Method and apparatus for locating a two-dimensional symbol using a double template
First Claim
1. A computer-implemented method for locating the position of an imaged acquisition target in a pixel image, comprising the following steps:
- (a) generating image signals corresponding to said image with a camera, said image comprising said imaged acquisition target;
(b) comparing said image signals with template signals corresponding to a double template at a plurality of positions within said image using a processor, said double template corresponding to an ideal acquisition target, wherein said double template comprises two identical halves; and
(c) locating the position of said imaged acquisition target in said image using the processor in accordance with said comparisons of step (b).
0 Assignments
0 Petitions
Accused Products
Abstract
In a method and apparatus for locating the acquisition target of a two-dimensional symbol in a pixel image, the image is convolved with a double template. The position with the greatest correlation coefficient between the double template and the image is selected as the location of the acquisition target. The double template comprises two identical parallel one-dimensional single templates corresponding to two lines that cross the symmetrical acquisition target at equal distances from the center of the acquisition target. Using a double template instead of only a single template reduces the possibility of finding false positive locations of the acquisition target. Since the double template comprises two identical halves, the image is preferably convolved with only one half of the double template and the double-template correlation coefficients are then generated from these intermediate single-template correlation results. In a preferred embodiment, a binary pixel image is run-length encoded prior to being convolved with a run-length-encoded template.
-
Citations
44 Claims
-
1. A computer-implemented method for locating the position of an imaged acquisition target in a pixel image, comprising the following steps:
-
(a) generating image signals corresponding to said image with a camera, said image comprising said imaged acquisition target; (b) comparing said image signals with template signals corresponding to a double template at a plurality of positions within said image using a processor, said double template corresponding to an ideal acquisition target, wherein said double template comprises two identical halves; and (c) locating the position of said imaged acquisition target in said image using the processor in accordance with said comparisons of step (b). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. An apparatus for locating the position of an imaged acquisition target in a pixel image, comprising:
-
(a) a camera for generating image signals corresponding to said image, said image comprising said imaged acquisition target; and (b) a processor for comparing said image signals with template signals corresponding to a double template at a plurality of positions within said image, said double template corresponding to an ideal acquisition target, wherein said double template comprises two identical halves; and
for locating the position of said imaged acquisition target in said image in accordance with said comparisons. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. A computer-implemented method for locating the position of an imaged acquisition target in a pixel image, comprising the following steps:
-
(a) generating image signals corresponding to said image with a camera, said image comprising said imaged acquisition target; (b) comparing said image signals with template signals corresponding to a double template at a plurality of positions within said image using a processor, said double template corresponding to an ideal acquisition target, wherein at least one half of said double template does not correspond with a center of said ideal acquisition target; and (c) locating the position of said imaged acquisition target in said image using the processor in accordance with said comparisons of step (b). - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
-
-
34. An apparatus for locating the position of an imaged acquisition target in a pixel image, comprising:
-
(a) a camera for generating image signals corresponding to said image, said image comprising said imaged acquisition target; and (b) a processor; for comparing said image signals with template signals corresponding to a double template at a plurality of positions within said image, said double template corresponding to an ideal acquisition target, wherein at least one half of said double template does not correspond with a center of said ideal acquisition target; and for locating the position of said imaged acquisition target in said image in accordance with said comparisons. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
-
Specification