Abstract: A method and apparatus for identifying the position of lines in pixel image data comprising the steps of obtaining a horizontal projection of image density across a widthwisely extended portion of the image data, identifying non-empty regions on the basis of the horizontal projection, inspecting the horizontal projection in a vertical direction to locate a first non-empty region having a first height, inspecting the horizontal projection in the vertical direction to locate a next non-empty region having a second height, and connecting the first region and the next region if the first height is less than the second height and if a distance between the first region and the next region is less than the first height.

Abstract: A method for cutting character images from a line segment of pixel image data includes a first cutting layer step in which nontouching and nonoverlapping characters are cut from a line segment, and a second cutting layer step in which touching characters are cut from the line segment.

Abstract: A character recognition system or the like in which character identities are stored in accordance with a hierarchical order established during processing to separate text image areas from non-text image areas. To separate text image areas from non-text image areas, blocks of pixels are selected from pixel image data by outlining contours of connected components in the pixel image data, determining whether the outlined connected components include text units or non-text units, selectively connecting text units widthwisely to form text lines, and selectively connecting text lines vertically to form text blocks. After blocks of pixels have been so selected, text blocks are segmented into lines of pixel image data, and characters are cut from the lines of pixel image data so obtained. If desired, the characters may be cut by a two-step cutting process in which non-touching and non-overlapping characters are first cut out, and touching characters are then cut out.

Abstract: In a character recognition system or the like, method and apparatus for selecting blocks of pixels from pixel image data so as to permit identification and grouping of similarly-typed pixels, such as text-type pixels and non-text-type pixels. Pixel image data is inputted and, if the pixel image data is not binary image data then the pixel image data is converted into binary pixel image data. Blocks of pixel image data are selected by outlining contours of connected components in the pixel image data, determining whether the outlined connected components include text unit or non-text units based on the size of the outlined connected components, selectively connecting text units widthwisely to form text lines based on proximity of adjacent text units, and selectively connecting text lines vertically to form text blocks based on proximity of adjacent text lines and on the position of non-text units between text lines. A hierarchical tree is formed based on the outlined connected components.

Abstract: Method and apparatus for image enhancement involving smoothing and thinning input image data, segmenting adjacent characters in the smoothed and thinned data, and identifying a segmented character based on a comparison of the segmented character to a dictionary of characters. Smoothing and thinning may be provided by applying to each pixel of input image data a filter whose spread depends on variations in image intensity of surrounding pixels to obtain filtered image data, deriving inverted image data from first difference data of the filtered image data and multiplying the inverted image data and the filtered image data to obtain smoothed and thinned image data. The filters may be Gaussians whose spreads are inversely proportionate to variations in input image intensity plus a constant and the filters may be applied to the image data using a variably filled mask of filter values.