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Scientific Breakthrough Lets SnappyCam App Take 20 Full-Res Photos Per Second

techcrunch.com

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Re: Scientific Breakthrough Lets SnappyCam App Take 20 Full-Res Photos Per Second

#251

Post by prawn »

megablast wrote: post #205
prawn wrote: post #148

Earlier quoted context omitted.

Congrats fellow Australian. Two of us here in an office in Adelaide just bought the app. Guy behind me said "Hey, this is pretty cool. Have you seen... oh, you're looking at it already."

Hi, what is Adelaide like to work in? I assume you guys are in IT? From what I hear, it is mostly government work.

I run a two-person web development business and have worked out of Adelaide for myself for 15 years. Always seems to be enough work around and a decent amount of variety.

The other SnappyCam purchaser I mentioned is an iOS/Android developer who is a sub-tenant in my office. We actually have a cheap, spare desk in this room at the moment if you wanted to visit and work for a while. Email me if you want to ask any questions.

Re: Scientific Breakthrough Lets SnappyCam App Take 20 Full-Res Photos Per Second

#252

Post by groby_b »

jpap wrote: post #172
dlsym wrote: post #163

Earlier quoted context omitted.

Does not work in FF 22.0, neither in Chrome: 28.0.1500.71 or Opera. (OS: Linux Mint)

Ouch. Looks like some work for me ahead. The problem with Chrome 28.0.1500.x (.95 here) is troubling me. It seems a more recent problem that I'm convinced is another browser bug. Thanks for the detailed version report, that's really going to help. :-)

Hm. Works on Chrome 30.0.1582.0 (Canary) - after repeated page refreshes. Was stuck on 98% several times. Disabling the cache doesn't allow me to repro it, emptying the cache doesn't either.

Works with 28.0.1500.95, too.

However, looking at the console, I see occasional instances of Resource interpreted as but transferred as MIME type . Not a big deal, but maybe a pointer.

Re: Scientific Breakthrough Lets SnappyCam App Take 20 Full-Res Photos Per Second

#253

Post by portmantoad »

jpap wrote: post #16
revelation wrote: post #11

DCT is already lossy [1], so the statements around 8 megapixels are completely pointless, and worst of all, its 1990 lossy technology. Wavelet transformations completely destroy any DCT. That said, if their emphasis is on producing pictures with minimal time delta at highest resolution, algorithms used for still pictures are out of place. Video compression algorithms still use DCT and wavelets, but they do so only af…

You are right on the loss: it's purposefully introduced as a quantization step after performing the DCT, and before losslessly compressing the resulting coefficients with Huffman and encoding to the final JPEG bitstream. Despite all of that, JPEG has now become computationally tractable. I remember the days where it took tens of seconds to encode a JPEG on a commodity machine. Now, with the help of SIMD, we can encod…

One thing I've gotten very into recently is multishot techniques, where I take multiple shots in burst mode, align them, and then average them to reduce sensor noise. Similar to what http://www.photoacute.com/ does but they do more advanced superresolution stuff that your invisible noise might preclude, but a simple average or median in areas where there isn't too much motion really improves the quality quite dramatically in some cases, particularily in low lighting situations. If your frame rate is that high it probably wouldn't be hard to get a really good alignment between frames, so I thought I'd bring this up as a thought for a future feature (as in - you select the frame you like, then the program grabs a few frames immediately before and after and uses them to increase the image quality of the final output).

Re: Scientific Breakthrough Lets SnappyCam App Take 20 Full-Res Photos Per Second

#254

Post by jostmey »

This may be a really cool technical achievement, but the title is misleading. It is not scientific - that is, the scientific method was not applied to increase our understanding of the Universe. No, it is just a really cool testament to how cool engineering really is.

Re: Scientific Breakthrough Lets SnappyCam App Take 20 Full-Res Photos Per Second

#255

Post by bulte-rs »

jpap wrote: post #229
bulte-rs wrote: post #220

Earlier quoted context omitted.

Actually, cancer research can benefit (admittedly by a long shot, but still) by these kind of improvements in image processing. Don't forget that medical imaging and - thereby indirectly - the recognition/detection of cancer is one of the first steps in curing said disease.

Very well said. I suspect Clarity on Camera+ is some form of Contrast Limited Adaptive Histogram Equalization (CLAHE). CLAHE came about from digital image cleanup of medical scans for human analysis.

Now, a CLAHE implementation on top of SnappyCam .....

Re: Scientific Breakthrough Lets SnappyCam App Take 20 Full-Res Photos Per Second

#256

Post by PavlovsCat »

jpap wrote: post #5
wmf wrote: post #3

Earlier quoted context omitted.

Yeah, I'm kinda skeptical of the "science" here. Edit: A new algorithm counts as science, but the TechCrunch article really gave no justification for the claim.

I've given a bit more background to the fast JPEG codec on my engineering blog: http://www.snappylabs.com/blog/snappycam/2013/07/31/iphone-k... If you like signal processing, fixed point arithmetic, SIMD cores, and assembly, then this is for you. :-)

I find it amazing how you share your know-how so freely. This is the first app I ever saw that made me think of an iPhone as a potentially desirable thing... not enough to make me get one, but a big compliment to you. Never change (unless it's for the even more generous and clever of course :P)

Re: Scientific Breakthrough Lets SnappyCam App Take 20 Full-Res Photos Per Second

#257

Post by jpap »

zeroDivisible wrote: post #233

I must say that this is one of the most interesting apps which I had found in last few weeks. You should get yourself a beer as this is a neat feat to accomplish:) Also, some people were saying that webapp wasn't working for them on some chrome versions. As for me - I've got the 28.0.1500.95 - the culprit was Disconnect extension, which when disabled, allowed the whole application to behave as expected.

That really helps, thanks for letting me know about the disconnect extension. I've never used it, will check it out.

Re: Scientific Breakthrough Lets SnappyCam App Take 20 Full-Res Photos Per Second

#259

Post by jpap »

bulte-rs wrote: post #255
jpap wrote: post #229

Earlier quoted context omitted.

Very well said. I suspect Clarity on Camera+ is some form of Contrast Limited Adaptive Histogram Equalization (CLAHE). CLAHE came about from digital image cleanup of medical scans for human analysis.

Now, a CLAHE implementation on top of SnappyCam .....

I considered doing this over a year ago. I was really intrigued by the algorithm and declared it was a distraction over getting the basic app solid first.

I'd love to revisit it. It really works wonders. I've played with the CLAHE implementation in Fiji/ImageJ and while it can produce really good results, it does require some tuning.

I really admire the Camera+ guys for creating an auto tuning algorithm that is quite similar. (I'm unsure if they're using CLAHE or a variation.)

Re: Scientific Breakthrough Lets SnappyCam App Take 20 Full-Res Photos Per Second

#260

Post by jpap »

ajpocus wrote: post #242

jpap, this is the best HN thread I've seen in a while. I never comment, but I'm compelled to now, because it's not often I see a hack this mesmerizing and exciting. For a moment, I almost wanted to drop everything and dive into JPEG myself, something I don't think I've felt since reading about John Carmack and his game engine hacks. Even though I understand <10% of the details being discussed, I'm compelled to learn…

I'm so very happy to read your post! :-)

I'm not usually one to post publicly either, but with practice I'm finding it comes more naturally.

I do hope you dive in---the devil's details in image signal processing is really interesting.

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