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Extreme imaging using cell phones: SeeInTheDark [pdf]

graphics.stanford.edu

21–26 of 26 posts

Re: Extreme imaging using cell phones: SeeInTheDark [pdf]

#21
post #16

Nice PDF. Some cool new stuff, smart decisions & remarks (noise, hotpixels, matching frames, etc). If you have an iOS device, check out the app Average Cam Pro[1]. I've had it on my iPad for several years now. It does an awesome job taking noise-free, detailed pictures (as long as you don't hold it in your hand) by taking up to 100 pictures and merging them. You can adjust exposure etc. after the fact. Great stuff. I…

I just installed average camera pro. Very blurry. Not useful for indoor photography. Does not allow for adjustment of the shutter speed. Don't buy. It's Nothing like what the paper describes.

Operator error. Like I said, it's not for handheld use (the only way to get blurry shots).

Correct way:

- Settings: Set the number of shots to 32 or higher. 1s interval. 3s pre-start timer

- Point at scene. Lean it against an object (don't touch/move) or mount on a tripod.

- Select exposure/focus/whitebalance with longpress (I select a light part of the scene, exposure/gain can be adjusted upward afterwards).

- Lock exposure/focus/whitebalance (could be an L in the middle, or text on your screen left, boldface is locked in)

- Shoot.

- After it's done (don't touch!) adjust the exposure if needed.

====

If you want even higher quality images, you can subtract banding noise (also mentioned in the PDF by the way).

In order to get the banding noise image for your camera:

- set shots to 128, delay 5 seconds

- point lens at light source (e.g. on table, don't move)

- hit shoot, put piece of white paper over the lens

- wait ~2mins (till it stops shooting).

- Select N in middle, "save image as noise fingerprint".

Then take another shot of a scene. Once final pic shows, hit N, now say "remove banding noise".

Re: Extreme imaging using cell phones: SeeInTheDark [pdf]

#22
post #16

Nice PDF. Some cool new stuff, smart decisions & remarks (noise, hotpixels, matching frames, etc). If you have an iOS device, check out the app Average Cam Pro[1]. I've had it on my iPad for several years now. It does an awesome job taking noise-free, detailed pictures (as long as you don't hold it in your hand) by taking up to 100 pictures and merging them. You can adjust exposure etc. after the fact. Great stuff. I…

I just installed average camera pro. Very blurry. Not useful for indoor photography. Does not allow for adjustment of the shutter speed. Don't buy. It's Nothing like what the paper describes.

@ricw - here, a very quick and dirty comparison, iPad3, dirty keyboard, watch, focus/exposure locked on rim of the watch.

https://goo.gl/photos/9FM2c9JZRcDitPdd6

Watch full screen for best comparison. Taken in dark office, with just a desk light.

Re: Extreme imaging using cell phones: SeeInTheDark [pdf]

#23
post #14

Earlier quoted context omitted.

Another mirror in case it goes over the dropbox limit: http://files.jjcm.org/seeinthedark-public-15sep16.key.pdf

Thanks, it did :)

I just want to say, I only came for the comments, but clicked after seeing people report so many downloads that it went over your rehosting limit.

The pictures in the PDF are absolutely stunning. I encourage everyone to have a look.

If anyone needs a quick spoiler (a pair of comparison images I copied from the PDF into a gallery for you) here you go:

http://imgur.com/a/THJbf

Re: Extreme imaging using cell phones: SeeInTheDark [pdf]

#24
post #11

Hubble - does it take one long exposure or similarly multiple short ones?

A bit of both. Hubble can have single exposures that are hundreds of seconds long - but remember it's in low orbit, so eventually the subject will fall beneath the horizon. Most Hubble observations stitch together exposures from multiple orbits. Ultra Deep Field is an extreme example which comprises ~a million seconds of exposure over 400 orbits: https://en.m.wikipedia.org/wiki/Hubble_Ultra-Deep_Field

In astronomy you need multiple exposures to get rid of cosmic rays, which appear as bright lines or dots. A median filter can be applied to the exposures. HST uses tools called drizzlepac and multidrizzle to combine multiple dithered images to better make use of the telescope's native resolution which would otherwise be degraded by the detector.
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