Abstract: A line segment detector comprises a vertical line detecting part, a horizontal line detecting part, a left-to-right downward slanting line detecting part, a left-to-right upward slanting line detecting part, and a line-segment detecting/synthesizing section that calculates OR operation of output values from the vertical line detecting part, the horizontal line detecting part, the left-to-right downward slanting line detecting part, and the left-to-right upward slanting line detecting part. The line segment detector further comprises a re-determining unit comprising a second line-segment detecting part that sets a window to the detection result near the target pixel, counts the number of pixels whose detection result is determined as the line segment in the set window, determines, when the counted value is not smaller than a predetermined threshold value, that the pixel is a line segment.

Abstract: A processor performs layout analysis, and classifies pieces of bitmap data into a character area and a picture area. The processor divides each of the character area and the picture area into a plurality of tiles having a predetermined shape, thereby creating a table including information representing either character attribute or picture attribute in association with each tile number. The processor performs scalar quantization for data of each tile using a quantization coefficient for characters or pictures, based on the created table. The processor encodes the data of each tile using an SNR progressive technique or a resolution progressive technique, and performs post quantization for the data using a quantization parameter for characters or pictures. Then, the processor stores the encoded data into a storage device.

Abstract: A line segment detector comprises a vertical line detecting part, a horizontal line detecting part, a left-to-right downward slanting line detecting part, a left-to-right upward slanting line detecting part, and a line-segment detecting/synthesizing section that calculates OR operation of output values from the vertical line detecting part, the horizontal line detecting part, the left-to-right downward slanting line detecting part, and the left-to-right upward slanting line detecting part. The line segment detector further comprises a re-determining unit comprising a second line-segment detecting part that sets a window to the detection result near the target pixel, counts the number of pixels whose detection result is determined as the line segment in the set window, determines, when the counted value is not smaller than a predetermined threshold value, that the pixel is a line segment.

Abstract: A processor performs layout analysis, and classifies pieces of bitmap data into a character area and a picture area. The processor divides each of the character area and the picture area into a plurality of tiles having a predetermined shape, thereby creating a table including information representing either character attribute or picture attribute in association with each tile number. The processor performs scalar quantization for data of each tile using a quantization coefficient for characters or pictures, based on the created table. The processor encodes the data of each tile using an SNR progressive technique or a resolution progressive technique, and performs post quantization for the data using a quantization parameter for characters or pictures. Then, the processor stores the encoded data into a storage device.

Abstract: A processor performs layout analysis, and classifies pieces of bitmap data into a character area and a picture area. The processor divides each of the character area and the picture area into a plurality of tiles having a predetermined shape, thereby creating a table including information representing either character attribute or picture attribute in association with each tile number. The processor performs scalar quantization for data of each tile using a quantization coefficient for characters or pictures, based on the created table. The processor encodes the data of each tile using an SNR progressive technique or a resolution progressive technique, and performs post quantization for the data using a quantization parameter for characters or pictures. Then, the processor stores the encoded data into a storage device.

Abstract: An apparatus for pattern matching encoding includes a pattern extracting unit for extracting patterns in input binary or multi-level image data, an accumulating/match-checking unit for accumulating each extracted pattern and executing a match-check thereof with patterns that have been accumulated, a line segment checking unit for checking each pixel in the match pattern or the extracted pattern as to which line segment in directions the pixel is positioned on, and an encoding unit for encoding the extracted pattern by selecting a template having an optimum form according to the result of the line segment checking. The codes in pattern matching encoding are reduced, and the efficiency of code transmission and code accumulation is improved.

Abstract: A coding method and a coding apparatus for bi-level document image which makes a high speed coding processing possible is provided. In the coding apparatus, an image reading processing section provides an image data reading means which reads bi-level image data from a RAM, a CX generating means which generates CX using image data in a line memory and a CX counting means which counts the number of appearance times of CX based on the CX generated by the CX generating means and the inputted bi-level image data. In the coding apparatus, a coding processing section provides a coding processing deciding means which decides to implement either of two kinds of coding processing, a normal coding means which implements a normal coding processing implementing a conventional JBIG algorithm and a high speed coding means which implements a high speed coding processing using the counted values.

Abstract: A processor performs layout analysis, and classifies pieces of bitmap data into a character area and a picture area. The processor divides each of the character area and the picture area into a plurality of tiles having a predetermined shape, thereby creating a table including information representing either character attribute or picture attribute in association with each tile number. The processor performs scalar quantization for data of each tile using a quantization coefficient for characters or pictures, based on the created table. The processor encodes the data of each tile using an SNR progressive technique or a resolution progressive technique, and performs post quantization for the data using a quantization parameter for characters or pictures. Then, the processor stores the encoded data into a storage device.

Abstract: In a projection means black pixel histograms of a binary stationary image are generated in both the vertical and the horizontal direction. In a text type judgment means, in accordance with these histograms, a determination is made of whether the image is vertical text or horizontal text. Based on the result of this determination, a pattern block extraction means extracts either a column or a row from the image. The block is further projected and divided into smaller blocks. Then projection is again applied to these divided blocks and patterns are extracted by a pattern extraction means. A judgment is made as to whether or not joining of the extracted patterns is to be performed and, if joining is required, they are joined by a pattern joining means and finally the offsets of all the extracted patterns are calculated, whereupon data (of extracted patterns) are sent to a pattern matching process.

Abstract: A pattern matching encoding device for executing pattern matching encoding of binary still images and a pattern matching decoding device corresponding to the pattern matching encoding device are proposed. In the pattern matching encoding, each input pattern extracted from the input image is matched against library patterns in the library, and the input pattern is encoded using a matched library pattern as a reference pattern if the matched library pattern is found. The pattern matching encoding device comprises a pattern segmentation section for segmenting each of selected library patterns and the input pattern into two or more parts and thereby generating segmented library patterns and segmented input patterns, a matching section for matching each of the segmented input patterns against corresponding segmented library patterns, and a pattern combination section for generating a new library pattern by combining the segmented library patterns each of which has matched one of the segmented input patterns.

Abstract: Pattern encoding is carried out by 1) substituting an index data of a registered pattern for a position data in a library with respect to an index data peculiar to each of the extracted patterns, 2) taking a difference between an off-set position data of the extracted pattern and an off-set position data of the registered pattern whereby an off-set position difference data is provided, and 3) encoding the position data and the off-set position difference data and providing an encoded data. A pattern extracting unit obtains the extracted patterns from image data. An accumulating/checking unit accumulates the extracted patterns as accumulated patterns, assigns indexes specific to the accumulated patterns, and checks each extracted pattern by comparison with the accumulated patterns. When an accumulated pattern is found to match the extracted pattern, the accumulating/checking unit provides a position data within a library instead of the index data, and also provides the off-set position difference data.

Abstract: In a method and an apparatus for pattern matching encoding disclosed a font bit map library is provided separately from a temporary updating library, in which temporary bit map pattern data capable of being updated according to a character pattern cut out from input binary image data is stored. In the font bit map library is stored font bit map library pattern data of an input character pattern font or a font designated by the user. A pattern matching process on the character pattern, is executed by comparing the character pattern with temporary bit map pattern data and font bit map pattern data. The character pattern is newly registered in the temporary updating library, when it is judged as being matched with only the temporary bit map pattern or as being matched with neither of the temporary bit map pattern or the font bit map pattern. It is possible to improve data compressibility without sacrifice in image quality.

Abstract: In printing a pseudo half tone image, the pulse width of an image data pulse is reduced, so that when isolated dots in the image are printed, the isolated dot part become whitish and repeatability may be lowered. A region division section judges whether the data are binary data of characters or the pseudo half tone image data. For the pseudo half tone image data, a dot pattern identification section discriminates consecutive dots from isolated dots. An image data pulse control section controlls the pulse width of the image data pulse in accordance with the result of the identification. A printer engine performs print as output with each dot of which dimension is dependent on the controlled pulse width. Therefore when the image with characters and pictures mixed together is output, the printing as output can be performed in accordance with the character region and the pseudo half tone image region.