Lens Blur in the new Google Camera app • Hacker News Board

Re: Lens Blur in the new Google Camera app

#241

Post by e12e » Thu, Apr 17, 2014, 10:48 PM UTC

thezilch wrote: post #203

jychang wrote: post #154

Earlier quoted context omitted.

> 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…

Unfortunately, as a non-professional photographer, I think this article very disingenuous. Most of the shots aren't taken from the same distance, angle, nor lighting. "Here we are, closer to the subject and from a different angle; notice that we don't have to deal with distinguishing our focused subject from subjects that no longer exist!" "Sure these look the same, but this one is done with optics and is definitely…

They're clearly taken with the same lightning (outdoors and around the same time), but with different iso/aperture/exposure -- as they would have to be. The dedicated camera will let in much more light than the phone camera.

I do agree the zoom/distancing on the "foliage" photos are unfortunate for comparison -- but the fluffy animals more than make up for it IMNHO.

Re: Lens Blur in the new Google Camera app

#242

Post by e12e » Thu, Apr 17, 2014, 10:56 PM UTC

shawabawa3 wrote: post #224

angusb wrote: post #222

Earlier quoted context omitted.

One limitation of this that nobody has mentioned yet is that if you have to pan your cameraphone as you are taking the photos to generate the depth map you will have a harder time composing your photo than you would with a traditional photo. Usually I like to spend a few seconds getting into the best position and framing my photo carefully before taking it. Getting the photo I wanted would therefore be much harder if…

You first take the picture normally. After taking the picture it asks you to slowly move the camera up to generate the depth of field, so there's no moving the camera as you're taking it

It would seem that if you have to do a depth scan anyway, it should be possible to just do a (series of) scan(s), and then post-compose and post-focus your image(s)?

Re: Lens Blur in the new Google Camera app

#243

Post by lloeki » Fri, Apr 18, 2014, 9:33 AM UTC

shawabawa3 wrote: post #226

angusb wrote: post #225

Earlier quoted context omitted.

Ah cool, so not a problem. Out of interest how long does the camera-moving step take?

> Out of interest how long does the camera-moving step take? Around 1 second. You only have to move the phone a tiny bit (maybe 3cm)

Half a sec on my N5 (go slower and it actually complains). It's even shorter with good lightning and with a bit of habit it can come out quite naturally. Frame, snap, slide.

Re: Lens Blur in the new Google Camera app

#244

Post by anoncow » Fri, Apr 18, 2014, 4:06 PM UTC

pollen23 wrote: post #197

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.

Thanks!

Re: Lens Blur in the new Google Camera app

#245

Post by Gracana » Fri, Apr 18, 2014, 4:54 PM UTC

joshuak wrote: post #237

Gracana wrote: post #236

Earlier quoted context omitted.

Thanks for the explanation. I've been working a little bit with a guy doing some computer vision stuff for an industrial system (shingle production line), and I've noticed that a lot of (what seem like) complex problems can be effectively solved with very simple solutions. Is there any simple literature that covers this domain? Like a book of algorithms for computer vision, or something?

Sadly I've found that most sources prefer to be academically rigorous over quickly comprehensible. Of course it's good that people have done the academic work, but it can be tragically comical how obtuse an academic paper can make a simple concept. However, one of the most recommended books on the subject is available online, so you might want to check that out. Computer Vision: Algorithms and Applications by Richard…

Cool, thanks.

re: your first comment... I'm reminded of a lot of the wikipedia pages on mathematical concepts. Sometimes I have to laugh, because they seem so high-level that only someone who already understood the domain could understand them.

Re: Lens Blur in the new Google Camera app

#246

Post by nileshtrivedi » Sat, Apr 19, 2014, 11:14 AM UTC

Houshalter wrote: post #173

nileshtrivedi wrote: post #130

With these algorithms, will it become feasible to make a driverless car that doesn't need a LIDAR and can run with just a few cameras? Currently, the cost of LIDARs are prohibitive to make (or even experiment with) a DIY self-driving car.

Yes. Machine vision has advanced a lot in recent years and it might just be possible. There is at least one startup trying to make self-driving cars with just machine vision. Computing the differences between several cameras can be a judge of distance, but you can also see how much the object moves as the car moves, and get an estimate based on normal machine vision (how big objects like that normally are, objects ne…

Do you happen to remember the name of this startup?

I have been thinking of experimenting with automated driving. Have started reading up on computer vision and found some encouragement from things like these: https://www.youtube.com/watch?v=dcm9NpMNi68

Re: Lens Blur in the new Google Camera app

#247

Post by nileshtrivedi » Sat, Apr 19, 2014, 11:16 AM UTC

rjdagost wrote: post #234

nileshtrivedi wrote: post #130

With these algorithms, will it become feasible to make a driverless car that doesn't need a LIDAR and can run with just a few cameras? Currently, the cost of LIDARs are prohibitive to make (or even experiment with) a DIY self-driving car.

These algorithms can allow you to have a self-driving car with only cameras. But, there would be a lot of problems if you tried to make a camera-only system for consumer vehicle navigation. Vision systems need distinct "features" in images to find and track across frames to allow you to compute distance, speed, etc. If you don't have many features, pure vision approaches won't work. Nighttime operation is a big probl…

Thanks for that explanation. I have been thinking of experimenting with automated driving with cameras and got encouraged by things like these: https://www.youtube.com/watch?v=dcm9NpMNi68 . But yeah, I can understand how ideal conditions are very different from the real world.

Re: Lens Blur in the new Google Camera app

#248

Post by panrafal » Mon, Apr 21, 2014, 12:38 PM UTC

I've created a parallax viewer for lens blur photos. It's an open source web app available at http://depthy.stamina.pl/ . It lets you extract the depthmap, works on chrome with webgl and looks pretty awesome on some photos. There is quite a few things you can do with this kind of images, so feel free to play around with the source code on github https://github.com/panrafal/depthy

Re: Lens Blur in the new Google Camera app

#249

Post by samclearman » Wed, Apr 23, 2014, 4:39 AM UTC

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…

According to the article, and my own experience with google's version, it's good enough for simple portraits. Since most photos, and close to 100% of photos anybody actually cares about, are portraits that makes it a pretty useful feature.