Python 使用numpy和cv2操作大型二值图像阵列

我的代码如下：

import cv2; import numpy as np

class MyClass:
    def __init__(self,imagefile):
        self.image = cv2.imread(imagefile)

        #image details
        self.h,self.w = self.image.shape[:2]
        #self.bPoints, self.wPoints = np.array([[0,0]]),np.array([[0,0]])
        self.bPoints, self.wPoints = [],[]

        #CAUTION! Points are of the form (y,x)
        # Point filtering
        for i in xrange(self.h):
            for j in xrange(self.w):
                if self.th2.item(i,j) == 0:
                    #self.bPoints = np.append([[i,j]], self.bPoints, axis=0)
                    self.bPoints.append((i,j))
                else:
                    self.wPoints.append((i,j))
                    #self.wPoints = np.append([[i,j]], self.wPoints, axis=0)

        #self.bPoints = self.bPoints[:len(self.bPoints) - 1]
        #self.wPoints = self.wPoints[:len(self.wPoints) - 1]
        self.bPoints, self.wPoints = np.array(self.bPoints), np.array(self.wPoints)

我想找到并区分黑点和白点。我已经评论了通过numpy显示可能（但非常慢）解决方案的行。你能给我推荐一个更好更快的解决方案吗？如果你这样做，我将不胜感激

---

谢谢

我假设

self.th2

是一个numpy数组。如果不是这样的话，这可能需要一些调整。基本上，它使用

np.where

函数来确定

0

或

255

的所有索引

import cv2; import numpy as np

class MyClass:
    def __init__(self,imagefile):
        self.image = cv2.imread(imagefile)

        #image details
        self.h,self.w = self.image.shape[:2]
        #self.bPoints, self.wPoints = np.array([[0,0]]),np.array([[0,0]])
        self.bPoints, self.wPoints = [],[]

        #CAUTION! Points are of the form (y,x)
        # use the np.where method instead of a double loop. 
        # make sure self.th2 is a numpy array
        indx = np.where(self.th2==0)
        for i,j in zip(indx[0], indx[1]):
            self.bPoints.append((i,j))

        indx = np.where(self.th2==255)
        for i,j in zip(indx[0], indx[1]):
            self.wPoints.append((i,j))

        # Point filtering
        #for i in xrange(self.h):
        #    for j in xrange(self.w):
        #        if self.th2.item(i,j) == 0:
        #            #self.bPoints = np.append([[i,j]], self.bPoints, axis=0)
        #            self.bPoints.append((i,j))
        #        else:
        #            self.wPoints.append((i,j))
        #            #self.wPoints = np.append([[i,j]], self.wPoints, axis=0)

        #self.bPoints = self.bPoints[:len(self.bPoints) - 1]
        #self.wPoints = self.wPoints[:len(self.wPoints) - 1]
        self.bPoints, self.wPoints = np.array(self.bPoints), np.array(self.wPoints)

---

也许它需要添加一个句子来说明您试图实现的目标。正如我上面提到的，我想将二值图像的黑点附加到

self.b点

，将白点附加到

self.wPoints

数组，其形状为

（2,2）

谢谢！快多了！但是请注意，白色的值是255，而不是1。我想的是

np.where（）

，但我不知道如何操作它！这无疑是制作索引的好方法！