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

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

#241

Post by stefantalpalaru »

nl wrote: post #216
stefantalpalaru wrote: post #189

Earlier quoted context omitted.

The Android bashing in that article is unfounded: http://www.eggwall.com/2011/09/android-arm-assembly-calling-...

It's not Android bashing - he's managed to make the older, slower iPhone hardware perform better than the current high-performance kings (the S3 & S4) through smart software optimisation. There's no reason he couldn't do the same on Android and see similar gains. It would just be a lot of work..

He only implemented his optimized software on one platform and somehow starts to compare it with different software on another platform. How is that relevant for that other platform's performance?

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

#242

Post by ajpocus »

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 more. Thanks, jpap. :)

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

#243

Post by gruseom »

philhippus wrote: post #203
revelation wrote: post #27

Earlier quoted context omitted.

It's just bizarre that you would be doing the complete JPEG process at the instant you get the image from the sensor. As you note, there are a plethora of steps that JPEG performs, from color space conversion, to DCT transformation (essentially a gigantic matrix multiplication), Huffman coding, quantization, arithmetic coding and encoding as JPEG bitstream. The only reason would be that you are pressed for memory or…

Why is this comment getting downvoted? I see that it adds insight to the subject and makes some good points, which OP even acknowledges. The written complaint is that revelation is not being deferential enough, which is bullshit on an in-depth technical discussion.

"Deferential" has nothing to do with it. In a technical discussion, the focus should be purely on the content. Inserting one's self into it (such as by being supercilious) detracts from that.

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

#244

Post by jasonwatkinspdx »

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…

> Wavelet transformations completely destroy any DCT.

It's not quite that simple. They have different strengths and weaknesses, so you can't say one is categorically better than the other. DCT has uniform frequency resolution, which sounds desirable but isn't once you start quantizing due to ringing, etc. See slide 25 or so of [1]. Wavelets overcome this problem by adapting the resolution in opposite ways at the extremes. This works fantastic for medium signal rates, but can have severe low passing at low rates. For low rate coding DCT with the bells and whistles (deblocking, etc) will typically win.

[1]: http://people.xiph.org/~tterribe/pubs/lca2012/auckland/intro...

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

#245

Post by ahknight »

jpap wrote: post #40
Oculus wrote: post #25

I have a feeling that soon SnappyLabs is going to have Apple knocking on their door with a very nice offer. Kudos to them, sounds like they deserve it.

Thanks! I just hope Apple's engineers don't get pissed off by the press. SnappyCam is built on their hardware, which can do remarkable things. Though we as app developers don't get access to a lot of their smarts, e.g. hardware JPEG codecs, I'm sure there's even more innovation in their work that often goes unacknowledged.

You'd think so, but they take 2-10s to recover from a photo and you ... don't. Clearly there's some room for optimization there. :)

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

#246

Post by i4software »

Hi Guys. This is Fast Camera. I'm callin' out SnappyCam!

Are you up for an old fashioned DUEL to see which app can shoot the most "native camera quality" 8MP images per second in 60 seconds without crashing?

On an iPhone 5 with all apps closed, SnappyCam manages to save only about eight 8MP per second over 10 seconds on average and loses the other 12 per second. And these are not 8MP images at least as far as comparing resolution against the native camera app or Fast Camera. All of this technical discussion sounds great but is anyone actually testing this like I am? Just download a stopwatch app with hundredths of seconds and burst for 10 seconds. You'll see. Then shoot something with a LOT of detail at 8MP in both SnappyCam and Fast Camera.

Fast Camera is capable of 10-12 native quality 8MP images per second (more than SnappyCam) We throttle it back on purpose.

And what's with camera-shutter.caf John? ;)

Michael Zaletel Founder, i4software Fast Camera, Vizzywig, Video Filters

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

#247

Post by zimpenfish »

gruseom wrote: post #84
revelation wrote: post #27

Earlier quoted context omitted.

It's just bizarre that you would be doing the complete JPEG process at the instant you get the image from the sensor. As you note, there are a plethora of steps that JPEG performs, from color space conversion, to DCT transformation (essentially a gigantic matrix multiplication), Huffman coding, quantization, arithmetic coding and encoding as JPEG bitstream. The only reason would be that you are pressed for memory or…

which would have been my first avenue in attempting to do something like this. Have you attempted to do something like this? Because he not only has attempted, he's done it. Therefore I think you should stop talking down to him ("completely pointless", "it's just bizarre", " my first avenue"). It comes across as wanting to prove how smart you are instead of seeking to learn from someone who has done incredible work a…

wild applause

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

#248

Post by lcrs »

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…

Re video's "studio swing" dynamic range, the YUV components do have a different encoding range to those in JPEG, but if you expand them back out to 0-255 the image is in fact the same - you lose a lil' fraction of your bit-depth but no dynamic range.

I think you definitely made the right choice though - it's interesting that the obvious delta-coding and motion compensation tricks to reduce bandwidth are rarely used for video acquisition apart from the most limited devices like phones, stills cameras and the GoPro. Everything that can afford to uses per-frame coding like ProRes, REDCODE, AVC-Intra, DNxHD, Cineform... being able to seek quickly is important!

In fact Canon's 1DC 4k camera uses (dun dun duhhhhh...) motion JPEG :)

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

#249

Post by prawn »

jpap wrote: post #188
robryan wrote: post #181

Earlier quoted context omitted.

Yeah, I think there is a niche for this. One of the main criticisms of vine is that there is a certain magic to pictures compared with video which comes off as more real. We don't want to save the reality of our lives, just the filtered moments. I really think this could fill a space in between the perfect single shot and the realness of video.

Glad to hear it. I feel the same on the format: it's closer to a photo on the left of the spectrum between photo and video, where vine/instagram/cinemagram are on the far right. You've put it very nicely--there's definitely some magic about a "silent moving picture". It requires and sparks the imagination in the viewer, evoking emotion perhaps as easily as a carefully crafted cinematic short.

It's also a photo with more context. If the presentation allowed the owner to pick the starting point, and users to slide forward and backwards, commenters could suggest other funny/interesting frames.

The work required to set up a basic social network around this would surely be insignificant when compared with what you've done to date! Yell out if you need help on the design side of things.

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

#250

Post by tptacek »

zimpenfish wrote: post #247
gruseom wrote: post #84

Earlier quoted context omitted.

which would have been my first avenue in attempting to do something like this. Have you attempted to do something like this? Because he not only has attempted, he's done it. Therefore I think you should stop talking down to him ("completely pointless", "it's just bizarre", " my first avenue"). It comes across as wanting to prove how smart you are instead of seeking to learn from someone who has done incredible work a…

wild applause

This whole thread should be framed and hung in the HN lobby.
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