图像评价的几个标准，包括峰值信噪比，均方误差，平均绝对误差，图像保真度，信噪比的MATLAB代码，采用基本编程方法，适合初学者加深图像客观评价标准的理解。-Image evaluation of several criteria, including PSNR, MSE, mean absolute error, image fidelity, signal to noise ratio of the MATLAB code, using the basic programming for be