tag:blogger.com,1999:blog-5246987755651065286.post707383272260242710..comments2021-09-23T06:05:09.002-07:00Comments on cbloom rants: 06-17-09 - Inverse Box Sampling - Part 1.5cbloomhttp://www.blogger.com/profile/10714564834899413045noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-5246987755651065286.post-37847181365193671582009-06-18T12:47:10.048-07:002009-06-18T12:47:10.048-07:00Yeah, I just cannot follow old signal processing p...Yeah, I just cannot follow old signal processing papers like that. I don't know WTF they're talking about.<br /><br />Anyhoo, I just did the brute force lsqr solve and I'll write it about next time I feel like blogging.cbloomhttps://www.blogger.com/profile/10714564834899413045noreply@blogger.comtag:blogger.com,1999:blog-5246987755651065286.post-67107968209795345962009-06-18T08:52:54.817-07:002009-06-18T08:52:54.817-07:00Oh, and if you want to search for things yourself,...Oh, and if you want to search for things yourself, you might want to search for "sample and hold compensation". As you can imagine, normally people are compensating for the case when the output filter is a box, not a tent. You get something like this, for example:<br /><br />http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=112588won3dhttps://www.blogger.com/profile/09787472194187459747noreply@blogger.comtag:blogger.com,1999:blog-5246987755651065286.post-71106777441770390882009-06-18T08:50:04.435-07:002009-06-18T08:50:04.435-07:00Well, I think the signal-processing solution to th...Well, I think the signal-processing solution to the preconditioning problem is rather straightforward. For example, I think it is common for digital filter designs to compensate for the DAC/output filter. I have a book on DSP stuff at home that I can dig up, or you could probably check that wacky text document Ryg posted a month ago.<br /><br />So if you have some target super-resolution, that means you know how big the tent is for your bilinear. What you want to do is figure out what the filter looks like to deconvolve that tent.<br /><br />Note a tent is just a box convolved with a box, so in fourier space, it is just a sinc modulated by a sinc -- so a tent has a sinc^2 fourier transform.<br /><br />So, I think your convolution filter should look like the inverse fourier transform if 1/sinc^2.won3dhttps://www.blogger.com/profile/09787472194187459747noreply@blogger.com