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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

#191

Post by cclogg »

stan_rogers wrote: post #185
cclogg wrote: post #113

Earlier quoted context omitted.

Regarding no filters, I've been shooting on 35mm film for the last year and been really enjoying it, almost never have to color correct, and the photos look so damn good! (especially skin tones) I just do develop + scan at the drug store, no prints lol. Doesn't work for everyone though, as waiting a day for photos might not be ideal (but I enjoy the anticipation heh).

That's actually massively filtered most of the time. The colour corrections are done at scan time (just as they were at print time with standard photofinishing in times past). If you were developing/printing in a home darkroom in ye olde days, you'd expect a good print on the third sheet of paper (well, the 2.25th sheet, since you'd only use a quarter-sheet for the rougher adjustments) after fiddling with filter pack…

Yes, regarding the scanning, this is true... I will say though that I've tried photographing (digitally) my own negatives to see how similar it was to a drug-store scan, and it was pretty close color-wise.

However, I would have to disagree about skin tones unless you can provide some examples to sway me. I've googled a lot of comparisons and have yet to see one that looked as good. I find that the way digital captures just makes the skin look quite harsh, and reveals flaws. I personally think digital needs to make more changes to the sensor itself to really step up the quality. Foveon is an awesome example, but not fully there yet in my opinion.

Re: Lens Blur in the new Google Camera app

#192

Post by caycep »

mark-r wrote: post #167
caycep wrote: post #120

Earlier quoted context omitted.

Eh...$15 used 50mm f1.4 or F2.0 lens and $25 film body from KEH.com...

And how are you going to fit that into your pocket? Good luck getting that film to Instagram too.

The point is, it's not difficult at all, and the optics setup to do so is actually much simpler than the computational algorithms needed to do it digitally. To think that an expensive DSLR or complex PGM algorithm is required to do so is silly. People have been shooting narrow DOF pictures for most of the past century.

Now to get smartphones to do it is perhaps harder than running out to the store and getting a camera, but I would characterize this as one of those evolutionary rather than revolutionary improvements.

In terms of digitizing, there's this archaic thing called a scanner, but a lightbox/DSLR rig can do it, but with the rise of full frame/narrow/mirrorless bodies from Fuji and Sony, you might not even need to do that anymore...

Re: Lens Blur in the new Google Camera app

#193

Post by jheriko »

This sounds clever but also massively complex for what it does. I don't have anything finished but I can think of a few approaches to this without needing to reconstruct 3d things with clever algorithms... still very neat visually if technically underwhelming

Re: Lens Blur in the new Google Camera app

#195

Post by jheriko »

cclogg wrote: post #191
stan_rogers wrote: post #185

Earlier quoted context omitted.

That's actually massively filtered most of the time. The colour corrections are done at scan time (just as they were at print time with standard photofinishing in times past). If you were developing/printing in a home darkroom in ye olde days, you'd expect a good print on the third sheet of paper (well, the 2.25th sheet, since you'd only use a quarter-sheet for the rougher adjustments) after fiddling with filter pack…

Yes, regarding the scanning, this is true... I will say though that I've tried photographing (digitally) my own negatives to see how similar it was to a drug-store scan, and it was pretty close color-wise. However, I would have to disagree about skin tones unless you can provide some examples to sway me. I've googled a lot of comparisons and have yet to see one that looked as good. I find that the way digital capture…

It's almost certainly the other way around esp. by your description of 'harsh' skin. Likely something lossy in the film process gives the effect you like (if it is even real... it's easy to imagine all sorts of visual differences that aren't real when you know stuff)

Re: Lens Blur in the new Google Camera app

#197

Post by pollen23 »

anoncow wrote: post #135

How is Nokia Refocus similar or different to this? It allows refocusing a part of the image which blurs out the rest.(Not a pro) https://refocus.nokia.com/

Nokia Refocus is quite different.

Refocus is a set of photos with different focal lengths, and a look up table.

For each "pixel" (The look up table isn't full resolution) the look up table tells which of the photos has the most variance (i.e., is the most focused) at that point, and the viewer simply switches the photo that's shown.

Re: Lens Blur in the new Google Camera app

#198

Post by joshuak »

jychang wrote: post #154
kbrower wrote: post #87

Earlier quoted context omitted.

They did hire Marc Levoy. I have been hoping for this for awhile. Can't wait for the next iteration. There are certain things you can't replicate with just a single tiny camera, but they are doing a great job! https://news.ycombinator.com/item?id=6483182

> There are certain things you can't replicate with just a single tiny camera MOST DoF and bokeh effects in photography can't be replicated with a single small camera. As a photographer, bokeh is surprisingly difficult to fake, and looks glaringly bad when you notice. The blur effect is due to focal distance ratio differences, and it's very difficult to determine the distance in software. Hell, it's hard to determine…

Very true. We do this kind of work in VFX all the time to reduce CG rendering costs for blurs that are expensive in 3d but cheap in 2d. Even with access to sub pixel (4x, 8x etc.) depth maps there are always lots of issues to deal with around edges.

But given that jpeg is good enough for most people I'm sure these types of tools are too.

Re: Lens Blur in the new Google Camera app

#200

Post by joshuak »

mark-r wrote: post #166
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…

I think the magic here is the generation of the depth map. Decently convincing blurring has been available for a long time.

The depth part is actually much easer than you might think and we've had techniques for doing some aspects of it since the 80's if not earlier.

One early technique was to take video form a mounted camera moving horizontally on weals looking 90 degrees to the side from the direction of travel (think looking out the side car window).

Now if you take that sequence of video frames and stack them one after the other like a deck of cards to create a 3d volume. Then you look down on that volume, what you will see are lines of color moving diagonally. Top left to bottom right, or the other way depending on your direction of travel.

These are the image features as they trace there way across the video over time. Things that are close move quickly so have a shallow diagonal. Things that are further away move slowly and have a much steeper diagonal.

Assign a depth to slope, done! Who needs LiDAR.

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