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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

#131

Post by eclipxe »

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…

Thank you for saying what I'm sure a lot of us were thinking.

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

#132

Post by voltagex_ »

jpap wrote: post #60
gandalfu wrote: post #59

It takes time and lots of effort, and ill argue is easier on a quasi standard platform (processor wise) but apps like this show how much juice can be squeezed out of the existing hardware by handcrafting the code. Kudos, I just bought the app!

Thanks for the download! Let me know if you've got any feedback, I can be easily contacted through the app. :D I'd just like to add that in addition to handcrafted code, choosing the right algorithm and always trying to "do less work" (less cycles, less data IO, better use of registers) makes a big difference.

I'd love to make the jump from "just" web development to some proper embedded development. Any pointers?

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

#133

Post by jpap »

zxcdw wrote: post #128
jpap wrote: post #118

Earlier quoted context omitted.

Thanks! :-) To be honest, none of my formal training prepared me for what went into SnappyCam---only the "how" to go about learning to do so. I'm sure you could pick up a few tricks in the same way by working on a cool pet project or two. With so many recent requests for AGIF, I'm absolutely going to add it to the app. (It's been on my list for a while, but lower priority than getting up a solid core product and the…

Out of curiosity, what kind of educational background do you have if you don't mind the question? As a highschool dropout it interests me. :)

I'm Aussie, so I did my schooling in Melbourne, Australia.

I don't recommend the same path for everyone, but my ugrad at RMIT University, dual bachelors of EE and CS. I then went on to do a Ph.D at the University of Melbourne in EE. My dissertation was on mathematical optimization of wireless and wireline DSL. (Prof Jamie Evans is an awesome guy if you're on the lookout for an advisor!)

I've been in SFO for just over 5.5 years, and started SnappyLabs after winning the "greencard lottery".

SnappyCam, you might say, is the embodiment of both a very practical ugrad and somewhat applied but very theoretical pgrad.

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

#134

Post by voltagex_ »

jrockway wrote: post #124

What's the breakthrough? My GoPro can take 120 photos per second. Futhermore, what happens if you point this at a device that can affect each pixel on the phone's image sensor 20 times a second? Is all the information preserved? If so, this is an interesting hardware hack. If not, this is an interesting shell game. But I don't see how it's a scientific breakthrough. (It sure is good for sales when TechCrunch prints y…

The breakthrough is in some very fast signal processing to allow the images to be taken on an iPhone, not a GoPro. Both are impressive.

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

#135

Post by reeses »

damian2000 wrote: post #37

I'm interested to know how their method compares to how dedicated digital cameras and DSLRs do it? are cameras running dedicated hardware/firmware to achieve the same result? Or have they optimised their software in the same way that SnappyCam has done it?

When you read about 'DIGIC', 'BIONZ', or 'EXPEED' in dedicated digital cameras, you're on the spot with custom processors. (In some cases, more than one) They're often multi-chip modules that can be scaled depending on the level of camera and can be based on standard SoC or embedded macros.

On top of that, you'll have the 'firmware', which is where projects such as Magic Lantern/CHDK make things fun.

Some reading on the Canon gear:

http://cpn.canon-europe.com/content/education/infobank/captu...

http://magiclantern.wikia.com/wiki/Datasheets

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

#137

Post by icebraining »

jpap wrote: post #53
marcamillion wrote: post #50

Earlier quoted context omitted.

Do these work for you? When I load the site, I see the photo scrub on the right hand side of the screen - and the slider moves up and down...but I don't see the big image loaded in the center of the screen where I expect the image to be. Unless it takes a while to load - in which case I was just being uber impatient.

I saw this a couple of days ago. Are you using Chrome? It might be yet another Chrome canvas bug. :-( Try Safari and let me know if you can? :-)

Works fine in Firefox, FWIW.

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

#139

Post by jpap »

huhtenberg wrote: post #129
jpap wrote: post #126

Earlier quoted context omitted.

Thanks for the suggestions: 1. Looks like a race condition for the settings button tap. Does it happen if you wait a second before pressing the settings button? 2. You can re-enable the tutorial (overlay) screens from the bottom of the settings menu. 3. On the usage/reports, I hear you. I won't give you bullshit on "standard industry practices" here, but I will say that I had to hack a well-known closed-source librar…

"Ask" should be the default, I have to insist. Just tried the actual functionality and it gives the machine gun sound effect, showing a counter going up to 50-60, then I release the button, the blue stripe around the button shrinks back, it adds a photo to the bottom-left area, but when I tap it, there are just 3 frames. What am I missing? Is it adaptively trimming bad frames (I am shooting in a low light conditions)…

Yes, that does require some explanation:

1. The receding circle is the capture buffer being processed. When you're tapping on the thumbnail, SnappyCam sees the start of the living photo being available and shows it. It does not, unfortunately, refresh the thumbnail list as more shots complete processing.

This is a (feature) bug and I'll work to address it.

2. The circle with percent progress is what I call "turbo rewind", where the camera is shut down so that all CPU cores can be applied to compression so that you can take back-to-back living photos quickly.

You can select the buffer "threshold" for when this kicks in under the advanced settings: look for Turbo Rewind.

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

#140

Post by wmf »

jrockway wrote: post #124

What's the breakthrough? My GoPro can take 120 photos per second. Futhermore, what happens if you point this at a device that can affect each pixel on the phone's image sensor 20 times a second? Is all the information preserved? If so, this is an interesting hardware hack. If not, this is an interesting shell game. But I don't see how it's a scientific breakthrough. (It sure is good for sales when TechCrunch prints y…

A GoPro can do 720p (1 megapixel) at 120 FPS; this app can do 8 MP at 20 FPS. Also, it's using JPEG instead of a video codec so when you want to pick out a single frame it's already in the format you want. Likewise there are no motion artifacts because it doesn't use a video codec, so every frame should be equal quality.
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