[Q] Android DPI - Android Q&A, Help & Troubleshooting

Can someone please explain how the android DPI system works?
If i reduce my dpi on my Gnex, from 320 to 250, everything gets smaller; it gets denser (as there is more in a smaller space), however the name (dots per inch) would suggest that a higher figure would result in a more dense screen.

maxib123 said:
Can someone please explain how the android DPI system works?
If i reduce my dpi on my Gnex, from 320 to 250, everything gets smaller; it gets denser (as there is more in a smaller space), however the name (dots per inch) would suggest that a higher figure would result in a more dense screen.
Click to expand...
Click to collapse
http://developer.android.com/guide/practices/screens_support.html
There is plenty to read... but you might just take a look at figure 4. which explains sizes of xhdpi, hdpi, mdpi and ldpi drawables.
It's basicly hidger dpi = higher res drawable = takes more space on your screen.

Related

is it possible to change resolution on my viewsonic tablet?

Hi All,
I currently own a viewsonic vpad 10s tablet. It's currently on 1024x600.. is it possible to have a software hack or other to change the resolution to 1280x like the xoom?
The short answer is no.
The longer answer is...kind of.
https://market.android.com/details?id=com.beansoft.lcd_density_changer&feature=search_result
BK553 said:
The longer answer is...kind of.
https://market.android.com/details?id=com.beansoft.lcd_density_changer&feature=search_result
Click to expand...
Click to collapse
OK, and now the even longer answer.
There is no way to increase the resolution to 1280 x 800. Our display is an AU OPTRONICS B101AW06. Look it up on the net & you'll find max resolution is 1024 x 600. What BK553 is speaking about is a change in text DPI. You can see this in Windows where you can change the DPI. Manufacturers normally set the DPI to give the user the best readability but not necessarily the highest DPI. If you change the DPI, text & icons will become smaller (or larger depending on if you increase or decrease the DPI). To see what effect LCDDensity Changer may have, see the attached picture. Icons are smaller & text is smaller, giving the illusion of higher resolution. Notice how the backbround is the same while the text & icons are smaller.
Again, you can not change the resolution...videos, pictures etc will always displayed at a max resolution of 1024 x 600.
By the way, check this post http://forum.xda-developers.com/showthread.php?t=864338&highlight=lcd and you will see that atleast in Dec 2010 there used to be a field in build.prop that you could change to change the DPI. I looked for it in mine (I'm running Calkulin+Clemsyn Combo v6) and that field no longer appears.
hatorihanzo said:
Hi All,
I currently own a viewsonic vpad 10s tablet. It's currently on 1024x600.. is it possible to have a software hack or other to change the resolution to 1280x like the xoom?
Click to expand...
Click to collapse
I use blade and spare parts to tweak the dpi. don't think you can get up to 1280 with any software though.

Rooted Nook Tablet Options

Indirect deserves a salute for rooting the NT
http://forum.xda-developers.com/showthread.php?t=1354487
Still running a Nook Color with a dpi of 240 in build.prop, I would very much
get any reports on the following
1. Can the same be done on the NT without too many side affects?
2. Has anyone installed skype and tested the built in Mic?
How about a response as to a rooted Nook Tablet with a higher (240) dpi setting?
speaking completely out of curiosity, how can you display a higher dpi onscreen (if I'm understanding what you're asking), if the display is only capable of 169 dpi?
maybe I'm oversimplifying the question and am not understanding you.
---------- Post added at 01:33 PM ---------- Previous post was at 01:31 PM ----------
after doing some searching, are you referring to actual font size?
Android allows different dp settings independent of the hardware dpi for UI design. Details in below link,
http://developer.android.com/guide/practices/screens_support.html
Density-independent pixel (dp)
A virtual pixel unit that you should use when defining UI layout, to express layout dimensions or position in a density-independent way.
The density-independent pixel is equivalent to one physical pixel on a 160 dpi screen, which is the baseline density assumed by the system for a "medium" density screen. At runtime, the system transparently handles any scaling of the dp units, as necessary, based on the actual density of the screen in use. The conversion of dp units to screen pixels is simple: px = dp * (dpi / 160). For example, on a 240 dpi screen, 1 dp equals 1.5 physical pixels. You should always use dp units when defining your application's UI, to ensure proper display of your UI on screens with different densities.
e.mote said:
Android allows different dp settings independent of the hardware dpi for UI design. Details in below link,
The density-independent pixel is equivalent to one physical pixel on a 160 dpi screen, which is the baseline density assumed by the system for a "medium" density screen. At runtime, the system transparently handles any scaling of the dp units, as necessary, based on the actual density of the screen in use.
Click to expand...
Click to collapse
I understand the advantage to a developer laying out UI that needs to run on different display resolutions, but I don't see an advantage for an end-user. Why would you set your dpi to 240 if you can only display 169 dpi on the device? Won't the tablet simply downsize bit-mapped images when they're actually displayed?
Honest question--I'm probably not understanding something here--and I'm certainly not trying to rile anyone. Thanks!
Per above equation, setting your device's dpi setting to 240 would allow the app to be 150% in size. This aids in legibility, at cost of more screen space.
If you have an NC, you can see this firsthand by adjusting abovesaid dpi setting in build.prop up or down.
e.mote said:
Per above equation, setting your device's dpi setting to 240 would allow the app to be 150% in size. This aids in legibility, at cost of more screen space.
Click to expand...
Click to collapse
Ah, cool. Thanks for the info!
All I wanted to know was if the build.prop can be edited on a rooted NT as I have done on the NC.
Also, I will try once more. Did anyone use the Microphone with skype or some other chat app?

Cyanogenmod High screen resolution

I tried to raise the dpi on my mediapad while running cyanogemod by after_silence but if i enter anything above 213 it removes the home and back buttons and changes to the phone style notification bar. Any Ideas? His Rom is great, Its every thing i want except I want to use my 1280x800 screen as 1280x800. I would post this question in his devlopment thread but xda wont allow my account to do this since i dont have enough posts.
You need to lower the dpi to simulate a larger screen dpi.
Basically if the resolution is equal, smaller screen would have bigger dpi than bigger screen.
Android still use the full resolution regardless of the dpi. The dpi is an indicator of how big your screen is and it will choose the appropriate icon, font, etc based on that. You don't loose sharpness just because the font look bigger.
As the previous poster said - Android will use the full screen resolution no matter what.
When you raise the DPI, you are telling the OS that there are more dots per inch. The number of dots on the screen is fixed, so raising the DPI is telling the OS the screen has those dots squeezed into a smaller space.
At the default DPI of about 213, you are telling the OS that your 1280 x 800 screen is 7 inches diagonal (small tablet). Note that in Jellybean and higher, a 7" tablet will trigger the "small tablet" interface that looks like a Galaxy Nexus phone layout but still has tablet elements.
On the MediaPad stock ICS ROMs, the "high resolution" mode reports a DPI of 160, which tells the OS that your 1280 x 800 screen is about 9.3" (larger tablet).
If you raise the DPI even higher, let's say to 300, then you are telling the OS your 1280 x 800 screen is 5" diagonal (very small tablet / very large phone, like the Galaxy Note). In ICS this will pop you into the phone interface.
The OS uses this information to scale fonts and user elements. So if an app decides it wants to output text on the screen that is 0.5 inches tall:
- At 213 DPI the text will be 107 pixels tall
- At 160 DPI the text will be 80 pixels tall
- At 300 DPI the text will be 150 pixels tall.
Mainscreenturnon said:
I tried to raise the dpi on my mediapad while running cyanogemod by after_silence but if i enter anything above 213 it removes the home and back buttons and changes to the phone style notification bar. Any Ideas? His Rom is great, Its every thing i want except I want to use my 1280x800 screen as 1280x800. I would post this question in his devlopment thread but xda wont allow my account to do this since i dont have enough posts.
Click to expand...
Click to collapse
Hello,
just edit your build.prop (/system/build.prop) with appropriate rights (e. g. root explorer):
change
Code:
ro.sf.lcd_density=213
to
Code:
#ro.sf.lcd_density=213
Best regards,
Michael

Change Dpi

Hello
Can i change dpi stock 240. Someone have tested?
kvadde said:
Hello
Can i change dpi stock 240. Someone have tested?
Click to expand...
Click to collapse
A solid-state screen's DPI is a physical attribute, you cannot change it.
I believe OP is referring to the soft DPI settings in build.prop. You must root, then edit the ro.sf.lcd_density setting in build.prop. It's already 240 on CM, not sure about stock though.
Cat McGowan said:
A solid-state screen's DPI is a physical attribute, you cannot change it.
Click to expand...
Click to collapse
You are talking about PPI, not DPI
Stock DPI is also 240.
But why would you want to change that??
If some app is not displaying to your satisfaction, it's better not to modify build.prop, because it could lead to unexpected weird behaviors.
Better is to use the "Xposed Framework" with the module "App Settings"; there you can specify individual DPI settings for each app. The safer and more flexible solution! I use it without problems on all my devices.
Felimenta97 said:
You are talking about PPI, not DPI
Click to expand...
Click to collapse
You have it backwards.
kvadde said:
Hello
Can i change dpi stock 240. Someone have tested?
Click to expand...
Click to collapse
As you didn't specify whether you want this on stock firmware or an AOSP ROM, I'd suggest to try the PACman port to the XTZ, as it includes per-app DPI modifier. It's currently in nightlies and no fully stable release as of yet, but it's worth to try if you really need that feature.
DPI = Dots Per Inch
PPI = Pixels Per Inch
The reason we've started to use PPI instead of DPI is because of PenTile, since that technology yields more pixels than dots per inch (dots are shared between adjacent pixels). Both are properties of the hardware but by telling Android you have a different DPI you can scale the UI. This procedure will make graphical elements that makes use of their physical size on the display (rulers, printing tools, etc.) show up at incorrect sizes.
For example, if you have a virtual measurement tape, you'll need to multiply all values with the original DPI divided by the new DPI. So if you choose to change your tablets DPI to 120, making every UI element scale to half of the original size, you'd need to multiply every value by 240/120=2 for it to match up with the real world.
I hope this clears things up.
Shanliang- said:
As you didn't specify whether you want this on stock firmware or an AOSP ROM, I'd suggest to try the PACman port to the XTZ, as it includes per-app DPI modifier. It's currently in nightlies and no fully stable release as of yet, but it's worth to try if you really need that feature.
Click to expand...
Click to collapse
As I already said: No need to change firmware. Just install Xposed framework with App Settings module on rooted device, and you can freely modify DPI per app.

[Q] Decrease Resolution for Gaming?

Hello Tablet Z community,
This is my first post in this devices forums since getting mine last week. It's a great device, love it, etc.
I've never owned an Android device with a screen resolution this high so I've yet to encounter this problem - some of my games (specifically the emulator PPSSPP) have relatively low framerates (compared to my less powerful Samsung P6810 @ 800x1280). I know with computers in particular it's trivially easy to change resolutions in games/the OS, especially to increase FPS but I've never seen a method to do this on Android and Google searches turn up people mentioning device resolution without changing them.
Does anyone know if it's possible to, ideally, force a different resolution for a particular application? A less than ideal solution would be a system wide change but I would be willing to endure temporarily to increase FPS.
Any advice and suggestions would be greatly appreciated
I would be interested to know about this, iv just loaded ppsspp however havent been able to play any of the playable games listed, I did see a few videos of the xperia z playing well, however that has the same resolution and specs.
juzza87 said:
Does anyone know if it's possible to, ideally, force a different resolution for a particular application? A less than ideal solution would be a system wide change
Any advice and suggestions would be greatly appreciated
Click to expand...
Click to collapse
That was recently discussed in this thread: LCD Density Changes and Results (With Pics)
Cat McGowan said:
That was recently discussed in this thread: LCD Density Changes and Results (With Pics)
Click to expand...
Click to collapse
This is very different, setting the DPI to a non-stock value just resizes the userspace, the resolution is fixed and unchangeable as the OP is thinking. Compared to a Windows PC where you can change the resolution, in Android you only have the ability to change the dpi, which states how large the pixel-to-screen size is. A smaller number indicates a smaller pixel-to-screen size, meaning the information shown on screen is sized for a laeger screen (making it smaller, since the screen is a fixed size). And a larger number has the reverse effect. Android UI guidelines set the optimal dpi for resolution vs. screen size, to mainain a similar experience across devices (similarly sized icons and fonts, etc). Again, this has nothing to do with adjusting the physical resolution of the device, which (to my knowledge) is not possible in Android.
daveid said:
This is very different, setting the DPI to a non-stock value just resizes the userspace, the resolution is fixed and unchangeable as the OP is thinking. Compared to a Windows PC where you can change the resolution, in Android you only have the ability to change the dpi, which states how large the pixel-to-screen size is. A smaller number indicates a smaller pixel-to-screen size, meaning the information shown on screen is sized for a laeger screen (making it smaller, since the screen is a fixed size). And a larger number has the reverse effect. Android UI guidelines set the optimal dpi for resolution vs. screen size, to mainain a similar experience across devices (similarly sized icons and fonts, etc). Again, this has nothing to do with adjusting the physical resolution of the device, which (to my knowledge) is not possible in Android.
Click to expand...
Click to collapse
Heh. Thanks for the schooling, but it was unnecessary, I didn't just fall off a turnip truck.
Thanks for the replies guys, at least now I know for sure..

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