Abstract: The inventive image processing apparatus takes steps of 1) dividing an image to be processed into numerals of blocks; 2) determining whether a block is a color block or not; 3) determining whether the image is a color image or not based on the rate of color blocks to the entire blocks. Thereby, valid color pixel rate can be obtained at blocks belonging to a color region even though an image is almost monochrome but partially colored. Accordingly, the inventive image processing apparatus can appropriately determine whether the image is a color image or not.

Abstract: In an image processing method, a tone of a target pixel and tones of peripheral pixels around the target pixel are detected. Also, a tone difference between the target pixel and each peripheral pixel is detected. Then, smoothing processing is executed upon image data of the target pixel, based on the tone differences between the target pixel and the peripheral pixels, in such a way as to reduce a change of the tone of the target pixel.

Abstract: The inventive image processing apparatus takes steps of 1) dividing an image to be processed into numerals of blocks; 2) determining whether a block is a color block or not; 3) determining whether the image is a color image or not based on the rate of color blocks to the entire blocks. Thereby, valid color pixel rate can be obtained at blocks belonging to a color region even though an image is almost monochrome but partially colored. Accordingly, the inventive image processing apparatus can appropriately determine whether the image is a color image or not.

Abstract: In an image processor which converts color image data to image data of cyan, magenta, yellow and black necessary for forming an image, a black character edge is discriminated in R, G, B image data. The edge component in a black character area is deleted by narrowing on image data of cyan, magenta and yellow. Further, in a black character area, K data is replaced with maximum density data in the R, G, B data, and edge emphasis is performed on the substituted data. Then, reproducibility of a thin line portion in a character is improved largely.

Abstract: The inventive image processing apparatus takes steps of 1) dividing an image to be processed into numerals of blocks; 2) determining whether a block is a color block or not; 3) determining whether the image is a color image or not based on the rate of color blocks to the entire blocks. Thereby, valid color pixel rate can be obtained at blocks belonging to a color region even though an image is almost monochrome but partially colored. Accordingly, the inventive image processing apparatus can appropriately determine whether the image is a color image or not.

Abstract: An image reading apparatus includes, with the purpose of detecting with improved precision noise generated due to dust on a platen, three line sensors spaced from each other in a sub scanning direction to scan an original in the sub scanning direction, the platen between the original and the three line sensors, a moving mechanism for moving the platen at a rate relative to the line sensors, the rate being different from that of the original relative to the line sensors, an interline corrector synchronizing three data output from the three line sensors to be values of pixels reading a single location on the original, and a noise detector receiving these data synchronized by the interline corrector that are provided successively line by line, and the noise detector includes an isolated noise determiner determining that an isolated point of a chromatic color is a noise pixel.

Abstract: An image reading apparatus includes: three line sensors; a mover moving a platen at a rate relative to the three line sensors; an interline corrector synchronizing the three line sensors' outputs to be a pixel having read a single location on an original; NOR and AND devices comparing three data corresponding to a single location on the original to detect a noise pixel; a determiner depending on a color of a pixel neighboring a pixel to be processed selected from pixels arranged in the main scanning direction, to determine first data from which a noise pixel is initially detected; and a determiner invalidating a noise pixel identical in location in the main scanning direction to the pixel to be processed, that is included in a line input prior to a line including the pixel detected from the first data and that is detected from data other than the first data.

Abstract: An image reading apparatus includes: three line sensors mutually spaced in a sub scanning,direction; a platen arranged between the original and the three line sensors; a mover moving the platen relative to the three line sensors at a rate relative to the three line sensors, the rate being different from that of the original relative to the three line sensors; a lightness difference detector extracting a feature pixel having a predetermined feature from each of three data output from the three line sensors; and NOR and AND devices comparing the three data corresponding to a single location on the original to detect the feature pixel extracted from one of the three data, as a noise pixel if the feature pixel is not a feature pixel for the other data.

Abstract: An image reading apparatus includes, with the purpose of detecting noise in an image due to dust on a platen, three line sensors, a platen between an original and the line sensors, a moving mechanism for moving the platen, a noise detection processor detecting noise pixels from multiple data output from the line sensors, an order determination unit determining the order in which the noise pixel is detected, based on the order in which the line sensors are arranged and the direction in which the platen is moved, and a noise length calculator predicting the noise length in the sub scanning direction based on the number of noise pixels successive in the main scanning direction, the original transport rate, the platen moving rate, and the distance between the line sensors.

Abstract: An image reading apparatus includes: three line sensors having filters, respectively, different in spectral sensitivity, and arranged in a subscanning direction with a distance therebetween to scan an original in the subscanning direction; a platen arranged between the original and the three line sensors; a mover moving the platen at a rate relative to the three line sensors, the rate being different from that of the original relative to the three line sensors; a noise pixel detection processor detecting a noise pixel from each of the three data output from the three line sensors; a color detector detecting a color of each noise pixel from the three data; and a determiner validating a result of detection by the noise pixel detection processor when a color of the noise pixel and that of a pixel neighboring the noise pixel form a predetermined combination.

Abstract: An image reading apparatus includes: three line sensors mutually spaced in a sub scanning direction; a platen arranged between the original and the three line sensors; a mover moving the platen relative to the three line sensors at a rate relative to the three line sensors, the rate being different from that of the original relative to the three line sensors; a lightness difference detector extracting a feature pixel having a predetermined feature from each of three data output from the three line sensors; and NOR and AND devices comparing a plurality of data corresponding to a single location on the original to detect the feature pixel extracted from one of the plurality of data, as a noise pixel if the feature pixel is not a feature pixel for the other data and also has at least a predetermined value in saturation.

Abstract: An image reading apparatus includes, with the purpose of accurately correcting noise in an image due to dust on a platen, three line sensors spaced from each other in a sub scanning direction to scan an original in the sub scanning direction, a platen between the original and the three line sensors, a moving mechanism for moving the platen, a noise detection processor detecting a noise pixel from each of multiple data output from the three line sensors, a second pixel extractor extracting a second pixel present in first data for correcting the noise pixel, based on a value of a first pixel present in second data different from the first data and corresponding to the same location on the original as the noise pixel, and a corrector correcting the noise pixel based on the extracted second pixel.

Abstract: An image reading apparatus includes, with the purpose of accurately correcting noise in an image due to dust on a platen, three line sensors spaced from each other in a sub scanning direction to scan an original in the sub scanning direction, a platen between the original and the three line sensors, a moving mechanism for moving the platen, a noise detection processor detecting a noise pixels from each of multiple data output from the three line sensors, a selector selecting one of a plurality of search ranges defined with reference to the noise pixel, and a corrector extracting a reference pixel for correcting the noise pixel from the selected search range to correct the noise pixel based on the value of the extracted reference pixel.

Abstract: An image reading apparatus includes: three line sensors mutually spaced in a sub scanning direction; a platen arranged between the original and the three line sensors; a mover moving the platen at a rate relative to the three line sensors, the rate being different from that of the original relative to the three line sensors; a first detector detecting a noise pixel based on a plurality of data output from the three line sensors; and a second detector detecting a subsequent noise pixel based on the noise pixel detected with the first detector.

Abstract: An image reading apparatus includes: three line sensors mutually spaced in a sub scanning direction; a platen arranged between the original and the three line sensors; a mover moving the platen at a rate relative to the three line sensors, the rate being different from that of the original relative to the three line sensors; a first lightness difference detector extracting a first feature pixel of a first level from each of three data output from the three line sensors; a second lightness difference detector extracting a second feature pixel of a second level; and NOR and AND devices comparing the three data corresponding to a single location on the original to detect the first feature pixel extracted from one of the three data, as a noise pixel if the second feature pixel is not extracted from the other data.

Abstract: An image reading device capable of detecting foreign particles on a transparent member by including the transparent member, a conveyance unit that conveys an original document to the transparent member, a reading unit that reads via the transparent member an image of the original document being conveyed on the transparent member at multiple reading positions that exist with a prescribed distance therebetween along an original document conveyance direction, an output unit that outputs signals for different color components corresponding to each of the reading positions, a transparent member moving unit that moves the transparent member in a prescribed direction such that the original document slides over the transparent member while being conveyed to the reading positions during image reading, and a detector that detects noise components caused by foreign particles on the transparent member based on the output signals from the output unit.

Abstract: The inventive image processing apparatus takes steps of 1) dividing an image to be processed into numerals of blocks; 2) determining whether a block is a color block or not; 3) determining whether the image is a color image or not based on the rate of color blocks to the entire blocks. Thereby, valid color pixel rate can be obtained at blocks belonging to a color region even though an image is almost monochrome but partially colored. Accordingly, the inventive image processing apparatus can appropriately determine whether the image is a color image or not.

Abstract: In order to prevent the appearance of gaps in fine lines when image data undergoes resolution conversion, the image processing apparatus includes an image reading unit that inputs image data, a fine line detection unit 113 that detects fine lines from the image data, a resolution conversion unit 111 that converts the image data to a prescribed resolution, and a fine line restoration unit 114 that restores fine lines in the image data that has undergone resolution conversion.

Abstract: An image processing system provided with a line sensor for reading image signals in line units. First, the line sensor scans a document in a normal direction. At this time the image data obtained by the scan are subjected to image processing such as compression and the like. Areas of image data that cannot be processed to the high moving speed of the scanner are subjected to image processing by later performing a scan in the reverse direction.

Abstract: An image processing apparatus reducing image noise caused at a device which has a stationary reading portion such as a CCD sensor and reads an image of a document by moving the document is structured as follows: the image processing apparatus determines whether full color image data read by the reading portion is out of a predetermined color space; it uses shift resisters to determine that the image data out of the predetermined color space continues in a sub scanning direction; and thus it detects a line-shaped dirt image caused by dirt or the like at the reading portion, and corrects the dirt image.