一幅大小为256×256的256级灰度图像（每像素8bit）
如果图像的各个像素之间是统计独立的，求该图像的信息熵
-离散无记忆信源
如果图像的各个像素之间不是统计独立的，求该图像的信息熵
-图像像素的概率分布模型(A 256 gray scale image (8bit per pixel) with a size of 256 x 256
If each pixel of the image is statistically independent, the information entropy of the image is calculated
Discrete memoryless source
If each pixel of the image is not statistically independent, the information entropy of the image is calculated
Probability distribution model of image pixels)