching unit selects the input luminance signal or the output of the NOT gate, a ROM outputs an adjustment characteristic signal responsive to the output of the first switching unit, a multiplier multiplies the output of the ROM by a weighting signal and outputs the result of the multiplication as an adjustment value, a subtractor subtracts the adjustment value from the input luminance signal, an adder adds the adjustment value to the input luminance signal, and a second switching unit selects the output of the subtractor or the output of the adder.

Abstract: An image display device includes a smoothing unit that filters the image data to be displayed. According to one aspect of the invention, only bright parts of the image that are adjacent to dark parts are smoothed, thereby improving the sharpness of dark dots and lines displayed on a bright background. According to another aspect, different primary colors are smoothed with different characteristics, enabling unwanted colored tinges to be removed from the edges of white areas. According to still another aspect, smoothing moves the luminance centroids of all primary colors in a direction in which the display screen is scanned, to reduce ringing effects without needless loss of edge sharpness.