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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

#131

Post by acjohnson55 »

georgemcbay wrote: post #76
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…

On a slightly related tangent, every time I see someone post a "#nofilter" photo on facebook I have to bite my tongue to stop from asking them how their camera managed to separate the RGB channels without a Bayer (or similar, eg Foveon) filter. I mean, I sort of get what they are saying and I hate the overuse of Instagram filters probably much more than the next guy, but the odd relevance people place towards getting…

I appreciate #nofilter. Color correction and enhancement is one thing, but not every selfie or food pic needs to be antiqued. Most filter usage seems to be an attempt to cover up crap lighting and careless composition with "irony".

Re: Lens Blur in the new Google Camera app

#132

Post by grecy »

acjohnson55 wrote: post #125
jawns wrote: post #41

Earlier quoted context omitted.

When you say "digital edits are seriously banned," I think that's overreaching. I'm a former newspaper editor, and "digital edits" in the form of adjusting levels, color correction, etc., are performed on every single photo. What's not allowed, as you allude to, is retouching a photo. So does introducing blur after the photo was taken count as retouching, or does it fall into the same category as color correction? It…

Those permitted edits you mention seem to all preserve the pixel-level integrity of the image. The fact that intentional blurring does not do this seems to be a distinction to me. I think that the fact that the blur layer must be synthesized heuristically indicates that not all of the information of the final image was really captured from the real world. I suppose that resizing (resampling) an image might be said to…

>Those permitted edits you mention seem to all preserve the pixel-level integrity of the image.

Curiously, you're allowed to convert color to black and white, which in my opinion is not preserving the pixel-level integrity. An algorithm is making a guess at what level of black to convert a pixel to.

> Question for professionals -- how are noise reduction, masks (unsharp), etc. treated?

I'm not a pro yet, but my understanding is it's a big no-no.

Re: Lens Blur in the new Google Camera app

#133

Post by piyush_soni »

kbrower wrote: post #78

I did a quick comparison of a full frame slr vs moto x with this lens blur effect. I tried to match the blur amount, but made no other adjustments. Work really well compared to everything else I have seen! http://onionpants.s3.amazonaws.com/IMG_0455.jpg

Humm ... Looks only 'ok-ish' to me ... Though I've done some experiments (no DSLR here) just with people, and it looks good there.

Re: Lens Blur in the new Google Camera app

#136

Post by devindotcom »

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…

Getting a good alpha channel around objects is pretty hard live and with high megapixel counts. If you want to do this in-camera or within half a second, it's going to be sloppy for now. Essentially you have to check out a bunch of different 'magic wand' settings and compare the results, and there's no validation of those results until the user sees them. But yeah, it should definitely be possible to scoot the blur point "backwards" a bit.

Re: Lens Blur in the new Google Camera app

#137

Post by kordless »

mikeleung wrote: post #65
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

Using the app it feels like it knows how much you are moving it, which would indicate it's not taking more 'pictures' but actually building a depth map for the first image it takes.

Re: Lens Blur in the new Google Camera app

#138

Post by tsunamifury »

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…

Ex-photojournalist here:.

The data that the photo conveys should not be edited (i.e. the people in it, the objects in it, the framing shouldn't be used to intentially remove relevant data to the subject etc) but the mood or style of the photo may be edited. Colors, contrast, some stylistic effects, lighting, depth of field etc.

Its fairly obvious whats over the line and what isn't in 99% of cases with this.

Re: Lens Blur in the new Google Camera app

#139

Post by micampe »

sliverstorm wrote: post #38
aray wrote: post #33

Earlier quoted context omitted.

Could you speak to how familiar photojournalists are with the math and transformations that take place inside a digital camera? For example, almost certainly your cameras have dead pixels, which are processed away during the demosaicing stage, but showing them would be a "straight off the camera image" that I doubt any photojournalist would desire. Additionally many scene-wide process steps (like lens shading map est…

It sounds like the problem isn't image processing, the problem is image processing by the photojournalist , because with Photoshop in hand they can change the meaning of the photo. The best way to avoid that, is to avoid the use of Photoshop.

It’s an age old topic really, what you are doing with the camera is representing what you see, you are cropping a small part of what’s around you, and you can give something completely different meanings by just pointing the camera in a different direction.

Re: Lens Blur in the new Google Camera app

#140

Post by coin »

Shallow depth of field is so overused these days. I much prefer having the entire frame in focus, and let me decides what to focus on. I understand the photographer is trying to emphasize certain parts of the photo, but in the end it feels too limiting. It's analogues to mobile "optimized" websites - just give me all the content and I'll choose what I want to look at.
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