SPECTRAL SENSITIVITY CORRECTION FILTER, IMAGING APPARATUS EMPLOYING THE SAME, AND SPECTRAL SENSITIVITY ADJUSTMENT METHOD

• Main Authors: SOENO TAKUJI, YAMASHITA TAKAYUKI, FUNATSU RYOHEI, HAYASHIDA TETSUYA, NAKAMURA TOMOHIRO
• Format: Patent
• Language: English; Japanese
• Published: 28.05.2015
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION; SEMICONDUCTOR DEVICES

PROBLEM TO BE SOLVED: To provide an imaging apparatus employing a spectral sensitivity correction filter that reduces a color difference E when approximating captured video information to a desired color reproduction property, and a spectral sensitivity adjustment method.SOLUTION: Spectral sensitivity close to an ideal imaging property is produced by a spectral sensitivity correction filter 11 so as to provide an ideal color signal property in a predetermined format (e.g., a video format of ITU-RBT/2020 or the like). In addition to a color filter 12 or an image sensor 13, an imaging system is set to which a transmission property, a gain and a linear matrix of the spectral sensitivity correction filter 11 are added. A spectral sensitivity propertyS'(λ) is defined by transmission property C(λ) of spectral sensitivity correction filter 11×transmission propertyT(λ) of color filter 12×spectral sensitivity property S(λ) of image sensor 13×gainG×linear matrix L. While using a least square method, the transmission property C(λ), the gainG and the linear matrix M of the spectral correction filter 11 are calculated which are capable of optimizing the spectral sensitivity propertyS'(λ). 【課題】撮像した映像情報を望む色再現特性に近似する際、色差 Ｅを低減し、分光感度補正フィルタを用いた撮像装置及び分光感度調整方法を提供する。【解決手段】分光感度補正フィルタ１１で、所定フォーマット（例えば、ITU-RBT/2020等の映像フォーマット）による理想的な色信号特性となるよう、理想撮像特性に近い分光感度を生成する。カラーフィルタ１２やイメージセンサ１３の他、分光感度補正フィルタ１１の透過特性、ゲイン、リニアマトリックスを加えた撮像系を設定し、分光感度特性→Ｓ'(λ)を、分光補正フィルタ１１の透過特性Ｃ(λ)?カラーフィルタ１２の透過特性→Ｔ(λ)?イメージセンサ１３の分光感度特性Ｓ(λ)?ゲイン→Ｇ?リニアマトリックスＬ、により定義し、最小二乗法を用い、この分光感度特性→Ｓ'(λ)を最適にし得る、分光補正フィルタ１１の透過特性Ｃ(λ)、ゲイン→Ｇ、リニアマトリックスＭを算出する。【選択図】図１