Pattern recognition and other inventions
First Claim
1. An apparatus for detecting the presence of one or more images of a known predetermined kind in a scene, comprising:
- means adapted to produce a scene image corresponding to a scene;
a digital input means comprising;
first electronic processing means adapted to process at least a part of the scene image to produce a scene pattern corresponding to the Fourier Transform of at least part of the scene image, storage means adapted to store one or more reference patterns, each reference pattern comprising the Fourier Transform of a respective reference image, second, processing means adapted to electronically combine the scene pattern with a reference pattern to produce a combined pattern; and
an optical output means adapted to produce an optical output that is derived from the combined pattern.
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Abstract
An apparatus for detecting the presence of one or more images of a known kind in a scene is disclosed which comprises a digital input means and an optical output means. The digital input means comprises a capture means which passes a capture image to a first electronic processing means to produce a scene pattern corresponding to a Fourier Transform of the scene image. This pattern is then digitally combined with one or more reference patterns corresponding to Fourier Transforms of a reference image. The resulting combined patterns are then used to modulate a beam of light which may be focused to perform an inverse Fourier Transform providing correlation information. In a preferred arrangement, the combined pattern is displayed on a spatial light modulator. A “smart” spatial light modulator is also disclosed which comprises an array of light modulating devices, each device comprising a detector and at least one pixel, whereby light incident upon the detector produces an output signal which is adapted to control the state of the modulating medium. By suitable processing, the “smart” SLM may be adapted to either attenuate light below a certain intensity or only light above a certain intensity to act as a saturable absorber.
73 Citations
55 Claims
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1. An apparatus for detecting the presence of one or more images of a known predetermined kind in a scene, comprising:
- means adapted to produce a scene image corresponding to a scene;
a digital input means comprising;
first electronic processing means adapted to process at least a part of the scene image to produce a scene pattern corresponding to the Fourier Transform of at least part of the scene image, storage means adapted to store one or more reference patterns, each reference pattern comprising the Fourier Transform of a respective reference image, second, processing means adapted to electronically combine the scene pattern with a reference pattern to produce a combined pattern; and
an optical output means adapted to produce an optical output that is derived from the combined pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45)
- means adapted to produce a scene image corresponding to a scene;
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46. A method of detecting the presence of one or more reference images in a scene comprising the steps of producing an image scene corresponding to at least part of a scene;
- processing at least a part of the captured image scene to produce a scene pattern corresponding to the Fourier Transform of the captured scene image;
electronically combining the scene pattern with at least one reference pattern corresponding to the Fourier Transform of a reference object to produce a combined pattern and producing an optical output derived by the combined pattern.
- processing at least a part of the captured image scene to produce a scene pattern corresponding to the Fourier Transform of the captured scene image;
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47. The combination of a smart spatial light modulator in conjunction with a camera, the smart spatial light modulator comprising an array of light modulating devices, each device comprising a light detector and at least one pixel of a modulating medium, in which the light detector is adapted to measure the intensity of light incident thereupon to produce a light-level output signal, which the output signal is adapted to control the modulating medium so as to either:
- (a) suppress low level light, or (b) moderate high level light.
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48. A method enabling a camera to integrate frames prior to readout comprising at least one detector in the path of a light beam, and at least one pixel of a modulating medium in the path of the light beam, and in the event that the output of the detector is below a predetermined threshold, controlling the modulation state of the pixel to absorb the incident light.
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49. A method of preventing blooming or saturation of a camera comprising providing at least one detector in the path of a light beam, and at least one pixel of a modulating medium in the path of the light beam, and in the event that the output of the detector is above a predetermined threshold controlling the modulation state of the pixel to attenuate light above a predetermined level.
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50. An optical pattern recognition and/or location apparatus comprising means for combining a scene pattern representative of the Fourier Transform of a scene image with a reference pattern representative of the Fourier Transform of a reference image to produce a combined pattern, means for combining a chirp patterns with either (a) the scene pattern, or (b) the reference pattern, or (c) the combined pattern with a chirp signal to produce a chirped combined pattern (a combined patterns that has been influenced by the chirp), a spatial light modulator adapted to display the combined pattern, a light source adapted to emit a beam of light which is modulated by the spatial light modulator, and a monitoring means adapted to monitor the modulated light beam to detect the presence and/or location of the reference images in the scene image.
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51. An optical assembly comprising:
- at least two light emitting devices and a lens, each light emitting device being spaced at a different position relative to the optical axis of the lens;
a controller adapted to control the illumination of each device sequentially; and
a spatial light modulator provided between the light emitting devices and an output detector array adapted to receive light which has been modulated by the SLM.
- at least two light emitting devices and a lens, each light emitting device being spaced at a different position relative to the optical axis of the lens;
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52. A method of detecting the presence of and/or location of a reference object in a scene comprising the steps of:
- illuminating the scene by transmitting at least one pulse of electromagnetic radiation;
producing a captured scene image corresponding to the reflected radiation received at a predetermined time after the pulse of radiation is transmitted;
processing at least a part of the captured scene image to produce a scene pattern corresponding to the Fourier Transform of the captured scene image; and
electronically combining the scene pattern with at least one reference pattern corresponding to the Fourier Transform of a reference image to produce a combined pattern.
- illuminating the scene by transmitting at least one pulse of electromagnetic radiation;
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53. A method of detecting the presence and/or location of a reference object in a scene comprising the steps of:
- producing at least two combined pattern masks by combining at least one scene pattern with at least one reference pattern; and
displaying said at least two masks simultaneously on a spatial light modulator.
- producing at least two combined pattern masks by combining at least one scene pattern with at least one reference pattern; and
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54. A method of reducing the time required to maintain a net zero voltage across each pixel of an SLM to prevent dissociation of the liquid crystal molecules of the SLM comprising the steps of:
- generating a number of patterns to be displayed on the spatial light modulator (a list of patterns), establishing the net integrated voltage bias effect on each pixel of the SLM created by displaying the list of patterns, and applying to each pixel an opposite list correction voltage of substantially the same magnitude as the integrated voltage applied to that pixel by displaying the list of patterns so that the net integral voltage applied to each pixel after the integrated voltage is substantially zero.
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55. A method of controlling the alignment of an alignable member with a desired scene object, the method comprising taking a scene image which contains the object, Transforming the scene image to obtain a binarised Fourier Transform scene pattern, combining the scene pattern with a binarised Fourier Transform of a reference patterns corresponding to a reference object which matches the scene object to create a binarised combined pattern, inverse Fourier Transforming the binarised combined pattern to produce a correlation output having at least two correlation peaks, and controlling the alignment of the alignable member with the scene object so as to bring the correlation peaks towards each other, preferably making them substantially coincident.
Specification