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[APP] Galactic Night: nightmode for rooted Galaxy-series devices

OP arpruss

9th August 2012, 07:04 PM   |  #1  
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Edited: Now in Google Play.

Galactic Night, now in the 0.99rc2 version, provides red, green or sepia (or blue if you really want!) night modes for rooted OLED Galaxy S2, S3 and Note devices (not tested on Galaxy 7.7 but might work). You can invert the screen colors (so you can browse in white on black, or green on black, or red on black). There is also an Outdoor mode which washes out the colors but might improve legibility outdoors.

I like reading ebooks in green on black when in the dark.

As of my present knowledge, various pre-release versions of this have been tested on:
Galaxy S2: Gingerbread and ICS
Galaxy S3: ICS
Galaxy Note: JB
It should work on ICS on the Note as well, but I don't have any reports. GN works by adjusting the mDNIe profile. If you have some Samsung device I haven't heard of which has a Screen Mode setting in the Display settings that includes Dynamic/Normal/Movie options (and maybe others), there is a chance that this will work for you.

My benchmarking has not shown any statistically significant impact on graphics rendering speed.

Use at your own risk. If a mode screws up the screen display, you should be able to get back to normal by pressing "Standard" or rebooting, but I offer no guarantees.

Several users have asked for customizable settings. These could easily be provided, and could adjust for screen color tint and so on, but I haven't implemented them yet. I might in fact leave those for a Pro version.

You might be curious how the nightmode differs from that in ChainFire3D. ChainFire3D's nightmode works by dropping channels. E.g., in red mode, it simply drops the green and blue channels. This means that things on screen that were in pure green or pure blue get changed to black. Galactic Night uses a different color adjustment which is equivalent to this algorithm: first convert the RGB color on the screen to a luminosity, and then use the luminosity to set the night mode color. Thus, in red mode, pure white will go to maximum brightness red, but red, green and blue will go to different shades of red. This preserves a lot of the legibility.

There is also an odd "No blue" mode which converts RGB images to RG images, so white goes to yellow, blue goes to a dark yellow, etc. I've heard that blue light makes it harder to fall asleep, so it might help with falling asleep if you switch your phone to "No blue" mode for an hour before going to bed, if you can tolerate how ugly it looks.

Here is a photo of GN in action. It is not possible to take a screenshot of it in action, because the color changing is done between framebuffer and display, so the framebuffer that the screenshot accesses will not reflect the color changes.

I've already posted about this in a few device-specific forums, but now it's ready for wider dissemination.

Last edited by arpruss; 16th August 2012 at 02:34 AM.
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10th August 2012, 09:27 PM   |  #2  
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Let me add that the green mode should nicely help save batteries. Using just the green subpixels should use about 1/3 of the power, and yet maintain a lot of visibility because our eyes are very sensitive to green light.
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11th August 2012, 09:57 PM   |  #3  
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Users report that on ICS there is a 1/2 second flash of the regular colors when you turn the screen on. In 0.99rc3 I implemented a red-and-black logo overlay that should cover up most of that flash (it doesn't cover up the status bar, alas). I can imagine it would be really annoying to be in the dark and get a flash of white light even for half a second.

Reports would be appreciated.

If the logo annoys, you can turn it off in GN's settings.
12th August 2012, 03:36 AM   |  #4  
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Great app. Works well. Having no trouble with the logo for screen on.

I'm not sure how difficult this would be to implement, but it would be useful to have a tasker plugin so that red mode could be activated when you run certain apps or at specific times of day.

Keep up the good work.

Sent from my GT-I9100 using xda app-developers app
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12th August 2012, 04:24 PM   |  #5  
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Quote:
Originally Posted by arpruss

Let me add that the green mode should nicely help save batteries. Using just the green subpixels should use about 1/3 of the power, and yet maintain a lot of visibility because our eyes are very sensitive to green light.

The description for the app "Filter your screen" specifically says that you should avoid monochromatic filters which are not grayscale, in order to avoid some kind of burn-in, and thus a permanent tint on our (AM)OLED screens. Do you know anything about this?

I'd love to use the red or green filter, but I'm not sure I dare to, at least not for any significant amount of time.
12th August 2012, 04:46 PM   |  #6  
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Quote:
Originally Posted by ugumba

The description for the app "Filter your screen" specifically says that you should avoid monochromatic filters which are not grayscale, in order to avoid some kind of burn-in, and thus a permanent tint on our (AM)OLED screens. Do you know anything about this?

I'd love to use the red or green filter, but I'm not sure I dare to, at least not for any significant amount of time.

I must say I haven't thought of that. That's an issue. But it's no more an issue than if you heavily use an app that uses a single color. Or if you heavily use an app that has a single bright display element in one place.

It's going to be more an issue if your background is all white, and then it turns, say, all green, and then the green subpixels burn out faster than the red and blue. But if you use green+invert with that, then you will have a lot fewer green pixels, most of them being black.

Moreover, I assume the issue will be mitigated to some degree if you set low screen intensity, and most of us will do that at night. Just use my ScreenDim app at night and use a combination of the two sliders to set a very low brightness. (Or use ScreenFilter or something else like that.) However, this does mean that we probably don't want to use a monochromatic screen all the time during the day, unless, well, we want to use it all the time and hence the tint will irrelevant.

If the burnin does a uniform tint across the screen (which may not be the case), then we can eventually correct for it with a custom color profile.

Or you can alternate between red/green/blue modes on a regular basis.
12th August 2012, 04:47 PM   |  #7  
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Quote:
Originally Posted by b631nz

Great app. Works well. Having no trouble with the logo for screen on.

I'm not sure how difficult this would be to implement, but it would be useful to have a tasker plugin so that red mode could be activated when you run certain apps or at specific times of day.

It would be easy to add Tasker support at the same time as I add launcher shortcuts.
13th August 2012, 01:39 AM   |  #8  
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I just posted 0.99rc4. New mode: Mono sepia. The standard sepia mode just changes white to sepia. Mono sepia changes white to sepia, and makes everything monochrome.

I've discovered a great use for the mono sepia and BW modes. The Kindle app screws up subpixel rendering (just as it is screwed up on the Kindle Fire), resulting in colored shadows around letters in some orientations (portrait on my S2, but this may differ). All the single-tone modes (sepia, BW, green, red and blue) will change the subpixel antialiasing to grayscale antialiasing, which to my eyes significantly improves appearance. (Subpixel antialiasing is wonderful--but mainly when done right.)
13th August 2012, 04:14 PM   |  #9  
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I just uploaded 1.00.
14th August 2012, 05:08 AM   |  #10  
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It's now in Google Play. Free, no ads (other than a link to my other apps). I am planning a pro version that will allow (a) automatic activation on boot (with some sort of safety mechanism in case you put in some bad settings like black on black--maybe if you boot with the device upside down or something like that it won't start on boot?); (b) custom modes.
Last edited by arpruss; 14th August 2012 at 05:10 AM.

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