What are these artifacts in pictures taken on my phone camera?
July 21, 2015 6:59 PM   Subscribe

My wife and I both are using MotoX (2014) phones that are only a couple of months old, and we both keep finding strange artifacts in our photos. For an example, see this picture: Image with artifacts. (look at the faces)

It almost looks like the kind of thing you get when HDR is on and something is moving, but HDR is explicitly turned off on both of our phones (not set on Auto, which is an option, but definitely Off). I've been through all of the other settings, and other than auto-focus, there's nothing else enabled (panorama mode, etc). Searching with a variety of terms has gotten me nowhere - not even a report of someone else with this problem.

We've got two young kids and have already had photos of some special moments ruined. Suggestions for what's going on and how we can fix it would be much appreciated. Thanks!
posted by chrisamiller to Technology (17 answers total)
 
Best answer: My phone (Blu Advance 4.0) does similar stuff with the native camera app. Try using another camera app and see if it clears up.
posted by goblinbox at 7:06 PM on July 21, 2015 [1 favorite]


Are you using digital zoom? I've seen all kinds of weirdness with various digital zoom features.
posted by primethyme at 7:21 PM on July 21, 2015


Response by poster: Followups:
- Nope - no digital zoom.
- The camera app is what came stock on the MotoX. I will look into some other camera apps, but my wife really like some of the features of this one (burst mode, intuitive interface, etc) and my first preference would be to find a fix.
Thanks!
posted by chrisamiller at 7:27 PM on July 21, 2015


Best answer: to me that looks like over-zealous filtering. these cameras have tiny apertures and that's using just natural light, right? the software is really having to fight the noise level.

the simplest fix is to use a flash or turn on some lights. otherwise, maybe there's some "noise filter" settings you can tweak in the software?
posted by andrewcooke at 7:39 PM on July 21, 2015


can you get from the photos the ISO and shutter speed that it used? This review seems to say that there are some problems akin to yours at low light, but their test doesn't have the level of artifacts yours does.
posted by nightwood at 7:41 PM on July 21, 2015


Best answer: That's something that happens in poor light. The camera is receiving only 15 or 25 levels of brightness out of its digitizer, and blowing that up to 256 so that you can see it. The result is serious stair-stepping.

If the phone has a flash, enable it. My phone (not Moto) has three settings: always, never, auto. The last one allows the phone to choose.
posted by Chocolate Pickle at 7:42 PM on July 21, 2015 [3 favorites]


Response by poster: > can you get from the photos the ISO and shutter speed that it used?

That photo's details say:
800 ISO
1/22 shutter speed
2.33985 aperture
4.235 focal length

Does that jive with the low-light hypothesis?
posted by chrisamiller at 8:17 PM on July 21, 2015


Best answer: Does that jive with the low-light hypothesis?

yes. the aperture is wide open, the shutter speed is as low as it wants to go (because you'll start seeing shake) and still it's dark, so it's having to push the "speed" up to 800 which is, if you like, what is giving you the noise.
posted by andrewcooke at 8:35 PM on July 21, 2015


When my camera takes a picture outdoors in daylight, it uses a shutter speed of about 4 milliseconds compared to your 45 milliseconds and a simulated film speed of ISO 100 compared to your ISO 800.

If the shutter is open longer, you get more blurring from hand shake. If the ISO is higher, you get more noise and stairstepping.
posted by Chocolate Pickle at 9:01 PM on July 21, 2015


You probably need more light, but this photo on a review site was at ISO 800 and 1/24 shutter speed and doesn't look bad. But I would suggest experimenting with more light (either daylight or the flash) and see if you still see the stair-stepping.
posted by nightwood at 9:04 PM on July 21, 2015


Nightwood, that picture isn't a good test. If you look at the OP's picture, the worst place is the foreheads, where you're seeing a constant color with a slight brightness change across the range. The picture of the cat with a speckled background doesn't have anything like that; the fur and the wall speckling are already inherently noisy, and so additional noise added by the camera is imperceptible.

The only place in your picture which approaches the OP's problem is in the lower right corner, looking at the radiator -- and it looks terrible in closeup.
posted by Chocolate Pickle at 9:11 PM on July 21, 2015


Best answer: That phone, will well regarded as a Pretty Good Phone, is known for having a hit-or-miss iffy camera which is widely seen as one of its big(but only) weak points.

The hypothesis above about post processing is correct, and a lot of phones have issues with challenging lighting conditions like this. The only ones that don't are the past couple generations of iphone, and really super state of the art android phones like the LG G4 and samsung S6. This stuff is hard when it comes to tiny cameras with tiny optics and tiny sensors(smaller pixels = more noise) that just can't suck up that much light, and only a few companies have cracked it. And mostly very recently.

Full sized digital cameras went through this in the early 2000s, and now many nicer ones can almost literally see in the dark without any distortion like that. In a couple years they'll crack it with phones, but for now the majority of phones display some sort of post processing distortion/noise like this.
posted by emptythought at 2:24 AM on July 22, 2015


Best answer: I agree that this looks like noise reduction gone crazy.

You probably need more light, but this photo on a review site was at ISO 800 and 1/24 shutter speed and doesn't look bad.

It could be that the camera is automatically adjusting the levels after taking the picture, increasing them, which would mean it's effectively a higher ISO.

Chrisamiller, have you seen this kind of effect with outdoor pictures taken during the day?
posted by aubilenon at 3:05 AM on July 22, 2015


Best answer: I also have a Moto X (less than 6 months old) and this has happened to me with a couple of photos. So...it's not just you! The photos it happened to me on were indoor, relatively low-light photos of people from about 3 feet away.
posted by cpatterson at 6:19 AM on July 22, 2015


Best answer: That's usually called "banding" and happens with a subtle gradient is displayed digitally. You'll also see banding when watching streaming content, or even DVDs on television. Sunsets are especially susceptible to this; instead of a nice smooth transition from bright to dark, you see bands of color. (Overly complicated explanation of image compression techniques avoided.)

I know this doesn't help to solve it, but a search for banding moto-x camera might get you some help.
posted by The Deej at 6:41 AM on July 22, 2015


Response by poster: Thanks for the feedback all. I looked back through my photos and couldn't find any from outdoors, for example, with that issue, so the low-light + aggressive noise filter explanation makes sense. We're going to try some other camera apps for a while (hopefully with less aggressive noise reduction algorithms) and see what happens. Thanks again!
posted by chrisamiller at 8:16 AM on July 22, 2015


I have a Moto-X from about Feb. 2014. My experience is that it's not a particularly wonderful camera. A big problem with cameras and kids is shutter delay. Kids go from looking ultra-cute to looking ordinary quicker than most cameras can snap.
posted by SemiSalt at 12:12 PM on July 22, 2015


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