A method for radiometric calibration of a color camera by using a multispectral image

Abstract

The invention discloses a method for radiometric calibration of a color camera by using a multi-spectral image, namely solving an inverse camera response function and a spectral sensitivity function of the color camera. The method comprises the following steps: The intrinsic linearity between pixels in a multi-spectral image is searched, and the inverse camera response function is estimated by restoring the intrinsic linearity from a color (RGB) image. The spectral sensitivity function and the inverse camera response function coupled in the RGB image are solved by alternating iteration of theexisting data. The results show that the intrinsic linearity is not only the intrinsic linearity between pixels but also the intrinsic linearity between pixels. The invention uses the scene spectrum information provided by the multi-spectrum image, reduces the error caused by the inaccurate use information of the traditional method, improves the radiometric calibration accuracy of the camera, andsimultaneously obtains two calibration information of the inverse camera response function and the spectrum sensitivity function.

Description

technical field [0001] The invention relates to the radiation calibration of the color camera, and can accurately obtain the inverse camera response function and spectral sensitivity function of the color camera under the condition of known scene multispectral image information. Background technique [0002] Obtaining accurate radiometric calibration information of color cameras is helpful for the implementation of many image processing algorithms, such as multispectral imaging, illumination estimation, color correction, etc. Since camera manufacturers usually do not provide this information, the camera inverse response function and spectral sensitivity function need to be estimated accurately. [0003] The camera response function converts the irradiance received by the camera sensor into the brightness of the image. In order to enhance the visual effect of the captured image, the camera response function is nonlinear in most cameras, and the role of the inverse camera res...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problems of the existing color camera radiometric calibration algorithm with low accuracy and limited application scenarios, and pro

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