US5373147A
Expired / Lapsed
US
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Apparatus and method for detecting line segment direction
Assignee: International Business Machines Corp
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Filing: 1993-09-15
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Granted: 1994-12-13
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Expires: 2013-09-15
Abstract
Abstract An apparatus and method for reading, at high speed and with high precision, an angle of an angular modulation bar code directly from a multilevel brightness image of the bar code without the need for subjecting the image to preprocessing, such as binarization (conversion to a black-and-white image). The apparatus includes: means for dividing a multilevel brightness image of a bar code into a plurality of small sampling regions having the same area; means for detecting a maximum brightness value and a minimum brightness value among brightness values of pixels in each of the small sampling regions; means for setting a measurement origin and a threshold of light and dark in each of the small regions on the basis of the maximum and minimum brightness values; means for measuring a length from the measurement origin to a point where the brightness of the pixel reaches the threshold of light and dark in each of the small regions; means for accumulating, for each direction, length values measured in all the small regions, and for judging a direction having a maximum accumulated length value to be the bar code direction.
Inventors
- 👤 Masashi Noda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:48
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10544; G06K7/10821; G06K7/1093; G06K7/14; G06K7/1404; G06K7/1439; G06K7/1443; G06K7/1456
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
184 words
An apparatus for detecting the direction of a line segment in a multilevel brightness image, comprising: brightness detecting means for detecting brightness of a pixel in said image; means for selecting, from said image, a plurality of small sampling regions, each region having approximately the same area; means for detecting a maximum brightness value and a minimum brightness value among brightness values of the pixels in each of said small regions; means for setting a threshold of light and dark for each of said small regions on the basis of said maximum and minimum brightness values; means for setting a measurement origin in each of said small regions on the basis of said maximum and minimum brightness values; means for measuring a length from said measurement origin to a point where the brightness of the pixel reaches said threshold of light and dark for all directions in each of said small regions; and means for accumulating, for each direction, length values measured in said respective small regions and for selecting a direction having a maximum accumulated length value to be said line segment direction.
Claim 2
Independent Claim
184 words
An apparatus for detecting the direction of a line segment in a multilevel brightness image, comprising: brightness detecting means for detecting brightness of a pixel in said image; means for selecting, from said image, a plurality of small sampling regions, each region having approximately the same area; means for detecting a maximum brightness value and a minimum brightness value among brightness values of the pixels in each of said small regions; means for setting a threshold of light and dark for each of said small regions on the basis of said maximum and minimum brightness values; means for setting a measurement origin in each of said small regions on the basis of said maximum and minimum brightness values; means for measuring a length from said measurement origin to a point where the brightness of the pixel reaches said threshold of light and dark for all directions in each of said small regions; and means for accumulating, for each direction, length values measured in said respective small regions and for selecting a direction having a maximum accumulated length value to be said line segment direction.
Claim 3
Dependent Claim
13 words
The apparatus of claim 1, further comprising means for generating said multilevel image.
Claim 4
Independent Claim
150 words
A method for detecting the direction of a line segment in a multilevel brightness image, comprising the steps of: selecting, from said image, a plurality of sampling regions, each region having approximately the same area; detecting a maximum brightness value and a minimum brightness value among brightness values of pixels in each of said regions; selecting a threshold of light and dark for each of said regions in accordance with maximum and minimum brightness values; setting a measurement origin in each of said regions in accordance with said maximum and minimum brightness values; measuring a length from said measurement origin to a point where brightness of the pixel reaches said threshold of light and dark for all directions in each of said regions; accumulating, for each direction, length values measured in said respective regions; and selecting a direction having a maximum accumulated length value to be said line segment direction.
Claim 5
Independent Claim
150 words
A method for detecting the direction of a line segment in a multilevel brightness image, comprising the steps of: selecting, from said image, a plurality of sampling regions, each region having approximately the same area; detecting a maximum brightness value and a minimum brightness value among brightness values of pixels in each of said regions; selecting a threshold of light and dark for each of said regions in accordance with maximum and minimum brightness values; setting a measurement origin in each of said regions in accordance with said maximum and minimum brightness values; measuring a length from said measurement origin to a point where brightness of the pixel reaches said threshold of light and dark for all directions in each of said regions; accumulating, for each direction, length values measured in said respective regions; and selecting a direction having a maximum accumulated length value to be said line segment direction.
Claim 6
Dependent Claim
15 words
The method of claim 3 further comprising the step of generating said multilevel brightness image.
References Cited (Backward Citations)
US5276315A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-12-12 | 1998-06-13 | 1998-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-12 | 2002-06-13 | 2002-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-12 | 2006-06-13 | 2006-12-13 | $7700.00 | Window Closed / Lapsed |