COLOR TONE CHANGE DETECTION DEVICE, COLOR TONE CHANGE DETECTION METHOD AND PROGRAM

• Main Authors: YAMAJI HIRONAO, UMEMURA JUN
• Format: Patent
• Language: English; Japanese
• Published: 30.10.2014
• Subjects: COLORIMETRY; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; PHYSICS; RADIATION PYROMETRY; TESTING

PROBLEM TO BE SOLVED: To more accurately detect a color tone change which may be generated on a surface of a band-like body even in the case where an illumination color temperature of illumination light irradiating the surface of the band-like body is changed.SOLUTION: A color tone change detection device comprises: a color chart member formed from three or more color pallets which are disposed outside an end portion of a band-like body in a width direction and of which the color tones are different from each other; an imaging apparatus including a light source irradiating the color chart member and a surface of the band-like body with illumination light and a color camera for imaging the surface of the band-like body and the color chart member so as to position them within the same field of view and generating a color captured image; and an arithmetic processing unit including a correction matrix determination section for determining a correction matrix by utilizing an image in a portion where the color chart member is imaged, a color tone correction section for correcting a color tone in a portion where the surface of the band-like body is imaged while using the correction matrix, and a determination section for determining whether a color tone change occurs on the surface of the band-like body in accordance with a position in a color space of a color tone corresponding to the surface of the band-like body while utilizing the color captured image after the color tone correction. 【課題】帯状体表面に照射される照明光の照明色温度が変化する場合であっても帯状体表面に発生しうる色調変化をより正確に検出すること。【解決手段】本発明に係る色調変化検出装置は、帯状体の幅方向の端部の外側に配設され、互いに色調の異なる３個以上の色パレットから構成されるカラーチャート部材、カラーチャート部材及び帯状体表面に照明光を照射する光源、並びに、帯状体表面及びカラーチャート部材をこれらが同一視野内に位置するよう撮像しカラー撮像画像を生成するカラーカメラを有する撮像装置と、カラーチャート部材が撮像された部分の画像を利用して補正行列を決定する補正行列決定部、当該補正行列を用いて帯状体表面が撮像された部分の色調を補正する色調補正部、及び、色調補正後のカラー撮像画像を利用し帯状体表面に対応する色調の色空間での位置に応じて帯状体表面に色調変化が生じたかを判定する判定部を有する演算処理装置と、を備える。【選択図】図１