US 6,212,303 B1Granted

Method and module system for high speed processing of item images

AssigneeNCR Corporation

InventorsWayne M. Doran, John E. Bray, Charles K. Pope, John O. G. Vieth

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Abstract

A system and method for processing image data from a document and for producing a compressed binarized version of the image data for transmission to or use by subsequent users. Processing of the image data is done in parallel after the scanning of the document is started but before the entire document is scanned. A splitter is used to divide a scan line of image data produced by an imager at the scan line into a plurality of channels, with each channel having at least one overlap area of pixels and with the overlap areas of pixels being used to avoid errors between channels. Thresholding and compression are performed by each one of the channels in parallel. The compression is performed in a direction which is perpendicular to the direction of scanning and conforms to a standard compression algorithm like CCITT Group 4.

Claims12

Dependent claims

A method of processing non-transposed image data derived from scanning a document using a document scanner, with the image data presented in the form of successive non-transposed scan lines of pixels, with said scan lines of pixels including a first non-transposed scan line of pixels and a last non-transposed scan line of pixels to be processed from scanning said document, said method comprising the steps of:

(a) splitting each non-transposed scan line of pixels into a plurality of processing channels;
with a predetermined number of pixels being located within each of said processing channels, and with each of said processing channels having overlap pixels assigned thereto at the time of said splitting, with said overlap pixels being located between extremities of said processing channels;
and
(b) initiating thresholding of the pixels in said processing channels in parallel after a predetermined number of successive non-transposed scan lines of pixels has been generated but before the entire document has been scanned using the document scanner with said thresholding using said overlap pixels when thresholding pixels in a processing channel near the extremities thereof;
said method also including the step of:
(c) compressing the thresholded pixels in each of the processing channels in parallel along a direction which is perpendicular to said successive non-transposed scan lines of pixels through using reference rows which are parallel to target rows of thresholded pixels, with each said target row of thresholded pixels having only one pixel from each one of said successive scan lines of pixels, with said splitting and compressing steps, in addition to said thresholding step, being initiated after said first scan line of pixels is generated but before said last line of pixels is derived from said scanning said document using the document scanner.

3 more elements

A method of processing non-transposed image data derived from scanning a document using a document scanner, said method comprising the steps of:

(a) scanning the document using the document scanner so as to produce successive non-transposed scan lines of pixels, with said scan lines of pixels including a first non-transposed scan line of pixels and a last non-transposed scan line of pixels to be processed from scanning said document;
(b) processing said pixels within a said scan line to generate a digital gray scale value for each of the pixels within the scan line;
(c) dividing each non-transposed scan line of pixels into a plurality of processing channels so that each processing channel comprises a predetermined number of the pixels in a said scan line, with each processing channel having a starting pixel and an ending pixel and also having a predetermined number of adjacent pixels next to the starting and ending pixels included therein, with said processing channels and said adjacent pixels being formed in a single dividing operation, with said dividing step including the step of attaching the adjacent pixels with their respective channels at said dividing step;
(d) selecting an examining window for use in thresholding the gray scale value for each of the pixels in the scan line so that the pixel to be thresholded appears in the center of the examining window as the examining window is moved along the pixels in a said processing channel associated with the scan line and the adjacent pixels are used for thresholding when the pixel to be thresholded is near the starting pixel or near the ending pixel in a scan line for the processing channel;
(e) thresholding each of the pixels in each of the processing channels in parallel as described in step (d) to generate thresholded pixels;
and
(f) compressing the thresholded pixels in each of the processing channels in parallel along a direction which is perpendicular to said non-transposed scan lines of pixels through using reference rows which are parallel to target rows of thresholded pixels, with each said target row of thresholded pixels having only one pixel from each one of said successive non-transposed scan lines of pixels, with said dividing, thresholding, and compressing steps being initiated after said first non-transposed scan line of pixels is generated but before said last non-transposed line of pixels is derived from scanning said document.

4 more elements

A system for processing non-transposed image data derived from scanning a document using a document scanner comprising:

a document scanner for scanning the document so as to produce successive non-transposed scan lines of pixels, with said scan lines of pixels including a first non-transposed scan line of pixels and a last non-transposed scan line of pixels to be processed from scanning said document using said document scanner;
means for processing said pixels within a said scan line to generate a digital gray scale value for each of the pixels within the scan line;
dividing means for dividing each non-transposed scan line of pixels into a plurality of processing channels so that each processing channel comprises a predetermined number of the pixels in a said scan line, with each processing channel having a starting pixel and an ending pixel and also having a predetermined number of adjacent pixels next to the starting and ending pixels included therein, said dividing means being effective to form said processing channels with the associated adjacent pixels in a single operation;
examining window means including an examining window having a center for use in thresholding the gray scale value for each of the pixels in the scan line for generating thresholded pixels so that the pixel to be thresholded appears in the center of the examining window as the examining window is moved along the pixels in a said processing channel associated with the scan line and the adjacent pixels are used for thresholding when the pixel to be thresholded is near the starting pixel or near the ending pixel in a processing channel of the scan line;
thresholding means for thresholding each of the pixels in each of the processing channels in parallel to generate thresholded pixels;
and
compressing means for compressing the thresholded pixels in each of the processing channels in parallel along a direction which is perpendicular to said non-transposed scan lines of pixels, with said compressing means utilizing reference rows to compress target rows containing said thresholded pixels, with said reference and target rows being perpendicular to said successive non-transposed scan lines of pixels, and with each said target row having only one thresholded pixel from each one of said successive non-transposed scan lines of pixels, with said dividing means, said thresholding means, and said compressing means initiating said dividing, thresholding, and compressing, respectively, after said first non-transposed scan line of pixels is generated but before said last non-transposed line of pixels is derived from scanning said document using the document scanner.

4 more elements

Dependencies are inferred from the claim text.