Document matching and annotation lifting
First Claim
1. A method for matching an original document image with a copy image, the method comprising the operations of:
- (a) defining the original document image as an ensemble of blocks, each of the blocks having neighboring blocks;
(b) forming a mask for each of the blocks by dilating foreground pixels included in the block;
(c) searching for a best match in the copy image, for each of the blocks, using a first search window, by correlating pixels in the mask with pixels in a corresponding portion in the copy image, each of the best matches having a matching score;
(d) indicating each of the blocks as “
unmatched”
when the corresponding matching score is less than a matching threshold; and
(e) computing a displacement vector for each of the matched blocks.
5 Assignments
0 Petitions
Accused Products
Abstract
A method for matching an original document image with a copy image is disclosed. The original document image is defined as an ensemble of blocks, each of the blocks having neighboring blocks. A mask is formed for each of the blocks by dilating foreground pixels included in the block. A best match is searched in the copy image, for each of the blocks, using a search window, by correlating pixels in the mask with pixels in a corresponding portion in the copy image. Each of the best matches has a matching score. Each of the blocks is indicated as “unmatched” when the corresponding matching score is less than a matching threshold. A displacement vector is computed for each of the matched blocks.
-
Citations
27 Claims
-
1. A method for matching an original document image with a copy image, the method comprising the operations of:
-
(a) defining the original document image as an ensemble of blocks, each of the blocks having neighboring blocks;
(b) forming a mask for each of the blocks by dilating foreground pixels included in the block;
(c) searching for a best match in the copy image, for each of the blocks, using a first search window, by correlating pixels in the mask with pixels in a corresponding portion in the copy image, each of the best matches having a matching score;
(d) indicating each of the blocks as “
unmatched”
when the corresponding matching score is less than a matching threshold; and
(e) computing a displacement vector for each of the matched blocks. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A method for producing an annotation image from a copy image and a registered original document image, the method comprising the operations of:
-
(a) forming a first mask by dilating foreground pixels in the registered original document image;
(b) forming a first annotation image by using portion of the copy image that lies outside the first mask;
(c) forming a second mask by dilating the first mask;
(d) defining each of connected components located on the first annotation image in the space between the first mask and the second mask as a broken stroke end; and
(e) connecting each of the broken stroke ends to at least one other broken stroke end, the other broken stroke end being chosen in accordance with a line tracing protocol. - View Dependent Claims (15, 16, 17, 18, 19, 20)
-
-
21. A system for matching an original document image with a copy image, the system comprising:
-
(a) a partition module for defining the original document image as an ensemble of blocks, each of the blocks including foreground pixels;
(b) a mask forming module for forming a mask for each of the blocks by dilating the foreground pixels included in the block;
(c) a search module for searching for a best match in the copy image, for each of the blocks, by correlating pixels in the mask with pixels in a corresponding portion in the copy image, the search module assigning to each of the best matches a matching score, and indicating each of the blocks as “
unmatched”
when the corresponding matching score is less than a matching threshold; and
(d) a displacement computing module for computing a displacement vector for each of the matched blocks. - View Dependent Claims (22, 23, 24)
-
-
25. A system for producing an annotation image from a copy image and a registered original document image, the system comprising:
-
(a) an initial annotation image module, the initial annotation image module forming a first mask by dilating foreground pixels in the registered original document image, forming a first annotation image by using portion of the copy image that lies outside the first mask, forming a second mask by dilating the first mask, and defining each of connected components located on the first annotation image in the space between the first mask and the second mask as a broken stroke end; and
(b) a broken stroke repair module connecting each of the broken stroke ends to at least one other broken stroke end, the other broken stroke end being chosen in accordance with a line tracing protocol. - View Dependent Claims (26, 27)
-
Specification