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Lens Blur in the new Google Camera app

googleresearch.blogspot.com

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Re: Lens Blur in the new Google Camera app

#51

Post by aray »

dperfect wrote: post #26

I believe the algorithm could be improved by applying the blur to certain areas/depths of the image without including pixels from very distant depths, and instead blurring/feathering edges with an alpha channel over those distant (large depth separation) pixels. For example, if you look at the left example photo by Rachel Been[1], the hair is blurred together with the distant tree details . If instead the algorithm d…

I'd love to see some test images with that (just get a side-by-side with the app and a larger aperture camera).

As I understand what you're proposing, I'm not sure it would actually be closer to what a large-aperture camera would capture. The light field from the farther depth field should be convolving with the light field from the near depth field.

Still, side-by-side would be the best way to view these :) I'll do it later this weekend if I get the chance.

Re: Lens Blur in the new Google Camera app

#53

Post by aray »

nostromo wrote: post #48

I sure wish you could buy a DSLR that just plugs into your iPhone. I don't want any of that terrible DSLR software -- just the hardware. I think many devices should become BYOD (bring your own device) soon, including big things like cars. edit: I don't just want my pictures to be saved on my phone. I'd like the phone to have full control of the camera's features -- so I can use apps (like timelapse, hdr, etc.) direct…

They have large-aperture digital cameras that are similar already: http://store.sony.com/smartphone-attachable-lens-style-camer...

I'm interested why you'd want DSLR, though, because if it attaches to my phone i'd probably be happy to use the phone screen as the viewfinder and save the depth and weight that would otherwise go to a moving mirror assembly.

Re: Lens Blur in the new Google Camera app

#54

Post by QuotedForTruth »

nostromo wrote: post #48

I sure wish you could buy a DSLR that just plugs into your iPhone. I don't want any of that terrible DSLR software -- just the hardware. I think many devices should become BYOD (bring your own device) soon, including big things like cars. edit: I don't just want my pictures to be saved on my phone. I'd like the phone to have full control of the camera's features -- so I can use apps (like timelapse, hdr, etc.) direct…

Would a wifi enabled SD card work for you?

http://www.eyefi.com/products/mobi?lm

Creates a hotspot that your iPhone can connect to. Photos are then immeidately moved to your device as they are saved to the SD card by the camera.

I havent tried it, but Ive heard it works well for quickly sharing pictures. Downsides are cost compared to normal SD cards and battery use by your device.

Re: Lens Blur in the new Google Camera app

#55

Post by avaku »

kingnight wrote: post #30

I'd like to see an example of a evening/night shot using this. I can't imagine the results are anything like the examples here, but would love to be surprised. Are there more samples somewhere?

Next they should introduce an infrared laser for measuring depth like in Xbox, then is will totally work in the dark :)

Re: Lens Blur in the new Google Camera app

#56

Post by salimmadjd »

Is the app taking more than one photo? It wasn't clear in the blog post. AFAIU to have any depth perception you need to take more than one photo. Calculate the pupil distance (the distance the phone moved) then match image features between the two or more images. Calculate the amount of movement between the matching features to then calculate the depth.

As described you then map the depth into an alpha transparency and then apply the blurred image with various blur strength over the original image.

Since you're able to apply the blur after the image, it would mean the google camera always takes more than one photo.

Also a Cool feature would be to animate the transition from no blur to DOF blur as a short clip or use the depth perception to apply different effect than just blur, like selective coloring, or other filters.

Re: Lens Blur in the new Google Camera app

#57

Post by frozenport »

ISL wrote: post #15
jnevelson wrote: post #7

So Google basically took what Lytro has been using hardware to achieve, and did it entirely in software. Pretty impressive.

The difference is that Lytro actually does it, instead of simulating it. It'd be fun to play around with the software to see in which cases it breaks (perhaps taking a photo of a framed landscape photo with another landscape behind, for example)

In reality the Lytro has abysmal performance, which questions the value of lightfield technology as a whole.

Instead of capturing the 'light field' you may as well capture most of the image.

Secondly the loss of the 2nd derivative of the k-vector makes lightfield currently unsuitable for use in a microscope (although they are working on it...). Although there might be better techniques for refocusing, such as division in the spatial frequency domain.

see http://www.cnet.com.au/nokia-vs-lytro-the-refocusing-challen...

Re: Lens Blur in the new Google Camera app

#58

Post by avaku »

sp332 wrote: post #45
frenchman_in_ny wrote: post #8

Does this pretty much blow Lytro out of the water, and mean that you no longer need dedicated hardware to do this?

The Lytro images have a lot more data in them (although probably fewer pixels). You can move around slightly in a Lytro photo because it samples light from all directions. Also, Google's version doesn't seem to use the multiple exposures in the final photo. It only uses them to determine which pixels to blur in the first photo, and uses normal gaussian blur instead of simulating a lens.

It does simulate the lens, it says so in the article

Re: Lens Blur in the new Google Camera app

#59

Post by bronson »

JTon wrote: post #47
zippergz wrote: post #14

Earlier quoted context omitted.

It doesn't give me a headache, but to my eyes it isn't remotely convincing. There's no way I'd look at any of those example pictures and not realize the blurring was done with postprocessing.

I'm a photography layman and I really can't tell it was done with postprocessing. What gives it away for you?

The blur is far too uniform and boring. Actual bokeh has more intrigue to it: lens aberrations, crazy highlights, wonderful patterns, even when the depth of field isn't very extreme.

Check out some real examples on google image search: https://www.google.com/search?q=bokeh+examples&espv=210&es_s...

I'm impressed! Looks like Google solved the hard problem. Implementing a more pleasing blur than plain gaussian doesn't sound too hard.

Re: Lens Blur in the new Google Camera app

#60

Post by raldi »

jawns wrote: post #5

Regarding the technology (achieving shallow depth of field through an algorithm), not Google's specific implementation ... Up until now, a decently shallow depth of field was pretty much only achievable in DSLR cameras (and compacts with sufficiently large sensor sizes, which typically cost as much as a DSLR). You can simulate it in Photoshop, but generally it takes a lot of work and the results aren't great. The "sh…

> Up until now, a decently shallow depth of field was pretty much only achievable in DSLR cameras (and compacts with sufficiently large sensor sizes, which typically cost as much as a DSLR

In 2008, I had no trouble taking shallow-depth-of-field photos with a dirt-cheap Canon A570 pocket camera. For example:

https://farm3.staticflickr.com/2069/2076688334_aeae12583b_b....

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