A noise-reduction processing device including: a part that calculates an edge strength indicating the edge amount at the pixel of interest based on the pixel of interest and surrounding pixels that surround the pixel of interest; a part that discriminates the edge direction at the pixel of interest; a first filter-processing part that subjects the pixel of interest to smoothing processing along a direction that is based on a direction-discrimination result and outputs a first filter-processing result; a second filter-processing part that subjects the pixel of interest to smoothing processing producing a lower low-pass effect than that of the first filter-processing part and outputs a second filter-processing result and a part that synthesizes the first and second filter-processing results, with the ratio of the first filter-processing result increased as the edge strength becomes higher and the ratio of the second filter-processing result increased as the edge strength becomes lower.

A noise-reduction processing device including: a part that calculates an edge strength indicating the edge amount at the pixel of interest based on the pixel of interest and surrounding pixels that surround the pixel of interest; a part that discriminates the edge direction at the pixel of interest; a first filter-processing part that subjects the pixel of interest to smoothing processing along a direction that is based on a direction-discrimination result and outputs a first filter-processing result; a second filter-processing part that subjects the pixel of interest to smoothing processing producing a lower low-pass effect than that of the first filter-processing part and outputs a second filter-processing result and a part that synthesizes the first and second filter-processing results, with the ratio of the first filter-processing result increased as the edge strength becomes higher and the ratio of the second filter-processing result increased as the edge strength becomes lower.

Edge enhancement of a digital image can include using at least two signal processing paths to adjust a display-formatted pixel value to enhance the appearance of edges in displayed image data. A digital image can be filtered by producing an edge enhancement factor, α, per pixel from at least one look up table (LUT). Digital image data can also be adjusted using at least two signal processing paths, where the image data is adjusted if a pixel value and its neighboring pixel values are all within a smoothing range or where the pixel delta value is outside of a bad pixel range and its neighboring pixel delta values are all within the bad pixel range. In such cases, the image data can be adjusted by replacing the pixel value with an average or median value of the neighboring pixels.

An image processing device includes first image processing part, and first image processing part includes first pixel group setting part that sets plurality of first pixel groups which is set to correspond to first pixel, and which is disposed along in plurality of directions that form plurality of angles different from each other with respect to predetermined direction in first image or which is disposed along in predetermined direction in each of plurality of images obtained by moving first image by plurality of angles different from each other with respect to predetermined direction, first calculation part configured to calculate plurality of first candidate pixel values based on size of pixel value of pixel included in each of plurality of first pixel groups, and first pixel value setting part that sets pixel value of second pixel of second image based on plurality of first candidate pixel values.

A position of a first registration mark printed on a substrate during an earlier printing operation is detected. A second registration mark is printed on the substrate during a current printing operation at a position on the substrate relative to the first registration mark based on the detected position of the first registration mark and a correction factor. An alignment difference between the position of the first registration mark and the position of the second registration mark is measured. A new correction factor for a subsequent printing operation is calculated by weighting the measured alignment difference according to a difference between the measured alignment difference and a previous measured alignment difference.

An image forming apparatus, including: a light source including a plurality of light emitting points and configured to emit light beams; a photosensitive member configured to rotate in a rotation direction so that a latent image is formed thereon with the light beams; a rotary polygon mirror configured to rotate around a rotation axis and having a plurality of mirror faces each configured to deflect the light beams so that the photosensitive member is scanned with the light beams; a detector configured to detect temperature; and a correction unit configured to correct image data of an input image by using a deviation amount, in the rotation direction of the photosensitive member, of the light beams deflected by each of the plurality of mirror faces, wherein the correction unit obtains the deviation amount according to the temperature detected by the detector.

An image forming apparatus, including: a light source including a plurality of light emitting points and configured to emit light beams; a photosensitive member configured to rotate in a rotation direction so that a latent image is formed thereon with the light beams; a rotary polygon mirror configured to rotate around a rotation axis and having a plurality of mirror faces each configured to deflect the light beams so that the photosensitive member is scanned with the light beams; a detector configured to detect temperature; and a correction unit configured to correct image data of an input image by using a deviation amount, in the rotation direction of the photosensitive member, of the light beams deflected by each of the plurality of mirror faces, wherein the correction unit obtains the deviation amount according to the temperature detected by the detector.

An image reading apparatus includes an image data obtaining unit, a foreign material position information obtaining unit, and a separation processor. The image data obtaining unit obtains image data read from a document passing over a read area. The foreign material position information obtaining unit obtains foreign material position information read from the read area in which the document is not present. The separation processor separates the image data into plural objects including a background object, detects, by using the foreign material position information, a streak image portion caused by foreign material in the read area and included in the image data, and assumes a pixel of the streak image portion to belong to the background object if the pixel is present in the background object and has a pixel value equal to or smaller than a threshold determined in accordance with a representative value of the background.

A document type recognition apparatus includes an image region separation unit, a smoothing unit, an edge enhancement unit, a histogram creation unit, and a document type recognition unit. The image region separation unit outputs a signal indicative of each region obtained by separating an input image into a character region and a pattern region. The smoothing unit performs smoothing processing to remove halftone dots of a particular number of lines or greater in the pattern region of the input image. The edge enhancement unit outputs an image subjected to edge enhancement processing depending on an amount of edge on an edge portion of the character region in the input image subjected to the smoothing processing. The histogram creation unit creates a histogram of the image subjected to the edge enhancement processing. The document type recognition unit recognizes a document type of the input image by utilizing the histogram.

An image processing apparatus includes a memory and at least one processor or circuitry or a combination thereof. The memory is configured to store determination conditions. The at least one processor or circuitry or the combination thereof is configured to acquire image data and extract a feature element from the image data. The at least one processor or circuitry or the combination thereof is further configured to determine whether the extracted feature element satisfies conditions defined in the determination conditions. The at least one processor or circuitry or the combination thereof is further configured to set an area with reference to an extracted feature element satisfying the conditions based on the determination conditions. The at least one processor or circuitry or the combination thereof is further configured to set an attribute of the area based on the determination conditions.