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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

#61

Post by insickness »

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…

I recently got a Canon 6D. It has built-in wireless which allows you to connect directly to your smartphone so you can download photos from the camera to your phone. It works really well. You can also use your phone as a remote control to take photos and the view finder can be seen on your phone. I love that camera.

Re: Lens Blur in the new Google Camera app

#62

Post by sp332 »

avaku wrote: post #58
sp332 wrote: post #45

Earlier quoted context omitted.

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

Oh... well it doesn't do a very good job. The last example has her hair blurred where it should be sharp. That's not very lens-like.

Re: Lens Blur in the new Google Camera app

#64

Post by darkmighty »

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 think that case was just an imperfection of the depth map (the low depth area seems sightly larger than it should be)

Re: Lens Blur in the new Google Camera app

#65

Post by mikeleung »

salimmadjd wrote: post #56

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 a…

Yes, the app requires you to move the camera after your initial shot which takes another picture to calculate depth

Re: Lens Blur in the new Google Camera app

#66

Post by slaven »

salimmadjd wrote: post #56

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 a…

Yes - you have to move the camera upwards as it takes a series of photos. It is not working from a single photo.

Re: Lens Blur in the new Google Camera app

#67

Post by reustle »

grecy wrote: post #12

We had an interesting discussion about this a few nights ago at a Photojournalism talk. In that field, digital edits are seriously banned, to the point multiple very well known photo journalists have been fired for one little use of the clone tool [1] and other minor edits. It's interesting to think I can throw an f/1.8 lens on my DSLR and take a very shallow depth of field photo, which is OK, even though it's not ve…

> It's interesting to think I can throw an f/1.8 lens on my DSLR and take a very shallow depth of field photo, which is OK, even though it's not very representative of what my eyes saw

I beg to differ. Pictures with a shallow depth of field feel more real because that is how the eyes work naturally. Hold up your hand at full arms length, and focus on it with your eyes. Everything else around it is blurred.

Re: Lens Blur in the new Google Camera app

#68

Post by alanh »

aray wrote: post #51
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…

What do you mean, "the light field from the farther depth should be convolving with the … near"? Intuitively, grandparent post is right, the hair should be sharp.

Re: Lens Blur in the new Google Camera app

#69

Post by vanderZwan »

raldi wrote: post #60
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....

I'm not sure if zoomed-in macroshots "count", as they naturally have a more shallow DOF. Can you achieve the same effect with portrait shots?
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