The Image Processing Corner

Introduction

With the wide spreading of numeric cameras, numerous image touch up processings are applied: color correction, sharpness enhancement, noise reduction...

A less known process, because more complex (and without guarantee on the result), this is not a "Harry Potter" filter...), is the automatic alteration of the image content. This section deals in particular with undesirable object removal from an image, like a pole for instance.

Another example of loosed picture, eventually nice. No, I did not open the bars afterwards: look at the lock still present !

This process has 3 steps :

• Manual selection of the undesirable zone.
• Manual or automatic (band around the undesirable zone) selection of a "source" zone, which content will provide the elements to replace the undesirable zone.
• Launch of the algorithm

The principle of the algorithm is to whittle down the undesirable zone until disappearance by pasting pixel patches from the source zone so that they maximize the similarity with the "valid" border of the contour of the undesirable zone.

For further details, see:

PatchWorks: Example-Based Region Tiling for Image Editing

Region Filling and Object Removal by Exemplar-Based Image Inpainting

Image Repairing: Robust Image Synthesis by Adaptive ND Tensor Voting (PDF)