GB2195802A - Pattern recognition system - Google Patents
Pattern recognition system Download PDFInfo
- Publication number
- GB2195802A GB2195802A GB08622939A GB8622939A GB2195802A GB 2195802 A GB2195802 A GB 2195802A GB 08622939 A GB08622939 A GB 08622939A GB 8622939 A GB8622939 A GB 8622939A GB 2195802 A GB2195802 A GB 2195802A
- Authority
- GB
- United Kingdom
- Prior art keywords
- filter
- tool
- pattern recognition
- holographic
- pattern
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V10/00—Arrangements for image or video recognition or understanding
- G06V10/88—Image or video recognition using optical means, e.g. reference filters, holographic masks, frequency domain filters or spatial domain filters
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Multimedia (AREA)
- Theoretical Computer Science (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Holo Graphy (AREA)
Abstract
A three-dimensional object, 11, is illuminated by a source of coherent radiation, 9, and radiation scattered from the object is passed through a transform lens, 3, 5, and a holographic filter, 1, encoded with a reference pattern corresponding to an object to be recognised and detected by an array 7. <IMAGE>
Description
SPECIFICATION
Pattern recognition system
This invention relates to pattern recognition systems.
Pattern recognition systems are often used in, for example, robotics, for the recognition of such three dimensional objects as tools.
These systems include for example optical correlators in which an image of the tool to be recognised is formed and compared with a reference image, and edge enhancement system in which an image of the tool is modified to enable further optical processing of the image to be carried out. In either case it is necessary for the system to include a holographic filter, this taking the form of a matched spatial filter such as a Vander Lugt filter in the case of the correlator, and a high pass filter in the case of the edge enhancement system. Such systems thus suffer the disadvantage that it is generally necessary for them to include a spatial light modulator to produce the two dimensional coherent image of the tool necessary to address a holographic.
filter, spatial light modulators being relatively expensive components.
It is an object of the present invention to provide a pattern recognition system for the recognition of three dimensional objects, in which a holographic filter is incorporated in the system, but in which it is not necessary to provide a spatial light modulator.
According to the present invention a pattern recognition system for the recognition of a three dimensional object, the system incorporating a holographic filter, is characterised in that it includes a source of coherent radiation arranged to illuminate the object, and means for directing coherent radiation from the source scattered by the object onto the holographic filter for processing by the filter.
One pattern recognition system in accordance with the invention will now be described, by way of example only, with reference to the accompanying figure which is a schematic diagram of the system.
Referring to the figure, the system includes a frequency plane optical correlator comprising a Vander Lugt filter 1 holographically incoded with a reference pattern. The filter 1 is placed between two Fourier transform lenses 3 in the focal plane of each of the lenses 3, 5. A two dimensional detector array 7 is placed in the focal plane remote from the filter 1 of the lens 5. A single mode laser diode 9, whose function is described hereafter, is also provided.
In use of the system the single mode laser diode 9 is used to illuminate a tool 11 which it is required to recognise. Means (not shown) are provided for directing radiation from the laser diode 9 which has been scattered by the tool 11 through the transform lens 3 onto the filter 1. The filter 1 thus produces an output which is the product of the Fourier transform of the pattern of light which is scattered by and is thus representative of the tool 11 and is subsequently received by the filter 1, and the reference pattern. The spatial distribution of Hght-received by the detector array 7 is thus representative of the correlation between the pattern of light scattered by the tool and the reference pattern. By appropriate calibration it can thus be determined whether the tool 11 corresponds to a predetermined tool.
It will be appreciated that whilst the system described above by way of example, is an optical correlator comprising a Vander Lugt filter, the invention is also applicable to a correlator including a quantity of optically non-linear material, for example a single crystal of bismuth germanium oxide, such a correlator using the process of three wave mixing within the crystal to enable scattered coherent light from the object to be recognised to be compared to a variety of different reference patterns.
It will also be appreciated that whilst the invention is particularly applicable to optical correlators, it is also applicable to other pattern recognition systems incorporating holographic filters, for example systems including high pass filters for edge enhancement purposes.
1. A pattern recognition system for the recognition of a three dimensional object, the system incorporating a holographic filter characterised in that it includes a source of coherent radiation arranged to illuminate the object, and means for directing coherent radiation from the source scattered by the object onto the holographic filter for processing by the filter.
2. A system according to Claim 1 in which said filter is a Vander Lugt filter.
3. A system according to Claim 1 in which said filter is a high pass filter.
4. A pattern recognition system for the recognition of a three dimensional object substantially as hereinbefore described with reference to the accompanying drawing.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (4)
1. A pattern recognition system for the recognition of a three dimensional object, the system incorporating a holographic filter characterised in that it includes a source of coherent radiation arranged to illuminate the object, and means for directing coherent radiation from the source scattered by the object onto the holographic filter for processing by the filter.
2. A system according to Claim 1 in which said filter is a Vander Lugt filter.
3. A system according to Claim 1 in which said filter is a high pass filter.
4. A pattern recognition system for the recognition of a three dimensional object substantially as hereinbefore described with reference to the accompanying drawing.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB08622939A GB2195802A (en) | 1986-09-24 | 1986-09-24 | Pattern recognition system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB08622939A GB2195802A (en) | 1986-09-24 | 1986-09-24 | Pattern recognition system |
Publications (2)
Publication Number | Publication Date |
---|---|
GB8622939D0 GB8622939D0 (en) | 1987-01-14 |
GB2195802A true GB2195802A (en) | 1988-04-13 |
Family
ID=10604691
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB08622939A Withdrawn GB2195802A (en) | 1986-09-24 | 1986-09-24 | Pattern recognition system |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2195802A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2236418A (en) * | 1989-09-30 | 1991-04-03 | William Morton | Holographic logic device |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1305248A (en) * | 1970-07-23 | 1973-01-31 | ||
US4053228A (en) * | 1975-12-12 | 1977-10-11 | Michael Schiller | Finger identification |
US4174179A (en) * | 1977-08-24 | 1979-11-13 | Guy Indebetouw | Continuous feed holographic correlator for randomly oriented workpieces |
US4227805A (en) * | 1978-01-25 | 1980-10-14 | Michael Schiller | Finger identification apparatus and method |
EP0021982A1 (en) * | 1979-06-18 | 1981-01-07 | Omnium De Realisations Industrielles Et Commerciales | Method and device for the optical processing of objects through intercorrelation with rings |
GB2154331A (en) * | 1984-02-16 | 1985-09-04 | Standard Telephones Cables Ltd | Coherent light optical processor |
-
1986
- 1986-09-24 GB GB08622939A patent/GB2195802A/en not_active Withdrawn
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1305248A (en) * | 1970-07-23 | 1973-01-31 | ||
US4053228A (en) * | 1975-12-12 | 1977-10-11 | Michael Schiller | Finger identification |
US4174179A (en) * | 1977-08-24 | 1979-11-13 | Guy Indebetouw | Continuous feed holographic correlator for randomly oriented workpieces |
US4227805A (en) * | 1978-01-25 | 1980-10-14 | Michael Schiller | Finger identification apparatus and method |
EP0021982A1 (en) * | 1979-06-18 | 1981-01-07 | Omnium De Realisations Industrielles Et Commerciales | Method and device for the optical processing of objects through intercorrelation with rings |
GB2154331A (en) * | 1984-02-16 | 1985-09-04 | Standard Telephones Cables Ltd | Coherent light optical processor |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2236418A (en) * | 1989-09-30 | 1991-04-03 | William Morton | Holographic logic device |
Also Published As
Publication number | Publication date |
---|---|
GB8622939D0 (en) | 1987-01-14 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |