A Generalized Von Kries Transform

With the development of color science and the wide application of image reconstruction technology in all kinds of multimedia equipment,the demand for the quality of color rendered by a color media device is getting higher and higher.In order to achieve cross media color reproduction and large scale applications in digital video and other fields,color matching under different observation environment has become the most concern of people.With the emerging of the Von kries hypothesis and the modelling of chromatic adaptation,the color matching is no longer a difficult problem.In the process of the realization of cross media color reproduction,color appearance model plays a vital role,and the chromatic adaptation model is also the key to achieve the color appearance model.Further more,chromatic adaptation model can also be used in color reproduction,image processing and other industrial fields.Therefore,the establishment of chromatic adaptation model has become an important topic for scientists.More than 100 years of development,chromatic adaptation model has become more and more mature.At present,the most prominent is the CAT16 chromatic adaptation model proposed by Professor Li Changjun in 2016.However,after many years of development,although the model performance is getting better and better,the present model of chromatic adaptation is no longer able to satisfy the symmetry law and transitivity law proposed in the original Von kries hypothesis.In order to satisfy the mutual transformation between the corresponding colors,two links need to be added to the existing model,including forward model computation and inverse model operation,which makes the computational model more complex,and the calculation results also have greater deviations.Therefore,the study of improved algorithm for chromatic adaptation model is an urgent problem to be solved.In this paper,a two step CAT16 color adaptation model is proposed first,which is an improved algorithm based on the original CAT16 model.The algorithm used a ideal light source as the intermediate variable to split the one-step CAT model into two steps,which finally makes the model satisfies the symmetry law and transitivity law.According to the results of CIELAB color difference assessment,it is further proved that the two step CAT model is more prominent in the color prediction.As the ideal light source does not exist in the actual phenomenon,people still dispute about whether it is reasonable to introduce an ideal light source.To solve this problem,basing on the basic idea of Von kries,a new optimization algorithm is proposed in this paper,which is called generalized Von kries chromatic adaptation model.The newmodel not only satisfies the symmetry law and transitivity law,but also performs more better on the predicting of experimental data It can be said that the generalized Von kries model is the best chromatic adaptation model at present,further more,the research results in this paper will provide a new idea for the development of the chromatic adaptation model in the future.