python-2.7 - 使用 k 均值进行图像分割

Question

我正在尝试使用 k-means 算法来执行图像分割任务。问题是我的程序没有分割图像。您能帮我找出代码中的错误吗？

事实上，我已将簇数固定为 32。我使用了以下数据结构:

• 3 个数组 bleu,vert,rouge 用于存储每个像素的 RGB 值

• 3 个数组 cluster_bleu、cluster_rouge、cluster_vert 用于存储每个簇的 RGB 值

• groupe[i,0]=k 将每个像素 i 映射到簇 k

  import cv2
  
  import numpy
  
  import random
  def main():
      MAX_LARGEUR = 400
      MAX_HAUTEUR = 400
  
      K = 32 #Le fameux parametre K de l'algorithme
      imagecolor = cv2.imread('perr.jpg')
  
  
      if imagecolor.shape[0] > MAX_LARGEUR or imagecolor.shape[1] > MAX_HAUTEUR:
          factor1 = float(MAX_LARGEUR) / imagecolor.shape[0]
          factor2 = float(MAX_HAUTEUR) / imagecolor.shape[1]
          factor = min(factor1, factor2)
          imagecolor = cv2.resize(imagecolor, None, fx=factor, fy=factor, interpolation=cv2.INTER_AREA)
  
  
      nb_pixels = imagecolor.shape[0] * imagecolor.shape[1]
  
      bleu = imagecolor[:, :, 0].reshape(nb_pixels, 1)
      vert = imagecolor[:, :, 1].reshape(nb_pixels, 1)
      rouge = imagecolor[:, :, 2].reshape(nb_pixels, 1)
  
  
      cluster_bleu = numpy.zeros(K)
      cluster_vert = numpy.zeros(K)
      cluster_rouge = numpy.zeros(K)
  
      groupe = numpy.zeros((nb_pixels, 1)) 
  
      for i in range(0,K):
          groupe[i,0]=i
  
      for i in range(K,nb_pixels):
          groupe[i,0]=random.randint(0, K-1)
  
  
      condition =False
  
  
  
  
      def etape1(indices,i):
      s=indices.size
      rouge_s=0
      vert_s=0
      bleu_s=0
      #calcul de barycentre des points
      if s==0:
          cluster_rouge[i]=0  
          cluster_vert[i]=0
          cluster_bleu[i]=0
  
  
      if s >=1:
          for j in range(0,s):
              rouge_s=rouge_s+rouge[indices[j]]
              vert_s=vert_s+vert[indices[j]]
              bleu_s=bleu_s+bleu[indices[j]]
  
          #mise  jour des clusters 
  
          cluster_rouge[i]=rouge_s/s  
          cluster_vert[i]=vert_s/s
          cluster_bleu[i]=bleu_s/s        
  
  
      iteration=0
      oldGroupe = numpy.copy(groupe)
      while(condition==False) :
  
  
      for i in range(0,K):
  
          indices=numpy.where(groupe==i)[0]
          etape1(indices,i)
  
  
  
      for i in range(0,nb_pixels):
          minimum=10000;
          dist=0;
          index=-1;
          for j in range(0,K):
               dist=(cluster_rouge[j]-rouge[i])**2+(cluster_vert[j]-vert[i])**2+(cluster_bleu[j]-bleu[i])**2;
               if(dist<=minimum):
                  minimum=dist;
                  index=j;
  
  
  
          groupe[i,0]=index;
  
  
  
      condition=numpy.all(groupe==oldGroupe)
  
      oldGroupe = numpy.copy(groupe)  
  
  
      groupe=numpy.reshape(groupe, (imagecolor.shape[0], imagecolor.shape[1]))
  
  
  
  
      for i in range(0, imagecolor.shape[0]):
          for j in range(0, imagecolor.shape[1]):
              imagecolor[i,j,0] = (cluster_bleu[groupe[i,j]])
              imagecolor[i,j,1] = (cluster_vert[groupe[i,j]])
              imagecolor[i,j,2] = (cluster_rouge[groupe[i,j]])
  
      cv2.namedWindow("sortie")
      cv2.imshow("sortie", imagecolor)
      key = cv2.waitKey(0)
  if __name__ == "__main__":
      main()
  

Answer 1

问题是赋值oldGroupe=groupe;，它不复制数组，而是创建具有不同名称的引用(oldGroupe)，该引用指向与组。因此，当您更改 groupe 时，您也会更改 oldGroupe，并且 condition 始终为 True。

您想要的是使用 oldGroupe = numpy.copy(groupe) 在 groupe 中创建数据副本。