Abstract: An image processing apparatus for applying a color balance correction to input image data, comprises a first highlight color calculation unit which estimates a light source at the time of shooting from pixel values of the image data, converts color values of the image data based on a condition of the estimated light source at the time of shooting, and calculates a first highlight color; a second highlight color calculation unit which calculates a second highlight color from the image data; a third highlight color calculation unit which calculates a third highlight color based on a positional relationship between the first highlight color and the second highlight color on a color space; and a correction unit which attains the color balance correction by converting the pixel values of the image data using the third highlight color.

Abstract: A laser diode drive circuit includes a laser diode (LD), a modulation-current differential drive circuit, a bias-current differential drive circuit, a first inductance connected between an anode of the LD and a positive power source, a second inductance connected between a cathode of the LD and a negative-phase output terminal of the bias-current differential drive circuit, a first resistor connected to a connection point of the anode of the LD and the first inductance and connected to a negative-phase output terminal of the modulation-current differential drive circuit, and a second resistor connected to a connection point of the cathode of the LD and the second inductance and connected to a positive-phase output terminal of the modulation-current differential drive circuit, and a positive-phase output terminal of the bias-current differential drive circuit is connected to the connection point.

Abstract: In low-resolution processing (reduction processing) in which input image data is separated into character print data and image print data to generate print data of lower resolution than that of the input image data, if a plurality of pixels is simply reduction-processed to one pixel, color of a color image surrounding a character may change. In an image processing method, calculation for performing reduction processing so that the plurality of pixels in the input image data corresponds to one pixel in the print data is performed as follows. A ratio of using a pixel value of a character attribute pixel in the calculation is set to 0, or set smaller than a ratio of using a pixel value of an image attribute pixel. As a result, a change in the color of the color image surrounding the character can be prevented.

Abstract: Nozzles in a print head are arrayed in a density of 600 dpi. Moreover, a dither matrix has a size of 16 pixels×16 pixels in 600 dpi. The dither matrix is repeatedly used. In the meantime, each of rectangles represents an HS processing unit. WHS=3 pixels. As a consequence, the relationship of a least common multiple below is established in a nozzle array direction: 3×WD=16×WHS. In this case, the cycle of interference unevenness can be prolonged to the least common multiple between WD and WHS, that is, 48 pixels (3WD). In this manner, the size of the dither matrix is not an integral multiple of the HS processing unit width, so that the cycle of interference unevenness can be prolonged more than the size of the dither matrix. Thus, the interference unevenness can be hardly recognized.

Abstract: When an input image is shifted by 640 pixels from a test pattern with reference to the position of a nozzle, the remainder is obtained by dividing 640 pixels by pixels of the dither matrix in an x direction. For example, when the size of the dither matrix in the x direction is 256 pixels, the dither matrix is shifted by 128 pixels in a direction reverse to the x direction. In this manner, the phase of the dither matrix at the time of the quantization during test pattern printing matches the phase of the dither matrix at the time of the quantization during input image printing. Consequently, unevenness of the dither matrix at a position N becomes the same in both of the test pattern and the input image. The HS correction to density unevenness caused by the unevenness of the dither matrix becomes suitable for the input image.

Abstract: In order to print a unit area of a print medium by a first printing scan and a second printing scan, dither patterns are formed which can control the arrangement of dots on the print medium without adverse effects of density unevenness and graininess, that are caused by printing position displacement. Regarding first and second dither patterns, information indicating whether or not a threshold is already set to a reference pixel and one or more pixels around the reference pixel in the first dither pattern is obtained for cases where each pixel in the first dither pattern is the reference pixel. A pixel in the second dither pattern to which a predetermined pixel is to be set is determined based on the obtained information. The first and second dither patterns formed in the above manner are associated with the first printing scan and the second printing scan, respectively.

Abstract: One dither mask having a highest spacial frequency is selected from a plurality of dither masks. Next, a granularity is obtained with reference to a table based on the selected dither mask and an ejection amount level per area. Moreover, a difference in granularity between adjacent areas is calculated with respect to all of the areas. A maximum value is obtained out of the obtained differences in granularity, and then, the maximum difference in granularity is compared with a determination threshold. When the maximum difference in granularity is the threshold or greater, it is determined whether or not a dither mask having a spacial frequency lower than that of the selected dither mask is stored in a memory. When there are dither masks having lower spacial frequencies, a dither mask having a spacial frequency lower by one level than that of the selected dither mask is selected.

Abstract: As viewed for each processing unit in HS processing, a processing unit width is more than 1 pixel, so that threshold arrangement corresponding to a target quality of an image intended by a dither matrix is kept while a possibility of avoiding the zero number of dots from being generated can be enhanced. Moreover, the threshold arrangement is kept while a possibility of generating the same number of dots in processing units can be enhanced. Consequently, the threshold arrangement corresponding to a predetermined target quality of an image intended by a dither matrix is kept while it is possible to reduce occurrence of an uneven density caused by the HS processing. Thus, it is possible to prevent the threshold arrangement from being limited by the HS according to the degree of the reduction.

Abstract: Provided are an image processing apparatus and an image processing method capable of reducing color unevenness due to variations in ejection characteristics among a plurality of nozzles when printing an image using a plurality of inks. To that end, a first image which is made up a color with noticeable color unevenness and similar colors is printed onto a print medium. The user then specifies a color and a nozzle position where color unevenness has occurred. On the basis of these results, parameters are set for a correction table referenced by an MCS processor. In so doing, it becomes possible to address the factor causing the color unevenness, and mitigate the effects of color unevenness in a focused way without incurring increases in processor load, memory requirements, or processing time as compared to the case of calibrating all lattice points.

Abstract: An image processing apparatus includes an acquiring unit configured to acquire first image data representing gradation of a black character image, and second image data having a resolution lower than that of the first image data and representing gradation of a color image; a first generating unit configured to generate first dot data in accordance with a gradation value of each pixel in the first image data acquired by the acquiring unit; and a second generating unit configured to assign a number of dots to each pixel in the second image data, the number being greater than the maximum number of dots to be assigned by the first generating unit to each pixel in the first image data, and generating dot data for forming an image having an image attribute, in accordance with a gradation value of each pixel in the second image data acquired by the acquiring unit.

Abstract: Provided are an image processing apparatus and an image processing method capable of reducing color unevenness due to variations in ejection characteristics among a plurality of nozzles when printing an image using a plurality of inks. To that end, a first image which is made up a color with noticeable color unevenness and similar colors is printed onto a print medium. The user then specifies a color and a nozzle position where color unevenness has occurred. On the basis of these results, parameters are set for a correction table referenced by are MCS processor. In so doing, it becomes possible to address the factor causing the color unevenness, and mitigate the effects of color unevenness in a focused way without incurring increases in processor load, memory requirements, or processing time as compared to the case of calibrating all lattice points.

Abstract: An optical receiver including: a preamplifier capable of changing a conversion gain in accordance with a reception level of a received burst signal; a gain control circuit capable of switching between a fast time constant and a slow time constant; and a convergence determination circuit for outputting a time constant switching signal in accordance with a state of the gain control circuit (transient state or steady state) and a reset signal between the burst signals. This configuration can switch the time constant of the gain control circuit at an appropriate timing.

Abstract: A laser diode drive circuit includes a laser diode (LD), a modulation-current differential drive circuit, a bias-current differential drive circuit, a first inductance connected between an anode of the LD and a positive power source, a second inductance connected between a cathode of the LD and a negative-phase output terminal of the bias-current differential drive circuit, a first resistor connected to a connection point of the anode of the LD and the first inductance and connected to a negative-phase output terminal of the modulation-current differential drive circuit, and a second resistor connected to a connection point of the cathode of the LD and the second inductance and connected to a positive-phase output terminal of the modulation-current differential drive circuit, and a positive-phase output terminal of the bias-current differential drive circuit is connected to the connection point.

Abstract: An image processing apparatus for applying a color balance correction to input image data, comprises a first highlight color calculation unit which estimates a light source at the time of shooting from pixel values of the image data, converts color values of the image data based on a condition of the estimated light source at the time of shooting, and calculates a first highlight color; a second highlight color calculation unit which calculates a second highlight color from the image data; a third highlight color calculation unit which calculates a third highlight color based on a positional relationship between the first highlight color and the second highlight color on a color space; and a correction unit which attains the color balance correction by converting the pixel values of the image data using the third highlight color.

Abstract: An image processing apparatus includes an acquiring unit which acquires first image data indicating a first gray-scale value of an image having a first attribute and a second image data indicating a second gray-scale value of an image having a second attribute that is different from the first attribute, a correcting unit which corrects the first gray-scale value and the second gray-scale value acquired by the acquiring unit on basis of information on an ejection characteristic of a discharge head to different extents, the discharge head ejecting liquid to be used for forming the first image and the second image on a recording medium with dots.

Abstract: An image processing apparatus for applying a color balance correction to input image data, comprises a holding unit which holds information indicating a locus of a change in highlight color when a color temperature for image data is changed on a color space; a highlight color calculation unit which calculates a highlight color from the image data; a distance calculation unit which calculates a distance between the highlight color and the highlight color locus held in the holding unit on the color space; a reliability calculation unit which calculates a reliability for a value of the highlight color calculated by the highlight color calculation unit in accordance with the distance calculated by the distance calculation unit; and a color balance correction unit which applies the color balance correction to the image data using the highlight color and the reliability.

Abstract: An image processing apparatus for generating dot data to form an image by forming dots on a recording medium includes a receiving unit, a first, second, and third generating unit, and a correcting unit. The receiving unit receives first and second image data included in image data. The first generating unit generates, per the first image data, first ink color data representing a multi-valued signal value corresponding to an ink color. The second generating unit generates, per the second image data, second ink color data representing a multi-valued signal value corresponding to an ink color. The correcting unit corrects the signal value represented by the generated first and second ink color data. The third generating unit generates, per the first and second ink color data of which the signal values have been corrected, the dot data representing existence of formation of dots to form an image.

Abstract: A defect on the surface or in the surface layer of a moving material can be detected by using a method comprising steps of: heating the surface of the material, obtaining thermal image data of the surface of the material using an infrared thermography camera while the surface of the material is being heated up at the heating step or being cooled down after heating, and detecting the defect by calculating Laplacian with respect to temperature of the surface represented by the thermal image data. When the thermal image data is obtained while the material is being heated up, a heating device and the camera is arranged so that thermal energy emitted from the heating device is reflected by the material to come into the camera.

Abstract: An image processing apparatus for applying a color balance correction to input image data, comprises a holding unit which holds information indicating a locus of a change in highlight color when a color temperature for image data is changed on a color space; a highlight color calculation unit which calculates a highlight color from the image data; a distance calculation unit which calculates a distance between the highlight color and the highlight color locus held in the holding unit on the color space; a reliability calculation unit which calculates a reliability for a value of the highlight color calculated by the highlight color calculation unit in accordance with the distance calculated by the distance calculation unit; and a color balance correction unit which applies the color balance correction to the image data using the highlight color and the reliability.

Abstract: An image processing apparatus for applying a color balance correction to input image data, comprises a first highlight color calculation unit which estimates a light source at the time of shooting from pixel values of the image data, converts color values of the image data based on a condition of the estimated light source at the time of shooting, and calculates a first highlight color; a second highlight color calculation unit which calculates a second highlight color from the image data; a third highlight color calculation unit which calculates a third highlight color based on a positional relationship between the first highlight color and the second highlight color on a color space; and a correction unit which attains the color balance correction by converting the pixel values of the image data using the third highlight color.