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EP0663779A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

A white-balance adjusting apparatus and a method thereof for a video camera

Assignee: LG Electronics Inc
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Filing: 1994-12-21
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Granted: —
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Expires: 2014-12-21
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Abstract

Abstract An improved white-balance adjusting apparatus and a method thereof for a video camera capable of automatically varying a white-balance trace region in accordance with a change of color temperatures of a light source and of performing an automatic white-balance adjusting operation, which includes a dividing circuit for integrating a first primary color signal for a predetermined time and for computing an integration value ratio of a second primary color signal in response to the integration value ratio of the first primary color signal; a color temperature detection circuit for detecting a color temperature change of a light source from the integration value ratio; and a gain computation circuit, when an integration value ratio is within a range of at least one white-balance trace region, for selecting a white-balance trace region in accordance with a detected color temperature change and for computing a gain of a primary color in accordance with the integration value ratio in a range of a selected white-balance trace region

Inventors

  • 👤 Sang Woon Suh

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 17:05
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/80; H04N23/84; H04N23/88; H04N23/60

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 127 words
A white-balance adjusting apparatus for a video camera, comprising: divider means for integrating a first primary color signal for a predetermined time and for computing an integration value ratio of a second primary color signal in response to the integration value ratio of the first primary color signal; color temperature detection means for detecting a color temperature change of a light source from the integration value ratio; and gain computation means, when an integration value ratio is within a range of at least one white-balance trace region, for selecting a white-balance trace region in accordance with a detected color temperature change and for computing a gain of a primary color in accordance with a the integration value ratio in a range of a selected white-balance trace region
Claim 2
Dependent Claim 57 words
The apparatus of claim 1, wherein said at least one white-balance trace region includes a first region defined when a color temperature of a light source moves from a high region to a low region and a second region defined when a color temperature of a light source moves from a low region to a high region.
Claim 3
Dependent Claim 49 words
The apparatus of claim 1, wherein said color temperature detection means includes a plurality of delay means for delaying a plurality of integration value ratios for a predetermined time and a plurality of comparing means for comparing a delayed previous integration value ratio with a current integration value ratio.
Claim 4
Dependent Claim 15 words
The apparatus of claim 3, wherein said predetermined time is a time for one field.
Claim 5
Dependent Claim 128 words
A white-balance adjusting method for a video camera, comprising the steps of: a fist step for computing a second integration value ratio of a second primary color signal in response to a first integration value ratio of a first primary color signal and for detecting whether or not the computed integration value ratio in within a predetermined range of a plurality of white-balance trace regions; a second step, when the computed integration value ratio is within the range of the white-balance trace regions, for selecting a corresponding white-balance trace region by detecting a color temperature change from the computed integration value; and a third step for adjusting a gain of a primary color signal using an integration value ratio which is computed in the selected white-balance trace region.
Claim 6
Dependent Claim 37 words
The method of claim 5, wherein said color temperature change detection step is performed by comparing an integration value ratio of a previous field which is outputted after a predetermined time with a current integration value ratio.
Claim 7
Dependent Claim 13 words
The method of claim 6, wherein said predetermined time is during a field.
Claim 8
Dependent Claim 55 words
The method of claim 6, wherein at leans one trace region includes a first region defined when a color temperature of a light source moves from a low region to a high region and a second region defined when a color temperature of a light source moves from a high region to a low region.

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