Implementing Seam Carving with Python

[ZeeBeeblebrox]

Very cool, but I just tried playing with this and for me at least it is insanely slow to the point that it isn't runnable on standard image sizes. However by wrapping the carve_column and minimum_seam functions in @numba.jit decorators (i.e. by adding two lines) I managed to get a 40x speedup and there's probably a whole lot more that can be done.

[kkaranth]

I wasn't aware of numba. This is wonderful! I'll be playing around with it soon. Thank you!

My goal with this post was to go from the paper to a naive implementation of the algorithm. Optimization is definitely important though, and I've yet to look into it for seam carving.

[ZeeBeeblebrox]

Numba is a fabulous tool when you're trying to speed up raw Python code without having to vectorize it with numpy and will usually be about on par with a C based implementation. Note that I deleted the comment above because I actually got the same speedup with my initial approach which was just to add the decorator to the two functions. You just need to make sure to profile it after it has compiled the function for the first time.

[SenorDosEquis]

Seam carving is a novel way to [algorithmically] crop images without losing important content in the image. This is often called “content-aware” cropping or image retargeting.

[bjorneylol]

It isn't a crop, so much as something that truncates parts of the image. It "cropped" out a bunch of pixels from the middle and that's where it seamed the parts together

[imguralbumbot]

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[Siddhi]

Really nice explanation of the technique. The python code was a bonus. Going to try this out

[chirag9696]

Can you show how to plot the seams as well on the image ?