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Lens Blur in the new Google Camera app

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Re: Lens Blur in the new Google Camera app

#121

Post by gomox »

Theodores wrote: post #109
gomox wrote: post #40

Earlier quoted context omitted.

Yes! It shouldn't be too hard to implement either, compared to depth detection.

Actually I would say it is a hard problem. Look at anything filmed in a studio against a blue/green screen. This is with perfect lighting, a perfectly racked camera, a proper camera tripod/dolly, a perfectly even background screen, the presenter wearing safe colours and anything else I forgot to mention controlled. Now look at the fine hair detail. Does it resolve too well in front of the keyed in ? Probably not. You…

It doesn't seem to be the same league of problem. Because you are going to blur the stuff in the background anyway, you can be agressive with the masking and the blurring will make it imperceptible. With blue/green screens you are making changes much more severe than just blurring (in terms of the colors, hues and shades involved).

Source: Hardly an expert, but I am quite a photography geek, and I've done some work on this type of graphical algorithms in the past (not this type of fancy 3D stuff though).

Re: Lens Blur in the new Google Camera app

#122

Post by aray »

kbrower wrote: post #84
aray wrote: post #51

Earlier quoted context omitted.

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…

Side by side comparison http://onionpants.s3.amazonaws.com/IMG_0455.jpg

Thanks! Great example. Does it look like the large camera is focusing a few inches back from the front of the ball and the Google Camera is sharpest at the center of the ball?

Edit: I was trying to look at the sharpness of features on the ball -- specifically the lettering on the left side.

Re: Lens Blur in the new Google Camera app

#124

Post by cfqycwz »

wooster wrote: post #37
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…

Yeah, it's complicated. On the one hand, you have dodging and burning, which were often used in actual darkrooms and are still used by respected photojournalists to increase the impact of their photos. [0] Then you have things like this: http://en.wikipedia.org/wiki/Adnan_Hajj_photographs_controve... Where clumsy and obvious use of the clone tool damaged the reputation of an entire news organization. The AP standards…

I'm curious to know why the AP don't allow red-eye removal--if the only manipulations allowed are those that help restore the clarity and accuracy to reality of the photographs, I'm not quite sure why red-eye removal wouldn't be permitted--most people's eyes, after all, are not red.

Re: Lens Blur in the new Google Camera app

#125

Post by acjohnson55 »

jawns wrote: post #41
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…

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 not preserve the integrity of the original pixels, but I think it does if you consider the original pixels to be a reflection of the continuous field at the sensor.

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

Re: Lens Blur in the new Google Camera app

#127

Post by kbrower »

aray wrote: post #122
kbrower wrote: post #84

Earlier quoted context omitted.

Side by side comparison http://onionpants.s3.amazonaws.com/IMG_0455.jpg

Thanks! Great example. Does it look like the large camera is focusing a few inches back from the front of the ball and the Google Camera is sharpest at the center of the ball? Edit: I was trying to look at the sharpness of features on the ball -- specifically the lettering on the left side.

Focus point of the large camera should be the exact center of the image. The center of the ball is a little out of focus as the center of the image is the top left of the ball. User Error :)

Re: Lens Blur in the new Google Camera app

#128

Post by taumhn »

vanderZwan wrote: post #69
raldi wrote: post #60

Earlier quoted context omitted.

> 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?

I'm pretty sure they definitely don't count, as DOF is a ratio of focusing distance IIRC. Also the DOF would be far more shallow with a DSLR and a fast lens in the same conditions (close focus).

Re: Lens Blur in the new Google Camera app

#129

Post by grecy »

sneak wrote: post #115
grecy wrote: post #98

Earlier quoted context omitted.

> 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. Yep, sorry. I was a bit rushed when I wrote my comment. I should have said "digital edits beyond basic color correction".

...and cropping.

Which is massively interesting, as I can walk forward effectively cropping the scene to remove (let's say) a car from the very bottom corner. I could use software to crop the image to remove the car, but if I use the clone tool to get rid of it, that's a big no-no.
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