Abstract: Provided is an image forming apparatus in which one of developing units that respectively contain visible toners of black, yellow, magenta, and cyan other than the developing unit that contains the visible toner of black is replaced by a developing unit that contains a transparent fluorescent toner. Consequently, a document image can be expressed by the visible toner of black and a designated color which falls within a color reproduction range determined by two of the visible toners of yellow, magenta, and cyan, and an additional pattern which is an additional information image for preventing falsification and forgery can be printed on the document image with the use of the transparent fluorescent toner.

Abstract: Image data Rin, Gin, Bin are read out from an image on a document, on reception of light reflected by the image after being emitted from a first light source for irradiating the document with visible light. Image data RUV, GUV, BUV are read out from the image on the document, on reception of light reflected by the image after being emitted from a second light source for irradiating the document with ultraviolet light. A color correction process is performed by reading out color corrected imaged data from a color correction table which stores in advance color corrected image data, which are associated with a combination of (i) image data, which correspond to the image data Rin, Gin, Bin, and image data which correspond to the image data RUV, GUV, BUV. By this, it is possible that even in a case where an image on the document contains a fluorescent image, the fluorescent image be easily and accurately reproduced.

Abstract: The image processing apparatus of the present invention includes: a bit number correction process section for converting tones of binary image data into a maximum tone and a minimum tone of multilevel image data; a spatial filter section for performing a smoothing process on image data resulting from the bit number conversion; and an enlarging/reducing section for performing an interpolation process on the image data subjected to the smoothing process so that smoothness of tones of the image data is maintained, the image data subjected to the interpolation process being supplied to the image display device. This allows an image display device for displaying multilevel image data to display a preview image of binary image data without deteriorating the quality of image data.

Abstract: Provided is an image forming apparatus in which one of developing units that respectively contain visible toners of black, yellow, magenta, and cyan other than the developing unit that contains the visible toner of black is replaced by a developing unit that contains a transparent fluorescent toner. Consequently, a document image can be expressed by the visible toner of black and a designated color which falls within a color reproduction range determined by two of the visible toners of yellow, magenta, and cyan, and an additional pattern which is an additional information image for preventing falsification and forgery can be printed on the document image with the use of the transparent fluorescent toner.

Abstract: Image data Rin, Gin, Bin are read out from an image on a document, on reception of light reflected by the image after being emitted from a first light source for irradiating the document with visible light. Image data RUV, GUV, BUV are read out from the image on the document, on reception of light reflected by the image after being emitted from a second light source for irradiating the document with ultraviolet light. A color correction process is performed by reading out color corrected imaged data from a color correction table which stores in advance color corrected image data, which are associated with a combination of (i) image data, which correspond to the image data Rin, Gin, Bin, and image data which correspond to the image data RUV, GUV, BUV. By this, it is possible that even in a case where an image on the document contains a fluorescent image, the fluorescent image be easily and accurately reproduced.

Abstract: The image processing apparatus of the present invention includes: a bit number correction process section for converting tones of binary image data into a maximum tone and a minimum tone of multilevel image data; a spatial filter section for performing a smoothing process on image data resulting from the bit number conversion; and an enlarging/reducing section for performing an interporation process on the image data subjected to the smoothing process so that smoothness of tones of the image data is maintained, the image data subjected to the interporation process being supplied to the image display device. This allows an image display device for displaying multilevel image data to display a preview image of binary image data without deteriorating the quality of image data.

Abstract: An image processing device of the present invention is provided with four kinds of sub masks in total including two kinds in a main scanning direction and two kinds in a sub scanning direction, in a main mask constituted by a plurality of pixels including a target pixel. In the image display device, when determining a target pixel of an inputted image data, a difference in a total density of the two kinds of sub masks in a main scanning direction is added to a normalized difference in total density of the two kinds of sub masks in a sub scanning direction, and a resultant value is compared with a threshold value so as to determine if the target pixel is an edge area or not.

Abstract: An image processing device of the present invention includes a region separating section and a filter processing section. With respect to a picture signal which is read out after resolution thereof in a sub scanning direction has been converted, the region separating section computes maximum density difference and complexity as feature parameters indicative of a characteristic of each pixel in the picture signal. Additionally, with respect to the complexity which is dependent on a size of the resolution in the sub scanning direction, the region separating section carries out a correction in accordance with the size of the resolution in the sub scanning direction, and separates the picture signal into each region by using the maximum density difference and the corrected complexity. In accordance with the size of the resolution in the sub scanning direction and each region separated by the region separating section, the filter processing section performs suitable image processing of the picture signal.

Abstract: The image forming device according to the present invention performs resolution conversion processing or scaling processing of a binary image and outputs a processed image. The present image forming device is provided with an edge detecting section, which, during resolution conversion or scaling of the binary image, detects edges of the image and detects lengths and shapes of the edges, and with an interpolated/skipped line producing section, which performs resolution conversion processing or scaling processing based on the lengths and shapes of edges detected by the edge detecting section.

Abstract: An image forming apparatus of the present invention includes (i) an image interpolating section for calculating interpolation point and interpolation density of the interpolation point when subjecting a binary image to resolution conversion and scaling and (ii) an offset amount correcting section for giving an offset beforehand when the image interpolating section calculates the interpolation point. As a result, the image forming apparatus can comply with unrounded magnifications of other than integral multiples and a desirable image even with respect to a character image and a pseudo-halftone image.

Abstract: An image processing apparatus includes a pixel number transforming section for processing input image data composed of a plurality of regions, each being represented by a plurality of pixels with a pixel number transformation, by performing an interpolation or a decrimation on a pixel. It further includes a region decision value extracting section for extracting a region decision value of a region that a target pixel belongs to, based on characteristic amounts representing characteristics of a block composed of the target pixel and a plurality of pixels around the target pixel, each pixel of the image data being considered to be the target pixel. A controller controls a sequential order of a filtering process and pixel number transformation process to be applied to a region, based upon the transformation increasing or reducing a number of pixels in a region.

Abstract: The read out image data is stored in the mask memory in a predetermined mask unit, and binarized into binary value with a predetermined threshold in the binarizing circuit. The binarized image data is output to the main scanning direction-black pixel counting circuit and the sub scanning direction-black pixel counting circuit, respectively, to count black pixels in the main scanning direction and in the sub scanning direction, respectively. The largest value is determined by the comparator, and designated as the linkage degree. With the judging circuit, the area judgement of the character area, the photograph area and the dot area is performed based on the linkage degree.

Abstract: An image processing apparatus of the present invention is provided with a region separating section and an automatic adjusting section. The region separating section, upon receiving a reference document having a specified ratio of a character region, a photographic region, and a spot region, recognizes and separates the each region of the received document from one another. The automatic adjusting section (1) counts the number of pixels in each of the separated regions and (2) uses the number of pixels thus counted to change a density conversion table, a filter, or a region separation table so as to adjust the separated state of each region such that the number of pixels thus counted is substantially equal to the number of pixels of the region separation state, thereby improving the accuracy of region separation of the image processing apparatus and the image quality of a final image after it is processed with image processing.