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Low Light and High Dynamic Range photography in the Google Camera App

googleresearch.blogspot.com

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Re: Low Light and High Dynamic Range photography in the Google Camera App

#21

Post by magicalist »

piyush_soni wrote: post #14

The blogspot fails to discuss why Samsung Galaxy S4/S5 HDR results are much better than my Nexus 5's. Also, there are limitations in leaving it on. Besides it being slow, it also has other restrictions like the inability to use Flash while in HDR+ mode. Howsoever good it may be by default, flash is sometimes important not only in dark, but also when facing sunlight while taking the shot.

> The blogspot fails to discuss why Samsung Galaxy S4/S5 HDR results are much better than my Nexus 5's

Well, $300 price difference can buy you a lot.

Now I get it. Comments like this one must be why Google felt pressured into making the next Nexus phone so much more expensive :P

Re: Low Light and High Dynamic Range photography in the Google Camera App

#23

Post by thrownaway2424 »

personZ wrote: post #16
thrownaway2424 wrote: post #9

Meh. The camera software on Android is so bad that a default-setting picture from an iPhone looks as good or better than an HDR picture on Android. People have demonstrated the quality you can get from the sensor on a Nexus 5 if you capture raw and process offline[1]. I realize that these Google[x] researchers are probably not responsible for the mainline camera application, but the organizational details of Android…

What a dismissive bunch of prattle. Meh. This is about algorithms to achieve better results with a given sensor. The Nexus 5, like the various Nexii that came before, has a poor image sensor -- it's a $300 smartphone, and LG wasn't going to put the best in it. HDR+ gives rather decent results in a wide range of settings despite that, and mine has managed a large number of fantastic shots. The Nexus 6, being twice the…

The Nexus 5 has a really excellent Sony camera module with 1.4 micron pixels. It's comparable to bordering on identical to the sensor in the iPhone 5s, which produces far better images.

Re: Low Light and High Dynamic Range photography in the Google Camera App

#24

Post by sp332 »

vilhelm_s wrote: post #19
sp332 wrote: post #5

Earlier quoted context omitted.

No, it takes multiple photos with the same settings and just averages out the noise in the shadows. That wouldn't keep the shadows from lacking detail though. You'd just get a smoother black!

I think it should work for shadows also? Adding together 10 photos taken at 1/100s should give the same amount of light as one photo taken at 1/10s.

But if each photo is just black because it's underexposed, then adding them together only gives you black.

Re: Low Light and High Dynamic Range photography in the Google Camera App

#25

Post by mvgoogler »

sp332 wrote: post #5
bentcorner wrote: post #4

> However, bracketing is not actually necessary; one can use the same exposure time in every shot. By using a short exposure HDR+ avoids blowing out highlights, and by combining enough shots it reduces noise in the shadows. Does this mean they're using ISO bracketing instead of exposure bracketing?

No, it takes multiple photos with the same settings and just averages out the noise in the shadows. That wouldn't keep the shadows from lacking detail though. You'd just get a smoother black!

You can effectively with increase the ISO in the dark areas without increasing the noise by averaging together multiple photos

Re: Low Light and High Dynamic Range photography in the Google Camera App

#26

Post by FreakyT »

It's unfortunate that HDR mode in Google Camera remains unavailable for phones other than the Nexus 5 & 6 -- I have a Moto X, and the app is really only useful for photospheres, since normal photos tend look awful without HDR.

Has Google discussed any technical reason for this restriction? Seems like lots of third party apps support HDR on a wider variety of phones...

Re: Low Light and High Dynamic Range photography in the Google Camera App

#27

Post by rcthompson »

thrownaway2424 wrote: post #9

Meh. The camera software on Android is so bad that a default-setting picture from an iPhone looks as good or better than an HDR picture on Android. People have demonstrated the quality you can get from the sensor on a Nexus 5 if you capture raw and process offline[1]. I realize that these Google[x] researchers are probably not responsible for the mainline camera application, but the organizational details of Android…

How is it fair to compare the default settings, which are presumably optimized for handheld shots, to a half-second exposure from a tripod? Of course a picture with a stable half-second exposure will be far, far better than anything the defaults come up with. But it's effectively complaining that a tripod gives better results than handheld shots.

Re: Low Light and High Dynamic Range photography in the Google Camera App

#28

Post by crishoj »

seunosewa wrote: post #13
thrownaway2424 wrote: post #9

Meh. The camera software on Android is so bad that a default-setting picture from an iPhone looks as good or better than an HDR picture on Android. People have demonstrated the quality you can get from the sensor on a Nexus 5 if you capture raw and process offline[1]. I realize that these Google[x] researchers are probably not responsible for the mainline camera application, but the organizational details of Android…

I guess HDR+ is supposed to close that gap. Recent iPhones do something very similar all the time.

HDR is provided as an additional, alternative photo by the iOS camera app, if the scene is deemed to benefit from HDR processing.

Re: Low Light and High Dynamic Range photography in the Google Camera App

#29

Post by personZ »

thrownaway2424 wrote: post #23
personZ wrote: post #16

Earlier quoted context omitted.

What a dismissive bunch of prattle. Meh. This is about algorithms to achieve better results with a given sensor. The Nexus 5, like the various Nexii that came before, has a poor image sensor -- it's a $300 smartphone, and LG wasn't going to put the best in it. HDR+ gives rather decent results in a wide range of settings despite that, and mine has managed a large number of fantastic shots. The Nexus 6, being twice the…

The Nexus 5 has a really excellent Sony camera module with 1.4 micron pixels. It's comparable to bordering on identical to the sensor in the iPhone 5s, which produces far better images.

They are entirely different sensors, and share nothing at all in common. To start, the Nexus 5 has a 1/3.2" sensor, while the 5s has a 1/3.0" sensor (making evident from the start that in no universe are they "bordering on identical"). The iPhone has a f2.2 lens assembly. The Nexus has a f2.5 lens assembly. Empirically in both of those cases the iPhone has the superior option, not even getting into the specifics of tiering and segmentation.

The Nexus 5 has a camera sensor equivalent with the iPhone 5, on paper, but is handily and easily beaten by the 5s, and it shows.

Re: Low Light and High Dynamic Range photography in the Google Camera App

#30

Post by rcthompson »

sp332 wrote: post #5
bentcorner wrote: post #4

> However, bracketing is not actually necessary; one can use the same exposure time in every shot. By using a short exposure HDR+ avoids blowing out highlights, and by combining enough shots it reduces noise in the shadows. Does this mean they're using ISO bracketing instead of exposure bracketing?

No, it takes multiple photos with the same settings and just averages out the noise in the shadows. That wouldn't keep the shadows from lacking detail though. You'd just get a smoother black!

You're correct that it's taking multiple photos with the same settings, but the trick is that it can choose different settings than it would have for a single photo. So instead of a single medium-ISO shot that loses all shadow detail but minimizes noise, it could take multiple high-ISO shots to capture the shadow detail and then average them to minimize noise.

So if you think of your dynamic range as being limited by the noise floor and the overexposure ceiling, this technique lowers the noise floor while keeping the ceiling right where it is, giving you a better effective dynamic range. ISO bracketing extends both the floor and ceiling by a much larger margin, of course, but its has issues that complicate its use in automated HDR shots, as described in the article.

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