OpenCV Select Ink On Scanned Page

Question

Say we have a picture of a page with text on it. However, a threshold is not sufficient. On an example image, the page has a large shadow that covers half the image, such that at some points, there is paper that is darker than the lightest ink.

What's the best way to get a mask of the ink on the page? I'm thinking it's something like edge detection, although I wouldn't then know how to select the inner part of the ink.

I'm doing this in Python, so answers in that would be most helpful!

did u try filtering the image with the color of ink say (0,0,255) — v.coder, Sep 19 '16 at 15:21
Yep. In the question, I said that the darkest parts of the paper can appear darker than the lightest parts of the ink, so this is no-go. — Jacob Parker, Sep 19 '16 at 15:52

score 0 · Answer 1 · answered Sep 19 '16 at 16:30

0

There are two things you can try:

Convert the image to HSV and check the hue component
Use algorithms to remove shadow from the image and then process it. An example of such methods can be found in this paper

answered Sep 19 '16 at 16:30

v.coder

1,822
2
15
24

OpenCV Select Ink On Scanned Page

1 Answers1