Seiko Epson Corporation

Toshiyuki Hattori

Takeshi Miyashita

Kiyoaki Murai

Sunao Murata

Tetsuya Suzuki

Shinji Nozawa

Noriyoshi Chiba

Toshiaki Isobe

Ryuji Oomoto

A scan target is scanned to acquire scan data that includes tone values for each color component in a plurality of pixels; there are acquired scan profiles indicating association relationships between the aforementioned tone values and color values, which profiles specify a said association relationship for each of a plurality of scan locations in the aforementioned image scanning program code; and for scan data acquired by means of the aforementioned image scanning step, the aforementioned tone values are converted to color values with reference to the scan profile corresponding to each scan location.

Highly accurate and rapid scanning by a simple scanning device and color correction technology for a printing device

There is generated a virtual tile set which virtually covers color planes of an original image without any clearance or overlap by combination of Penrose-type virtual tiles to be non-periodically provided on the planes. The respective tiles are subjected to raster conversion in accordance with predetermined gradation levels, thereby generating a raster image. Since the virtual tiles can be laid non-periodically, iteration of the same dot pattern on the raster image can be prevented.

Processor for image processing, method of processing image using the same, and printer incorporating the same

When a screen for halftoning of N&times;N pixel size is realized, gamma conversion cells, the number of which is N, are prepared for converting a pixel value of one pixel into a dot signal. When these N gamma conversion cells are repeatedly applied to N&times;N pixels by a predetermined order pattern, dots are respectively grown round N growing cores on the screen of N&times;N pixels.

Halftoning device and image forming apparatus

To convert gray-scale data of each pixel of image data into pulse-width data for each pixel, a RAM is provided. The RAM has nine pixel memory regions corresponding to nine pixels a to i for forming, for example, a 3&times;3 pixel matrix on the output image. In each of the pixel memory regions, there are stored pulse-width data items corresponding to values which are permitted for gray-scale data to have. Pulse-width data items in the pixel memory regions are slightly different from one another among pixel memory regions. Gray-scale data of each pixel of image data and address word composed of gray-scale data of each pixel of image data and coordinates of each pixel in the 3&times;3 matrix is supplied to the RAM. Thus, pulse-width data corresponding to gray-scale data is read from the pixel memory region so that a laser drive pulse having a pulse width corresponding to the read pulse-width data is generated.

Apparatus for generating pulse-width data for toner-transfer-type printing apparatus

To convert gray-scale data of each pixel of image data into pulse-width data for each pixel, a RAM is provided. The RAM has nine pixel memory regions corresponding to nine pixels a to i for forming, for example, a 3.times.3 pixel matrix on the output image. In each of the pixel memory regions, there are stored pulse-width data items corresponding to values which are permitted for gray-scale data to have. Pulse-width data items in the pixel memory regions are slightly different from one another among pixel memory regions. Gray-scale data of each pixel of image data and address word composed of gray-scale data of each pixel of image data and coordinates of each pixel in the 3.times.3 matrix is supplied to the RAM. Thus, pulse-width data corresponding to gray-scale data is read from the pixel memory region so that a laser drive pulse having a pulse width corresponding to the read pulse-width data is generated.

Printing system, printer, printer driver and program storage medium

A CPU converts data received from a host device into binary image data and compresses the data, and thereafter writes the compressed data into an image buffer in a RAM. In this compression, a method is employed in which, in a manner similar to the Huffman code compression method, an attention-directed byte is compressed on the basis of a correlation between the byte and a preceding byte. The compressed image data are DMA-transferred to a reconstruction/smoothing circuit. The reconstruction/smoothing circuit is configured by adding logic circuits for reconstruction to a smoothing circuit known in the conventional device, and reconstructs the compressed data by using a circuit which is in the smoothing circuit and which holds a preceding byte, or by referencing the held preceding byte.

Reconstruction device for compressed binary image data

An image processing system and method for laser-printing a composite image containing a monotone image and a multi gradation-level image in a superposed fashion such that the contours of characters in the monotone image are well smoothed without degrading the multi gradation-level image. The multi gradation-level image remains a faithful reproduction of the original and the resultant composite image is improved. When receiving a composite image 2, an image processing system binarize the pixel values of the composite image 2, to reproduce a mono-tone image 8. At the same time, the system generates a multi gradation-level, N-fold density image 10 from the composite image 2. The mono-tone image 8 is subjected to a smoothing process to smooth the contours of characters. The pixels corresponding to a corrected pixel area 17 in the mono-tone image 8 of the N-fold density image 10 are converted into white pixels by masking the corrected pixel area. Thereafter, the smoothed monotone image 16 and the N-fold density image 18 are superposed one on the other, to thereby form a final image 22.

Image processing system and method

When an N-times density binary image having N+1 tones is compressed, only the tone of each pixel is converted into a compressed code. The compressed code has a number of bits necessary and sufficient to distinguish between the tones. When a triple-density image having 4 tones is compressed, for example, the tone of each pixel is converted into a 2-bit compressed code. When the original N-times density is restored from the compressed code, there is formed a dot pattern in which the number of dots corresponding to the tone, as represented by the compressed code of each pixel, are situated closer to the darker one of the two adjoining pixels.

Apparatus and method for compressing and restoring binary image having

An image forming apparatus that is capable of saving developing agents such as toner and ink by reducing the number of dots in an image while ensuring that the characters and figures in the image are nonetheless represented distinctly. Bit map data is read out from buffer 23 and a set of three-pixel bits are held in both a vertical and a horizontal direction, with the pixel of interest being located in the center. On the basis of this set of bits, upper/lower edge detector circuit 59 and right/left edge detector circuit 61 determine whether the pixel of interest is positioned in any one of the edges of the pattern in the image to be printed. Additionally, dot-saved pattern generator circuit 67 performs dot reduction on the bit for the pixel of interest. The edge detection signals from the edge detector circuits 59 and 61 are supplied to OR gate 65, where they are ORed with the bit for the pixel of interest that is supplied from the dot-saved pattern generator circuit 67 after dot reduction. The logic sum signal from OR gate 65 represents bit map data which, as compared with the initial bit map data, has the edges of the pattern left intact and has the internal region of the pattern subjected to dot reduction. Printing is executed using this logic sum signal.

Growing community of inventors

Nagano, Japan

Toshiyuki Hattori