This is an attempt to use RBF networks as interpolation for scaling up images. This may seem intractable for large images, but I will attempt to do it efficiently using conjugate gradients.
Resizing is very slow. On a 2.6GHz Intel Core i7, it takes about 8 seconds to resize a 30x36 image using a variance of 2.
RBF networks don't do much better than conventional interpolation algorithms for image resizing. I resized a 30x36 image to get some comparisons:
| Original | Preview.app on OS X | RBF with σ=1 |
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Here is a larger 120x120 image scaled up to 240x240. Interestingly, you will note "ripple-like" artifacts on the RBF image.
| Original | Preview.app on OS X | RBF with σ2=1.5 |
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