Study On High-fidelity Color Image Acquisition Method Based On Multi-channel Imaging System

The high-fidelity color image acquisition of the digital imaging system means that the color of the scene can be accurately replicated.However,due to the hardware limitations of the traditional digital imaging system,the image may be distorted in color and it cannot clearly distinguish colors like the human eyes.Multi-channel digital imaging system is an efficient method to solve this problem.Metamer mismatching volume can effectively evaluate the accuracy of the color obtained by digital imaging systems.This study first investigated the relationship between theoretical metamer mismatching volume,practical metamer mismatching volume and the number of channels in the digital imaging system.The spectral sensitivity functions of multi-channel imaging system are designed based on Gaussian function.When the observer metamer mismatching and the illuminant & observer metamer mismatching happens,optimal spectral reflectance was generated and more than 47 million previously collected practical spectral reflectance were used to derive the metameric color pairs.Both the metamer mismatching volume and metamer mismatching index are used to analyze their relationship to the number of channels.The results show that both the theoretical and practical metamer mismatching volumes are significantly reduced when the number of channels increases from three to five,but only slightly reduced by further increasing from five to seven.The results also show that the practical metamer mismatching volumes and index are much smaller than theoretical.Based on the relationship between the metamer mismatching volumes and the number of channels in the digital imaging system,a multi-channel digital imaging system was constructed using a monochrome industrial cameras and different filters.The effects of the number of channels on the color high fidelity acquisition in the actual multi-channel image acquisition system are analyzed based on two color correction models,respectively.The results show that the color accuracy is significantly improved when the number of channels in the digital imaging system increases from three to five,but the improvement is less when the number increasing from five to six,which is consistent with the results based on metamer mismatching.Therefore,the relationship between the metamer mismatching volume based on the simulation and the number of channels,and the relationship between the color acquisition accuracy by the actual multi-channel digital imaging system and the number of channels,all indicate that five-channel digital imaging system can reduce metamer mismatching degree and obtain high-fidelity color images of objects.