Extracting Numbers from an Image using OpenCV

Question

I have Images like these from which I want to extract the Numbers.

I've been working with OpenCV and Template Matching in particular Interested me, but as the technique doesn't account for any image scaling and rotation, I'm out looking for techniques that may be able to take atleast scaling into account.

Please offer any suggestion or help. All operation are in Real Time.

P.S. Image quality cannot be improved, The camera's capability is as such.

Answer 1

Investigate SIFT: Scale Invariant Feature Transform. OpenCV implements this feature, check: Implementing SIFT in OpenCV.

Also these pages offer valuable content:

• Finding shapes in an image using opencv
• Are there any fast alternatives to SURF and SIFT for scale-invariant feature extraction?
• Sift implementation with OpenCV 2.2
• training SIFT features in OpenCV