compare_image_entropy.py 文件源码

def compare_entropy(name_img1,name_img2,method="rmq"):
     '''Compare two images by the Kullback-Leibler divergence

     Parameters
     ----------
     name_img1 : string
       filename of image 1 (png format)

     name_img2 : string
       filename of image 2 (png format)

     Returns
     -------
     S : float
        Kullback-Leibler divergence S = sum(pk * log(pk / qk), axis=0)

     Note
     ----
     See http://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.entropy.html
     '''
     img1 = mpimg.imread(name_img1)
     img2 = mpimg.imread(name_img2)
     fimg1 = img1.flatten()
     fimg2 = img2.flatten()
     if method == "KL-div":
          eps = 0.0001
          S = stats.entropy(fimg2+eps,fimg1+eps)
          S = numpy.log10(S)
     elif method == "rmq":
          fdiff=fimg1-fimg2
          fdiff_sqr = fdiff**4
          S = (fdiff_sqr.sum())**(old_div(1.,4))

     return S,fimg1, fimg2