Intelligent detection of text on a page
AssigneeElectronics for Imaging, Inc.
InventorRon J. Karidi
Life of this patent
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Abstract
A technique for segmenting an image into text areas and non-text areas in which an image is stored with the following information per pixel: gray scale intensity (4 bits) and an indication of whether the pixel is neutral or color (1 bit). The image, e.g. a scanned RGB image, is converted to 0-15 levels of intensity and has a neutral/color indication bit assigned to each pixel. The technique proceeds in three phases as follows: Tile the image by square blocks, e.g. 6×6 or 8×8 for 600 dpi images, and store information about each block in a buffer; sweep the buffer left to right three tile rows at a time and make a preliminary decision for every tile-block in the middle row; examine the decision made in the previous step in a context block, e.g. a 3×3 block, and make revisions if necessary.
Claims21
A method for segmenting an image into text areas and non-text areas, comprising the computer aided steps of:
- tiling said image by blocks;
- wherein each block is typed as to text content, ranked for intensity, and rated as neutral or color;
- storing information about each block in a buffer;
- sweeping said buffer a predetermined number of tile rows at a time;
- making a preliminary decision whether a portion of the image being swept is a text area or a non-text area of said image for every tile-block in a middle row of said sweep;
- examining said preliminary decision in a context block;
- making revisions to said preliminary determination as necessary based upon said examination step;
- and
- outputting image information which segments said image into text areas and non-text areas.
An apparatus for segmenting images into text and non-text areas, comprising:
- a buffer for storing input images;
- means for tiling said image in tile-blocks;
- means for determining an intensity value for each pixel in said image relative to a threshold level;
- means for classifying each tile-block as to text content type and intensity;
- and
- means for rating each tile-block as neutral or color.
A method for segmenting an image into text and non-text areas, comprising the steps of:
- tiling said image by blocks to classify pixel information therein;
- typing each tile-block for text content;
- ranking each tile-block for intensity;
- rating each tile block as neutral or color;
- sweeping said image to determine the identity of text areas and non-text areas therein;
- and
- revising said determination as necessary in accordance with a predetermined scheme.
Dependencies are inferred from the claim text.