stollcri

Indeed it is similar to seam carving. Which technique would you recommend for this task? Do you know of any other example implementations which can be run on a smartphone grade processor in near-real-time?

Yes, it is still young. The currently available version uses an edge detection algorithm which I designed for another purpose (text extraction), subsequent versions use techniques which are more appropriate for images. Also, the algorithm never refuses to square an image, even when there is a high likelihood of a poor result; I am experimenting with ways to visually communicate that to the app user.

I'm not a C# dev, but can't you just use simple bit masking?

You can share small chunks of code like this here: https://gist.github.com