US7245764B2
Expired / Lapsed
US
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Image processing method and image processing apparatus utilizing luminance histograms, and projector
Assignee: Seiko Epson Corp
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Filing: 2003-06-11
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Granted: 2007-07-17
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Expires: 2023-06-11
Abstract
Abstract The invention provides an image processing method, an image processing apparatus, and a projector which determine a scene-change so as to perform an optimal tone conversion, luminance correction, or the like, for each scene of a moving image. An image processing apparatus includes a normalized-luminance-histogram computing unit to compute a normalized luminance histogram for each frame, histogram buffers to store normalized luminance histograms of respective comparing frames, a scene-change-detecting reference-value computing unit to compute scene-change-detecting reference values α and β corresponding to correlations between two normalized luminance histograms of the first and second frames respectively stored in the histogram buffers, and a scene-change determining unit to determine whether a change in scenes between images of the first and second frames has occurred or not, in accordance with the scene-change-detecting reference values α and β.
Inventors
- 👤 Masato Nishizawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:22
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/2007; H; H04; H04N; H04N5/00; H04N5/14; H04N5/147; H04N5/20; G09G2340/00; G09G2340/16; G09G5/00; G09G5/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
68 words
An image processing method, comprising: computing a normalized luminance histogram of each frame; computing scene-change-detecting reference values corresponding to correlations between two normalized luminance histograms of first and second frames computed in the computing of a normalized luminance histogram of each frame; and determining whether a change in scenes between images of the first and second frames has occurred or not, in accordance with the scene-change-detecting reference values.
Claim 2
Dependent Claim
68 words
An image processing method, comprising: computing a normalized luminance histogram of each frame; computing scene-change-detecting reference values corresponding to correlations between two normalized luminance histograms of first and second frames computed in the computing of a normalized luminance histogram of each frame; and determining whether a change in scenes between images of the first and second frames has occurred or not, in accordance with the scene-change-detecting reference values.
Claim 3
Dependent Claim
22 words
The image processing method according to claim 1 , the scene-change-detecting reference values including at least first and second scene-change-detecting reference values.
Claim 4
Dependent Claim
106 words
The image processing method according to claim 2 , in order to compute the first scene-change-detecting reference value, the computing of scene-change-detecting reference values including: computing the product of two distribution frequencies at each corresponding luminance level of the two normalized luminance histograms of the first and second frames; computing the square value of the distribution frequency at the corresponding luminance level of the normalized luminance histogram of the first frame; computing an absolute difference in the product and the square value; and computing the sum total of the absolute differences in a range of the luminance levels from the minimum luminance to the maximum luminance.
Claim 5
Dependent Claim
106 words
The image processing method according to claim 2 , in order to compute the second scene-change-detecting reference value, the computing of scene-change-detecting reference values including: computing the product of two distribution frequencies at each corresponding luminance level of the two normalized luminance histograms of the first and second frames; computing the square value of the distribution frequency at the corresponding luminance level of the normalized luminance histogram of the second frame; computing an absolute difference in the product and the square value; and computing the sum total of the absolute differences in a range of the luminance levels from the minimum luminance to the maximum luminance.
Claim 6
Dependent Claim
58 words
The image processing method according to claim 2 , the scene-change determining including: comparing at least one of the first and second scene-change-detecting reference values with a predetermined threshold; and determining that a change in the scenes has occurred when said at least one of the scene-change-detecting reference values is equal to or greater than the predetermined threshold.
Claim 7
Dependent Claim
47 words
The image processing method according to claim 5 , the comparing and determining including determining that a change in the scenes has occurred when both the first and second scene-change-detecting reference values are equal to or greater than another threshold which is smaller than the predetermined threshold.
Claim 8
Dependent Claim
43 words
The image processing method according to claim 5 , the comparing and determining including determining that a change in the scenes has occurred when the sum of the first and second scene-change-detecting reference values is equal to or greater than a predetermined value.
Claim 9
Dependent Claim
91 words
An image processing apparatus, comprising: a normalized-luminance-histogram computing unit to compute a normalized luminance histogram of each frame; a normalized-luminance-histogram storage unit to store the normalized luminance histogram of the frame; a scene-change-detecting reference-value computing unit to compute scene-change-detecting reference values corresponding to correlations between two normalized luminance histograms of first and second frames stored in the normalized-luminance-histogram storage units; and a scene-change determining unit to determine that a change in scenes between images of the first and second frames has occurred or not, in accordance with the scene-change-detecting reference values.
Claim 10
Dependent Claim
91 words
An image processing apparatus, comprising: a normalized-luminance-histogram computing unit to compute a normalized luminance histogram of each frame; a normalized-luminance-histogram storage unit to store the normalized luminance histogram of the frame; a scene-change-detecting reference-value computing unit to compute scene-change-detecting reference values corresponding to correlations between two normalized luminance histograms of first and second frames stored in the normalized-luminance-histogram storage units; and a scene-change determining unit to determine that a change in scenes between images of the first and second frames has occurred or not, in accordance with the scene-change-detecting reference values.
Claim 11
Dependent Claim
60 words
A projector, comprising: a light source to feed illumination light; a space modulation element to modulate the light from the light source in accordance with an image signal; the image processing apparatus according to claim 8 to process an image from the space modulation element; and a projection lens system to project the image processed by the image processing apparatus.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2010-07-16 | 2011-01-15 | 2011-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2014-07-16 | 2015-01-15 | 2015-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2018-07-16 | 2019-01-15 | 2019-07-17 | $7700.00 | Window Closed / Lapsed |