21–28 of 28 posts
Why does this sound like the real version of "Zoom. Enhance."
... and always wait for macho boss to come in and give those instructions because the hackers would never think to do that
I'm curious if you could DIY the mask used for example in FlatCam that they mention, it looks a really interesting area. Apparently for the mask they use "a custom-made chrome-on-quartz photomask that consists of a fused quartz plate". I was wondering if you could make a very poor equivalent through just acetate and printing. It vaguely reminds me of an old fashioned technique such as: https://en.wikipedia.org/wiki/Z…
You can actually just place a random diffuser directly on a sensor -- this is work from some colleagues at UC Berkeley which I (surprisingly) didn't see mentioned in this article https://www.medgadget.com/2018/01/diffusercam-lensless-3d-im... DiffuserCam was previously discussed on HN but I couldn't find the link.
Earlier quoted context omitted.
Would it be as simple as imaging a point with the system and using that as the source for the PSF?
more or less; the flatcam paper has a section on the calibration method (finding the psf)
http://web.media.mit.edu/~raskar/Mask/
About halfway down the page you can see the out-of-focus point source looks identical to the coded aperture.
While not lensless photography, this seems like a good starting point for those interested in these techniques, especially if I can load the PSF into ImageJ.
Why does this sound like the real version of "Zoom. Enhance."
I used to dismiss those obvious Hollywood cliches, but the more I looked into the space professionally, the less silly it sounds. Images-as-data are far richer than images-as-images, it turns out, and clever algorithms can extract a lot more information from them than you would naively expect. So yeah, you're right!
I had the impression that images are data, hehe
As I understand, one of the biggest costs of optical telescopes is the mirror, which needs to be meticulously ground to a paraboloid. Ever since I was a child, I always wondered if we could use a semi-cylindrical mirror (which is much easier to fabricate) to focus light into a linear sensor array and achieve the remaining focus computationally. If this is possible, we might be able to build much larger, cheaper versi…
As I understand, one of the biggest costs of optical telescopes is the mirror, which needs to be meticulously ground to a paraboloid. Ever since I was a child, I always wondered if we could use a semi-cylindrical mirror (which is much easier to fabricate) to focus light into a linear sensor array and achieve the remaining focus computationally. If this is possible, we might be able to build much larger, cheaper versi…
https://www.youtube.com/watch?v=_8sd9UgjXLE
I'm sure that durabililty would be an issue, and the vacuum would probably leak over time without some significant effort, and it probably wouldn't be very stable under environmental changes, but it's a cool lateral solution.
Just yesterday someone was telling me about using diffraction for imaging. He also mentioned the work of Laura Waller, who apparently is able to get 3D images of a scene by putting translucent-but-not-transparent tape directly over the lens-free sensor. It seems the idea is that each point source of light has its own caustic pattern.
Just yesterday someone was telling me about using diffraction for imaging. He also mentioned the work of Laura Waller, who apparently is able to get 3D images of a scene by putting translucent-but-not-transparent tape directly over the lens-free sensor. It seems the idea is that each point source of light has its own caustic pattern.
A talk was given at the last CCC about free electron lasers, and in it the speaker talks about using diffraction to image chemical reactions. It's great watch. https://media.ccc.de/v/34c3-8832-free_electron_lasers