US8135235B2
Active / In Force
US
⏱️ 2.4 years remaining
Pre-processing method and apparatus for wide dynamic range image processing
Assignee: Industry Academy Collaboration Foundation of Korea University
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Filing: 2009-03-18
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Granted: 2012-03-13
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Expires: 2029-03-18
Abstract
Abstract Provided are method and apparatus of pre-processing in WDR (wide dynamic range) image processing, the method of pre-processing of WDR image processing including: (a) receiving luminance and chrominance signals having different exposure times, and analyzing the correlation between a luminance signal having a first exposure time and a luminance signal having a second exposure time that is longer than the first exposure time; (b) based on the result of the analysis, dividing each of the luminance signal having the first exposure time and the luminance signal having the second exposure signal, into at least one of a bright region, a transition region, and a dark region; and (c) normalizing the regions of the luminance signal having the first exposure time to respectively correspond to the regions of the luminance signal having the second exposure times.
Inventors
- 👤 Bong-hyup Kang
- 👤 Chang-won Jeon
- 👤 Han-seok Ko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:02
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/20; H04N23/00; H04N23/70; H04N23/73; H04N23/741; H04N23/76; H04N5/44; H04N5/57
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
128 words
A method of pre-processing in wide dynamic range (WDR) image processing, the method comprising: (a) receiving luminance and chrominance signals having different exposure times, analyzing, utilizing a processor, the correlation between a luminance signal having a first exposure time and a luminance signal having a second exposure time that is longer than the first exposure time; (b) based on the result of the analysis, dividing each of the luminance signal having the first exposure time and the luminance signal having the second exposure time into at least one of a bright region, a transition region, and a dark region; and (c) normalizing the regions of the luminance signal having the first exposure time to respectively correspond to the regions of the luminance signal having the second exposure time.
Claim 2
Independent Claim
128 words
A method of pre-processing in wide dynamic range (WDR) image processing, the method comprising: (a) receiving luminance and chrominance signals having different exposure times, analyzing, utilizing a processor, the correlation between a luminance signal having a first exposure time and a luminance signal having a second exposure time that is longer than the first exposure time; (b) based on the result of the analysis, dividing each of the luminance signal having the first exposure time and the luminance signal having the second exposure time into at least one of a bright region, a transition region, and a dark region; and (c) normalizing the regions of the luminance signal having the first exposure time to respectively correspond to the regions of the luminance signal having the second exposure time.
Claim 3
Dependent Claim
43 words
The method of claim 1 , wherein the analysis of the correlation is conducted using a 2D histogram expressing luminance components in the same pixel of the luminance signal having the first exposure time and the luminance signal having the second exposure time.
Claim 4
Dependent Claim
94 words
The method of claim 1 , wherein (b) comprises: (b1) determining a boundary between the bright region and the transition region using a distance between a portion of the luminance signal having the second exposure time in which the brightness of the luminance signal is abruptly changed, and a maximum luminance component of the luminance signal having the second exposure time; and (b2) determining a boundary between the transition region and the dark region based on the boundary between the luminance region and the transition region, depending on the received luminance and chrominance signals.
Claim 5
Dependent Claim
29 words
The method of claim 3 , wherein the boundary between the bright region and the transition region is determined based on a point where the distance is the smallest.
Claim 6
Dependent Claim
48 words
The method of claim 4 , wherein the boundary between the transition region and the dark region is fixed to a multiple of a fractional number between 0 and 1 of the point where the distance is the smallest depending on the condition of the obtained image signals.
Claim 7
Dependent Claim
67 words
The method of claim 1 , wherein (c) comprises: (c1) calculating a gain and an offset with respect to each of the regions; and (c2) calculating and normalizing the regions of the luminance signal having the first exposure time so as to respectively correspond to the maximums of the regions of the luminance signal having the second exposure time using the calculated gain and the calculated offset.
Claim 8
Independent Claim
141 words
A method of wide dynamic range (WDR) image processing, the method comprising: (a) receiving luminance and chrominance signals having different exposure times and normalizing a luminance signal having a first exposure time so as to correspond to a luminance signal having a second exposure time that is longer than the first exposure time; (b) adding up, utilizing a processor, the luminance signal having the second exposure time and the normalized luminance signal having the first exposure time using a first weight; (c) adding up a chrominance signal having the first exposure time and a chrominance signal having the second exposure time using a second weight to which the result of the adding in (b) is reflected; and (d) converting the added luminance signal and the added chrominance signal into a RGB signal to be output as a WDR resultant image signal.
Claim 9
Independent Claim
141 words
A method of wide dynamic range (WDR) image processing, the method comprising: (a) receiving luminance and chrominance signals having different exposure times and normalizing a luminance signal having a first exposure time so as to correspond to a luminance signal having a second exposure time that is longer than the first exposure time; (b) adding up, utilizing a processor, the luminance signal having the second exposure time and the normalized luminance signal having the first exposure time using a first weight; (c) adding up a chrominance signal having the first exposure time and a chrominance signal having the second exposure time using a second weight to which the result of the adding in (b) is reflected; and (d) converting the added luminance signal and the added chrominance signal into a RGB signal to be output as a WDR resultant image signal.
Claim 10
Dependent Claim
105 words
The method of claim 7 , wherein (a) comprises: (a1) analyzing the correlation between the luminance signal having the first exposure time and the luminance signal having the second exposure time, and dividing each of the luminance signal having the first exposure time and the luminance signal having the second exposure signal into at least one of a bright region, a transition region, and a dark region, based on the result of the analysis; and (a2) normalizing the regions of the luminance signal having the first exposure time so as to respectively correspond to the regions of the luminance signal having the second exposure time.
Claim 11
Dependent Claim
57 words
The method of claim 8 , wherein (b) comprises: (b1) calculating a first weight using the luminance signal having the second exposure time and the result of division of the regions; and (b2) adding up the luminance signal having the second exposure time and the luminance signal having the first exposure time using the calculated first weight.
Claim 12
Dependent Claim
21 words
The method of claim 9 , wherein the first weight is calculated by using the result of division of the regions.
Claim 13
Dependent Claim
22 words
The method of claim 9 , wherein (b) further comprises performing a contrast ratio enhancing process on the result of the addition.
Claim 14
Dependent Claim
139 words
A non-transitory computer readable storage medium having embodied thereon a computer program for executing a method of pre-processing in wide dynamic range (WDR) image processing, the method comprising: (a) receiving luminance and chrominance signals having different exposure times, analyzing the correlation between a luminance signal having a first exposure time and a luminance signal having a second exposure time that is longer than the first exposure time; (b) based on the result of the analysis, dividing each of the luminance signal having the first exposure time and the luminance signal having the second exposure time into at least one of a bright region, a transition region, and a dark region; and (c) normalizing the regions of the luminance signal having the first exposure time to respectively correspond to the regions of the luminance signal having the second exposure time.
Claim 15
Dependent Claim
139 words
A non-transitory computer readable storage medium having embodied thereon a computer program for executing a method of pre-processing in wide dynamic range (WDR) image processing, the method comprising: (a) receiving luminance and chrominance signals having different exposure times, analyzing the correlation between a luminance signal having a first exposure time and a luminance signal having a second exposure time that is longer than the first exposure time; (b) based on the result of the analysis, dividing each of the luminance signal having the first exposure time and the luminance signal having the second exposure time into at least one of a bright region, a transition region, and a dark region; and (c) normalizing the regions of the luminance signal having the first exposure time to respectively correspond to the regions of the luminance signal having the second exposure time.
Claim 16
Dependent Claim
138 words
A pre-processing apparatus in a wide dynamic range (WDR) image processing, comprising: a region determining unit for receiving luminance and chrominance signals having different exposure times and among the different exposure times, analyzing the correlation between a luminance signal having a first exposure time and a luminance signal having a second exposure time that is longer than the first exposure time, and dividing each of the luminance signal having the first exposure time and the luminance signal having the second exposure signal into at least one of a bright region, a transition region, and a dark region, based on the result of the analysis; and a normalizing unit for normalizing the regions of the luminance signal having the first exposure time so as to respectively correspond to the regions of the luminance signal having the second exposure time.
Claim 17
Dependent Claim
138 words
A pre-processing apparatus in a wide dynamic range (WDR) image processing, comprising: a region determining unit for receiving luminance and chrominance signals having different exposure times and among the different exposure times, analyzing the correlation between a luminance signal having a first exposure time and a luminance signal having a second exposure time that is longer than the first exposure time, and dividing each of the luminance signal having the first exposure time and the luminance signal having the second exposure signal into at least one of a bright region, a transition region, and a dark region, based on the result of the analysis; and a normalizing unit for normalizing the regions of the luminance signal having the first exposure time so as to respectively correspond to the regions of the luminance signal having the second exposure time.
Claim 18
Dependent Claim
43 words
The apparatus of claim 13 , wherein the analysis of the correlation is conducted using a 2D histogram expressing luminance components in the same pixel of the luminance signal having the first exposure time and the luminance signal having the second exposure time.
Claim 19
Dependent Claim
176 words
A wide dynamic range (WDR) image processing apparatus, comprising: a luminance/chrominance converting unit for converting image signals obtained at different exposure times into luminance and chrominance signals; a pre-processing unit for normalizing a luminance signal having a first exposure time among the different exposure times to correspond to a luminance signal having a second exposure time that is longer than the first exposure time; a luminance fusing unit for adding up the luminance signal having the second exposure time and the normalized luminance signal having the first exposure time using a first weight; a chrominance fusing unit for adding up a chrominance signal having the first exposure time and a chrominance signal having the second exposure time using a second weight to which the result of the addition of the luminance fusing unit is reflected; and an RGB converting unit for converting the fused luminance signal output from the luminance fusing unit and the fused chrominance signal output from the chrominance fusing unit into an RGB signal to be output as a WDR resultant image signal.
Claim 20
Dependent Claim
176 words
A wide dynamic range (WDR) image processing apparatus, comprising: a luminance/chrominance converting unit for converting image signals obtained at different exposure times into luminance and chrominance signals; a pre-processing unit for normalizing a luminance signal having a first exposure time among the different exposure times to correspond to a luminance signal having a second exposure time that is longer than the first exposure time; a luminance fusing unit for adding up the luminance signal having the second exposure time and the normalized luminance signal having the first exposure time using a first weight; a chrominance fusing unit for adding up a chrominance signal having the first exposure time and a chrominance signal having the second exposure time using a second weight to which the result of the addition of the luminance fusing unit is reflected; and an RGB converting unit for converting the fused luminance signal output from the luminance fusing unit and the fused chrominance signal output from the chrominance fusing unit into an RGB signal to be output as a WDR resultant image signal.
Claim 21
Dependent Claim
117 words
The WDR image processing apparatus of claim 15 , wherein the pre-processing unit comprises: a region determining unit for analyzing the correlation between the luminance signal having the first exposure time and the luminance signal having the second exposure time, and dividing each of the luminance signal having the first exposure time and the luminance signal having the second exposure time into at least one of a bright region, a transition region, and a dark region, based on the result of the analysis; and a normalizing unit for normalizing the regions of the luminance signal having the first exposure time so as to respectively correspond to the regions of the luminance signal having the second exposure time.
Claim 22
Dependent Claim
72 words
The WDR image processing unit of claim 15 , wherein the luminance fusing unit comprises: a weight calculation unit for calculating a first weight using the luminance signal having the second exposure time and the result of division of the regions; and a weight adding unit for adding up the luminance signal having the second exposure time and the normalized luminance signal having the first exposure time using the calculated first weight.
Claim 23
Dependent Claim
37 words
The WDR image processing apparatus of claim 17 , wherein the luminance fusing unit further comprises a post-processing unit for performing a contrast ratio enhancing process on the result of the addition of the weight adding unit.
Claim 24
Dependent Claim
79 words
The WDR image processing apparatus of claim 15 , wherein the chrominance fusing unit comprises: a weight calculation unit for calculating the second weight using the luminance signal having the first exposure time, the luminance signal having the second exposure time, and the result of addition of the luminance fusing unit; and a weight adding unit adding the chrominance signal having the first exposure time and the chrominance signal having the second exposure time using the calculated second weight.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 2015-03-13 | 2015-09-12 | 2016-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2019-03-13 | 2019-09-12 | 2020-03-13 | $3760.00 | Window Closed / Lapsed |
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