Color Prediction Model Of Print Based On Murray-Davies Equation-Microscopic Color Prediction Of Fm Halftoning Image

How the image quality can be analyzed, evaluated and predicted effectively and accurately is an important subject in printing industry. Image quality is related to the color (or tone) reproduction which is the macroscopic characteristic and the sharpness and granularity of dots which are the microscopic characteristics. The spatial distribution of FM halftoning image dots has a certain degree of randomness, which are generated by a random function and distributed according to the optical density. The tone level of the original printing image is reproduced by changing the spatial distribution frequency of dots with the same size and thus reflects the subtle changes better and make the printing image clearer. However, due to the sizes of FM halftoning dots are much smaller than the size of AM's, the dot gain degree of FM is serious, which affects the reproduction of images and hinders the application of FM halftoning in printing wildly. In this paper, based on analyzing the microstructure of FM halftoning image and light scattering of paper and ink spreading, combining the factors that affect dot gain, a color prediction model of FM halftone printed image based on Murray-Davies equation is studied. Firstly, the microscopic structure and characteristics of FM halftone image is analyzed. Taking into account the influence of light scattering, the relationship of reflection and transmission partially for dots and vacancy between dots is analyzed using the probability theory of light scattering and the microstructure color predictions for Monochrome and two inks overlap are established. Then, the physical dot gain caused by ink spreading is analyzed quantitatively and is introduced to the color prediction model to make the color prediction model more accurately. Based on the analysis above,a new prediction model based on expanded Murray-Davies equation for FM halftone printed image on microscopic level is developed and the accuracy of the new model is verified by numerical simulation with MATLAB software. It's verified that the new model have a more accurate, so that this new model can be used to control dot gain effectively and predict spectral reflectance of FM halftoning image more accurately.