在图像中用白色替换黑色，用白色替换黑色

Question

I have black and white images (png) as follow : l want to replace the black background font color into white and the written character in white to black. How to identify color and replace it ?

for that l have thousand of images. It s not possible to manually identify in which image the character is in black and the background is in white and vice versa. all what l need is for every image l check if the character is written in black if not change the character color to black and the background to white.

here is a link to my sample of data : https://drive.google.com/open?id=0B-QJnh0Uw96lbFVHbVBPclhycFk

Answer 1

如果白色内容的值为255（如果它是二进制掩码1），则从255中减去您的图像。在python中，如果您的图像为img ：

cv2.subtract(255, img) 

Answer 2

对于您提供的示例，如果图像尺寸>〜26像素宽，请反转。