Lack of sleep is taking a toll on me. I can’t focus on things, I tend to be less positive than I could.. and my under eye bags are getting worse. Of the recent pictures that have been taken of me, I can only keep those where I wear sunglasses. I’ve been doctoring pictures before, to fix the tired look on my face … 8) … but that’s not a solution. The truth is that I need to sleep !!
Right now I’m using Crimson Editor to edit this post. I found out that it has a spell checker. Great ! But the real reason why I’m not editing within GMail is that I need a custom black background to lessen the pain on my eyes.
A few months ago I tried some popular sleeping pills that can be bought here in Japan. Unfortunately, those don’t seem to help in getting me convinced to fall asleep. They did give me some solid dreams, but as far as getting me quick to sleep.. not a chance.
On a different note. I’ve been looking around image processing, a field that interests me very much. This relates to improving image quality of Aibo, but also to video-compression. One very fascinating thing is how a thumbnail can look decent at its own resolution, but look terrible when stretched. Obviously all the “information” introduced by (usually) bilinear filtering is largely spurious.
I’ve been working on a better re-sampling algorithm for my next video-chat software. It’s nothing too new. Basically, I try to individuate the logical direction formed by adjacent pixels rather than blidly interpolate rows and columns.
Here is an example, on the left is a portion of an image down-sampled to 50% and then up-sampled back to the original size, using The Gimp (which probably uses bilinear filtering), on the right my up-sampling:

Bilinear up-sampling	Cheap 2×2 matrix up-sampling

A lot more can be done. Specifically, working on sub-matrices of 2×2 pixels, like I’m doing, is still not nearly good enough. A better re-sampling should try to individuate edges and shapes in an image and preserve those features as much as possible. Ultimately, the best result would come out of an algorithm that has somewhat experience and can at some level understand what the contents of the image are, and fill the missing pixels at re-sampling time, with those that fit the algorithm’s experience. This is what our brain does, and that’s why we can “zoom” image thumb-nails in our mind, much better than bilinear or trilinear filtering do 8)

Posted by Davide Pasca in Uncategorized