Reputation:
I have a problem with a binarization method.
I have images with text, which I want to binarize.
I want the text ends up being white, but there are images with the text darker than the background and there are images with text less dark than the background.
I want to binarize images like these, but I want the text in white color in the binarized images.
By the way, I am binarizing images with this code. This code is good for images with text darker than the background but it isn't good for text less darker than the background. I think I need a method to know if the text is more or less dark than the background for to invert or no invert the binarization.
umb = graythresh(originalImage);
binaryImage =(~im2bw(originalImage,umb));
How can I do it?
Thanks a lot for the help
Upvotes: 0
Views: 215
Reputation: 5822
there are 2 possible solutions which I had in mind:
solution1:
generate a grayscale image using rgb2gray function.
generate a histogram from the grayscale image, and ignore the transparent pixels. you can use imhist function.
check what is the histogram maximal value. if the value is high - the background is probably light and the text should be darker than the background. in this case - take the negative image (for example, by using imcomplement), and then binarize it. otherwise - you can binarize it as is.
solution 2:
the solution asserts that the image is simple enough, i.e. doesn't have a lot of connected components other than the letters.
good luck!
Upvotes: 1