HIGH ACCURACY COLOR CORRECTION PROCESSING METHOD AND HIGH ACCURACY COLOR CORRECTION PROCESSOR

To provide a high accuracy color correction processing method and a high accuracy color correction processor, which select and determine a color correction model having a suitable parameter freedom degree with consideration of noise caused by an imaging of a camera or a video compression, and carry...

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Bibliographic Details
Main Author MATSUNAGA TSUTOMU
Format Patent
LanguageEnglish
Japanese
Published 23.05.2019
Subjects
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRICITY
PICTORIAL COMMUNICATION, e.g. TELEVISION
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Summary:To provide a high accuracy color correction processing method and a high accuracy color correction processor, which select and determine a color correction model having a suitable parameter freedom degree with consideration of noise caused by an imaging of a camera or a video compression, and carry out a color matching processing with consideration of a white balance by using the color correction model.SOLUTION: A three-dimensional geometry conversion in a three-dimensional RGB color space to RGB data extracted from an image obtained by photographing a color chart is estimated by a statistically optimum method with consideration of an error covariance matrix. Also, in order to achieve a strict white balance correction, a correction after the event is performed so that a color chart white level becomes a designated ideal white level in accordance with an estimation result of the geometry conversion. On the basis of the estimation result of a geometry conversion model of a plurality of different freedom degrees, an optional model for balancing between complexity of the model and the degree of matching is determined by selecting the geometry model. A color correction processing by the three-dimensional conversion selected is calculated by a three-dimensional lookup table (3DLUT) interpolation.SELECTED DRAWING: Figure 1 【課題】カメラの撮像や映像圧縮に起因するノイズを考慮しつつ、適切なパラメータ自由度を有する色補正モデルを選択・決定して、当該色補正モデルを用いてホワイトバランスを考慮したカラーマッチング処理を遂行する高精度色補正処理方法及び高精度色補正処理装置を提案することを目的とする。【解決手段】カラーチャートを撮影した画像から抽出したＲＧＢデータに対して、３次元ＲＧＢ色空間における３次元幾何学変換を、誤差の共分散行列を考慮した統計的に最適な方法により推定する。また、厳密なホワイトバランス補正を実現するために、幾何学変換の推定結果に対して、カラーチャート白レベルが指定した理想的な白レベルとなるように事後的な補正を行う。複数の異なる自由度の幾何学変換モデルの推定結果から、幾何学的モデル選択によりモデルの複雑さと当てはまりのよさをバランスする最適なモデルを決定する。そして、選択された３次元幾何学変換による色補正処理を３次元ルックアップテーブル（３ＤＬＵＴ）補間により計算する。【選択図】図１
Bibliography:Application Number: JP20170203365