[Q] the tech behind ICS face unlock - Android Q&A, Help & Troubleshooting

I'm only asking this question because I'm bored and curious as to the actual implementation of ICS's face unlock tech.
Face unlock is cool and all, but how does it work? Now, before you type "derp it take a picutre of ur face", read on. So the other night while in the passenger seat of my friend's car, in the dark, I pulled out my phone (a Mytouch 4G Slide) and hit the menu button to wake the screen. Obv I've got face unlock enabled, and obv I wasn't expecting it to work in the dark. But I noticed a very, very faint red (I mean, it downright looked like infrared -- just like the LEDs on a nighttime security camera or the sensor on a Kinect) light coming from the proximity sensor on the front fascia, to the left of where the earpiece grille is. "Weird," I thought, and I hit the padlock icon so I could enter my unlock pattern. The instant I hit the padlock icon and the front-facing camera disengaged, that faint red light turned off as well.
Seriously, try this out yourself. If you've got a device with both a front-facing camera and ICS, give this a shot in a super dark room, or outside at night. Unless you've got a verifiable explanation from Google/OEM documentation, that is.
So... what's going on, and how, exactly, does it work? What's it looking for that it needs infrared? Is it simply for low-light illumination (like an aforementioned nighttime security camera) or is it doing something super awesome with the heat signature from my face (sort of like the tech behind the Kinect)?

...nobody? i'm just really curious if any devs have poked around with the face unlock feature and know how it works.

I'm not sure about the 'infrared' you speak of because I've just been playing around with it on my Galaxy S2 and I didn't notice anything from the proximity sensor. I was under the impression that Face Unlock simply analysed the image for the position of your nose, eyes and mouth and their relative distances to each other in order to work out if it's you or not.
It's certainly not something as crazy as kinect-like sensors or heat detection hahaha, I spent a good few minutes with one of my friends fooling his Nexus's face unlock with a photo of him I had on my phone - I think you'll tend to find pictures where people are smiling maniacally don't tend to work.

Same here on my Asus Transformer. No light emitting sensor. My guess is, the sensor is input only unable to emit anything. The faint red you noticed might as well be a reflection of some kind?
Where are the pictures stored anyway, because I`m worried about privacy issues. Especially in the light (no pun intended) of the latest security flaws in iOs and Android OS regarding stored pics on internal memory. Or is it just me being paradroid?

Well, dang, I wish I had some way of posting a video of the faint, red light. It's one hundred percent absolutely not a reflection... you ever looked at a security camera's IR illuminating LEDs? How it looks super dim and dark red? It looks exactly like that. I know it's somehow related to the face unlock feature because it's only on while the camera is showing my face. As soon as it detects my face, or if I hit the little unlock icon to use the pattern instead, the LED shuts off. I was hoping someone could pull up a Google developer reference that had some explanation.
Maybe I'll borrow someone's cell phone and use it to take a video of it.

i have a one x att and i've noticed the infrared light
but i think its just for the proximity sensor
nothing to do with face unlock
---------- Post added at 04:24 PM ---------- Previous post was at 03:48 PM ----------
i have a one x att and i've noticed the infrared light
but i think its just for the proximity sensor
nothing to do with face unlock

Related

[REQUEST] Modding the LightSensor

Do you like the light Sensor on Nexus?
I didn't like it.
It's a very good feature, but it works strange.
It is slow in dimming and took already not enough light to the display.
Nexusdisplay is dark dark dark...
Does anybody know, how to tweak this sensor?
Or am I the only one who dislike it very much?
I just set my brightness manually. Done deal.
Perfect.
In the Night I'll put my sunglasses on or at a sunny day I take my nexus blind...
Wherefor is the sensor if it don't work proper?
There must be some settings for...
I think the light sensor works great but it would be even better if we can customize it a little bit. Something like scale up the screen brightness for each level of external light.
Or something like auto lock when it is totally dark (you put it into your pocket?).....but that would cause trouble if you want to use your phone in the theater
I think the light sensor is terrible. I have tried everything but it still seems very finicky on when it will work properly. I regularly go from low light to sunny outdoors and having the feature would properly would be awesome, especially since it worked fine on my last 2 phones and they arent even close to being a superphone.
Trying to make it transition smoother is something I've been meaning to try. The settings for this are in the source tree at frameworks/base/core/res/res/values/config.xml (I override this in my passion vendor overlay). You can tweak the values and rebuild framework-res to try it out.
oh cyanogen, You Are GOD!
Where we can find it?
I've searched the whole framework.
ha he meant the source tree for framework provided by google. not in the framework-res inside of the zip of the rom you are using.
two things I noticed about it:
1 It dims and brightens too quick, it should take an average light level over a longer time period
2 Our fluorescent lights in the office at work seem to confuse it, so that could mean that the lens is too focussed and if you hit one of the lights it goes too bright, miss and it goes too dim as you move around and/or the wavelength of the lights confuse it - though this problem may be more bearable if #1 above is fixed.
I gave up using the sensor. I use the power strip. the 3 settings work great for me.
Ssantos6981 said:
I gave up using the sensor. I use the power strip. the 3 settings work great for me.
Click to expand...
Click to collapse
Yea I mean why should it work? We only paid $530 for it ;/
spyz88 said:
Yea I mean why should it work? We only paid $530 for it ;/
Click to expand...
Click to collapse
Yes, these words are soooo true! They're absolut true.
And: It's not HTCs first device with such a sensor. It's not the first android Handset with such an sensor.
I can't understand, why they did such a thing!
@spyz88: I'll pray your words every time if i see this dumb dimming and flickering.
I too have noticed this problem, and have such, turned it off. Disappointing, yeah.
I hope someone can come up with some good idea/settings, to fix this like google should be doing already :/....
Thanks people
spyz88 said:
Yea I mean why should it work? We only paid $530 for it ;/
Click to expand...
Click to collapse
You can pay £30,000 for a car and things still don't work properly.
Nature of the beast I'm afraid.
OK, we can put our heads down in the sand or we can try to make us happier with it.
Does anybody tells google/htc that this is crap?
Probably we can make it on our own.
yeah it doesn't work very well. Maybe sensitivity needs to be lowered somehow
I hate to say this because I always talk crap about the iphone, but the iphone does have a better way to auto dim the screen with the sensor.
I thought I had a problem because from the get go I installed a screen protector that lays over the sensor, but now I see that other people have the same issue.
It is funny because I can have the phone in one place, but if I change the angle the screen will dim or brighten.
the worst thing is , it comes in the way of reading constantly on your phone , and after two to three cycles of dim/bright , you would eventually give up and disable it. disappointing .
but i think the problem is it samples ambient light with long interval , and then average it in a way that is always behind what it should be
This has bothered me as well and I've been looking for an easy way to fix it.
It seems that the light sensor (or its driver?) is to sensitive or inaccurate. The reported LUX value can fluctuate a lot in constant surrounding light. There is also the possibility that one waves a hand in front of the sensor which can produce undesired brightness changes etc.
My idea:
PowerManagerService.java (frameworks/base/services/java/com/android/server) listens for light sensor changes with a SensorEventListener. Either directly or after (config_lightSensorWarmupTime) a method called lightSensorChangedLocked is called with the sensor value as parameter. This method sets the brightness.
Here we can add some low pass filtering to the sensor value before calling lightSensorChangedLocked. Maybe a simple average of the last 5 values or so will suffice? Maybe take time into consideration as well. Say average 5 or all values received in the last 20 seconds or so. There sure are room for improvements of my suggestions.
My message is that the issue is perfectly fixable and PowerManagerService.java is the file to fix it in.

[Q] eye sensor

how do I activate the eye sensor? or is it on automaticly? are there any settings about I can change?
Settings>Display>Smart stay.
Seems not to work so well for some. Almost flawless for me. YMMV.
The eye icon will only appear just before the time the screen would normally go off, this is when it looks for eyes and decides if the screen should be kept on.
I think a lot of people expect to see the icon all the time.
I have the "smart stay" enabled but it does not work for me. I have only had it for a day in in door light, so I don't know if that is the problem. I have verified that the front facing camera works by placing a Skype video call. Also, I have brown eyes.
Why do you say that it doesn't work? What the smart stay does is, after an amount of time it sees if you are look to the screen, if you are it keeps the screen on, if you are not it closes the screen.
Mine works and i also have brown eyes.
I have small eyes and it works for me
It works for me 50% of the time. It depends on the angle you hold the phone and the amount of lighting.
I don't know how it worked in the Samsung commercial that was advertising this feature given how dark the room was.

[Q] The camera doesnt focus in dark rooms or on objects in dark areas....

Hello everyone, I may be missing something but i was playing around with the camera on this great phone and realized that the normal press and hold of the shutter button to have the camera focus in a dark room does not work. If you press and hold the camera takes shots in burst mode. If you press it once the flash lights up dimly but does not focus properly and then flashes full blast but takes a blurry photo. This is very annoying because im used to my samsung s3 and note 2 that would focus by holding the shutter button in a dark room and then release to take a clear focused picture.
Am I missing something? for a camera that is good in low light and have 5 levels of flash intensity it seems to make no sense to not be able to focus in a dark room. whats the point of having a camera with a flash that cant take a picture in the dark or semi dark room right?
let me know if you are having this issue, if you think i'm doing something wrong or maybe if ill just have to deal with it until HTC comes out with an update. if it happens to you we can all call 8664498358 and press 0 and let HTC know this is very annoying I have gotten through to a live person instantly by calling this number to ask why in the world the power saver feature is persistent in the notification drop down....there reason....dummy instructions and to many service returns for "bad batteries"
UPDATE: I have spoke with HTC on a separate issue and mentioned this to the guy i spoke with and he has not had any other feedback on this issue, how ever he advised me to have anyone who is having this issue please contact them, he was not able to duplicate it yet because he in not in a dark room but he said he will try it when he can (Thanks Fred). the more people who report the issue and provide feedback the better chances they can get it resolved, I am having this issue on my wifes phone and my phone. you may need to focus on a far object and then try to focus on a near object in a dark room, like a room with less then low light. In my case it was in a room only lit by an old crt tv (bedroom) how ever he advised me the more feedback the better, they are very interesting in hearing from us and he is very aware of the xda forums as well as other android forums out there.
so no one cares. nice
So much for the community. No one seems to care even though plenty of you guys have looked and all own this phone. Pretty disgraceful.
EDIT: Sorry if I sound rude or condescending, Just surprised no one has commented yet or has said they are having this issue, personally I use my phone for taking photos in less then low light situations often and if this issue cant get resolved its going to really suck. HTC can fix it but needs the feedback to know that its widespread and not just a fluke, although they do know that its happening on my wifes phone and my phone.
I've tried it, and it doesn't auto-focus either. Manually focusing before taking the picture works though.
Zolor23 said:
I've tried it, and it doesn't auto-focus either. Manually focusing before taking the picture works though.
Click to expand...
Click to collapse
Thank you very much for the reply, I have tried to manual focus and it doesnt work for me in very dark situations. sometimes it does and sometimes it doesn't though. I have noticed if I focus on something distant in a low light area and then back on something near in a very dark area it will not focus. Every other camera I have used on a phone has lit up the flash long enough and bright enough to focus and turn the focus indicator green how ever this camera seems to focus on speed and seems to not care about weather the picture is focused, it doesn't turn red or beep or anything it just takes a blurry photo. it takes more blurry photos then clear it seems to me in low light or less then low light conditions.
If you could please contact HTC and let them know I would be very happy and hopefully they get this issue fixed, I have called HTC a few times for other issues. yesterday my lock screen kept saying today was cinco de mayo and for the life of me I couldnt figure out how to turn that off and I also am not happy about the Gallery app showing every single friend photo including horribly low resolution ones not to mention the persistant power saver notification in the drop down thats so stupid! but when I talked to them they mentioned the camera issue and wanted me to explain to them cause they saw the notes based on my phone number and previous calls, they would like all the feedback they can get.
This isn't just a T-Mobile HTC One issue, my international is doing this too.
I'd be interested to know from someone that doesn't have this problem, in a dark room, if you tap on the screen to focus, does the light come on?
All other phones I've had would light the area to focus, as you've said above this just tries to focus in the dark. How can that be right?
I've tried different ROM's and firmware, always tries to focus in the dark. Why on earth would it do this!?!?!
Yeah I noticed that problem too when trying to take a picture of a person in a life like Iron Man costume in a theater Friday night.
Sent from my Nexus 7
lets get this fixed!
Boy I'm glad I'm not the only one. I know we are about fixing stock and nodding and what not but please start a ticket on the issue. HTC has a place on there website for this or you can call them.

Face unlock failing and not working In direct sunlight

It's good to have a ir based face unlock especially it is helpful in dark conditions but it is giving me a hard time In unlocking the device in direct sunlight is anyone facing the same problemconfused:
NEON98 said:
It's good to have a ir based face unlock especially it is helpful in dark conditions but it is giving me a hard time In unlocking the device in direct sunlight is anyone facing the same problemconfused:
Click to expand...
Click to collapse
Having the same issue too. I totally understand why it fails to recognize my face. Maybe it's just too bright for the camera to scan anything so I just use FP unlock when outside. Anyway, another user has raised this concern in Jai Mani's twitter account and said that he will look into it.
NEON98 said:
It's good to have a ir based face unlock especially it is helpful in dark conditions but it is giving me a hard time In unlocking the device in direct sunlight is anyone facing the same problemconfused:
Click to expand...
Click to collapse
Well its not a problem.
Because sun also emits infrared radiation(lots of) , maybe it also interfere with our ir sensor,
For example :-
If your phone's front is directly facing sun and trying to unlock your device vise-vera. That ir sensor also picking up direct waves from sun and as well as incident waves from the face and unable to get proper data. I am definitely sure other phones with IR sensor also face this issue ( tested with galaxy s8+ it also doesn't work and iPhone will face this issue too).
P.S-If anyone find it wrong feel free to correct me and don't try to roast me with your incredible KNOWLEDGE!.
---------- Post added at 09:49 AM ---------- Previous post was at 09:43 AM ----------
chickentuna said:
Having the same issue too. I totally understand why it fails to recognize my face. Maybe it's just too bright for the camera to scan anything so I just use FP unlock when outside. Anyway, another user has raised this concern in Jai Mani's twitter account and said that he will look into it.
Click to expand...
Click to collapse
ir face unlock does not use camera. It use separate IR sensor which only pick up infrared wave(don't get confused with visible light. infrared is out of visible wave spectrum you can't see with naked eyes). Do a experiment hide your camera and try to unlock.
That left sensor is ir sensor and right is camera(which actually picks visible light).

3D Face Unlock: problem, issue, inaccurate

Hey, have this phone from yesterday, europe dual sim version. How is for you the 3d face unlock?
I feel it's often inaccurate and in these cases it it does not unlock the phone.
Also, when i am in a dark room wit a good light behind me it's often inaccurate and, again, in these cases it it does not unlock the phone always.
In fact, if you try to register your face in this last condition you will see the face very very dark and this is a problem obviously for the face unlock.
I remember this last same "dark" problem also with the P20 Pro sensor.
What you think? Any solutions? Maybe in next updates?
Edit 1: https://www.reddit.com/r/Huawei/comments/9rnmpa/mate_20_pro_face_unlock_issues/
Edit 2:
I'm having similar issues here.. It will work perfectly sometimes and then just doesn't
Click to expand...
Click to collapse
UP
https://www.reddit.com/r/Huawei/comments/9rnmpa/mate_20_pro_face_unlock_issues/
Edit 2:
I'm having similar issues here.. It will work perfectly sometimes and then just doesn't
Click to expand...
Click to collapse
just dont register your face in bad lighting conditions where it cannot be registered properly. I dont understand your problem tbh. Face unlock is a combination of the infrared thing and the camera.... if you use your phone while sitting in front of a bright light you cannot expect it to work. its like having wet or dirty fingers and comlpaining fingerprint isnt working.
0alfred0 said:
just dont register your face in bad lighting conditions where it cannot be registered properly. I dont understand your problem tbh. Face unlock is a combination of the infrared thing and the camera.... if you use your phone while sitting in front of a bright light you cannot expect it to work. its like having wet or dirty fingers and comlpaining fingerprint isnt working.
Click to expand...
Click to collapse
Conditions are good.
if you use your phone while sitting in front of a bright light
Click to expand...
Click to collapse
.... behind of a bright light, as written in first post, in fact if i try to register face in this last condition face is almost dark, but in this case the infrared camera should not help anyway?
With my iphone x in the SAME condition the face unlock works ALWAYS instantly, so i can see the difference.
denzel09 said:
Conditions are good.
.... behind of a bright light, as written in first post, in fact if i try to register face in this last condition face is almost dark, but in this case the infrared camera should not help anyway?
With my iphone x in the SAME condition the face unlock works ALWAYS instantly, so i can see the difference.
Click to expand...
Click to collapse
Well if you register your face in good lighting and the unlock does not work in good lighting then there is probably something wrong. You should contact huawei about that.
If you are trying to create a bad lighting condition on purpose and then it doesnt work I am not sure why you do this. There is no point. If you are in everyday live, like in a bar or pub and the lighting is bad you have to expect that face unlock is not going to be the most reliable. Its that simple. Sitting at home and trying to push it to its limits does not benefit you at all.
It is not as secure nor the same technology as face ID so there is no point in comparing them. If FaceID is better you have to accept it. No update can change the hardware.... maybe it will be optimized but it is not going to improve by 100%.
Surely ambient light has nothing to do with the face unlock method used here, as the camera is searching for an IR dot pattern. If anything, I'd expect it to work better in the dark.
0alfred0 said:
Well if you register your face in good lighting and the unlock does not work in good lighting then there is probably something wrong. You should contact huawei about that.
If you are trying to create a bad lighting condition on purpose and then it doesnt work I am not sure why you do this. There is no point. If you are in everyday live, like in a bar or pub and the lighting is bad you have to expect that face unlock is not going to be the most reliable. Its that simple. Sitting at home and trying to push it to its limits does not benefit you at all.
It is not as secure nor the same technology as face ID so there is no point in comparing them. If FaceID is better you have to accept it. No update can change the hardware.... maybe it will be optimized but it is not going to improve by 100%.
Click to expand...
Click to collapse
It works in good light but it's not accurate like FaceID or also other 2D unlock tried until now. It's not accurate, for example, when I'm sitting in an armchair often it wants certain angles to unlock, etc..
I can understand your point about create "bad light condition". Until few days ago i had a One Plus 6 with 2D face unlock, but not only it, and in the same Mate 20 conditions i had no one single problem with angles or light behind me! Maybe it's a bit hard to explain..
David Horn said:
Surely ambient light has nothing to do with the face unlock method used here, as the camera is searching for an IR dot pattern. If anything, I'd expect it to work better in the dark.
Click to expand...
Click to collapse
In fact it is the same thing that I thought! "Better in the dark", but in the evening when there is an artificial light behind me, sitting in an armchair, the unlock starts to have a bit of difficulty. And instead it should be the opposite, it should work better.
In this situation if i try to register my face in fact i see my face really dark cause the light behind me goes exactly on the sensor. Same thing with P20 Pro sensor. Only with Huawei i have seen this "problem". Nor with Samsung, nor with One Plus nor with Pocophone, etc..
It's really strange.
Check the software/EMUI problem thread, see if anyone else is reporting it. Otherwise, it's news to me.
roosta said:
Check the software/EMUI problem thread, see if anyone else is reporting it. Otherwise, it's news to me.
Click to expand...
Click to collapse
I think no one until now. Like no one with P20 Pro. Surely it's not fast like Apple Face ID. In same conditions. Sure about this because i have both with me so...
denzel09 said:
In fact it is the same thing that I thought! "Better in the dark", but in the evening when there is an artificial light behind me, sitting in an armchair, the unlock starts to have a bit of difficulty. And instead it should be the opposite, it should work better.
In this situation if i try to register my face in fact i see my face really dark cause the light behind me goes exactly on the sensor. Same thing with P20 Pro sensor. Only with Huawei i have seen this "problem". Nor with Samsung, nor with One Plus nor with Pocophone, etc..
It's really strange.
Click to expand...
Click to collapse
for comparison. I just tested bad lighting with my mate 10 pro... worked just fine... immediate unlock
i am not sure about the IR thing. it should definately work with no light but i am not sure if it is able to "work against" light. if your light sends out inrared wavelengths it will definately interfere with the IR projector. I am pretty sure though it sends out infrared wavelengths since it gets hot.... heat=infrared light (that how heat cameras work).
denzel09 said:
I think no one until now. Like no one with P20 Pro. Surely it's not fast like Apple Face ID. In same conditions. Sure about this because i have both with me so...
Click to expand...
Click to collapse
Apple were the first to introduce dot-mapping (or whatever they call the technology) to scan all areas, from left to right, of the face. The android versions on phones is more watered down...but it seems Huawei are using their own software of facial mapping which I imagine is designed to work the same as Face ID on Apple...but as there's some bugs with the pre-releases, I'd potentially wait and update the phone in 3-4 weeks to see if it resolve the issue.
RoOSTA
0alfred0 said:
for comparison. I just tested bad lighting with my mate 10 pro... worked just fine... immediate unlock
Click to expand...
Click to collapse
It was perfect in my "condition" with mate 10 pro with light behind me and against the cam. Because it used only the frontal cam! When i tried to register my face with Mate 10 in "my condition" my face was no dark and clearly visible!
This IS a big difference and here there is an "error" starting from P20 Pro to Mate 20 Pro.
0alfred0 said:
i am not sure about the IR thing. it should definately work with no light but i am not sure if it is able to "work against" light. if your light sends out inrared wavelengths it will definately interfere with the IR projector. I am pretty sure though it sends out infrared wavelengths since it gets hot.... heat=infrared light (that how heat cameras work).
Click to expand...
Click to collapse
Perfect point of view. Problem is: with iPhone X the IR "thing" works PERFECT against light, etc..
roosta said:
Apple were the first to introduce dot-mapping (or whatever they call the technology) to scan all areas, from left to right, of the face. The android versions on phones is more watered down...but it seems Huawei are using their own software of facial mapping which I imagine is designed to work the same as Face ID on Apple...but as there's some bugs with the pre-releases, I'd potentially wait and update the phone in 3-4 weeks to see if it resolve the issue.
RoOSTA
Click to expand...
Click to collapse
Yes, completely agree with you.
But i have a little doubt, this last comes from P20 PRO, also this with light behind me and against the sensor shows me my face all "dark" and obviously no update "fixed" this. I remember with this phone in my situation was IMPOSSIBLE use the 2D face unlock.
Idk honestly if an update here can improve this kind of sensor. I hope!
https://forum.xda-developers.com/showpost.php?p=77998095&postcount=83
Facial recognition evidently hates sunlight. If your face is side on to the sun it won't work, you have to either be in shadow or directly in the sun. The fingerprint scanner I'm also finding to be very hit and miss. I have just been out using it to take some photos, lost count of the number of times both methods of unlocking didn't work.
Click to expand...
Click to collapse
Edit...
It seems to me like a directional or sensor spread issue,
If i hold the phone level with my eyes and head straight (straight neck) it works perfectly, if i'm at my desk with it in my hand looking down at it then it doesn't. If i raise my head and phone vertical as its giving me the 'recognising face' message then it unlocks just as i hit vertical/straight neck.
Problem is i look a t**t raising my phone every time i want to unlock it (looks like i'm checking myself out in a vanity mirror!!)
Had the iPhone XS before this and it worked flawlessly head down or not.
Can someone else who is having issues test this theory?
Edit......

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