Scaling Images for mdpi - android

I am working on scaling images for my app to make them look great for every screen. I think I follow the different scales for mdpi, hdpi, xhdpi, xxhdpi, etc. The trouble I am having is that the smaller mdpi images are called for the 10.1" tablet making them appear far too small for the large screen size.
For example, I have a play button with the following sizes:
MDPI: 200px x 200px
HDPI: 300px x 300px
XHDPI: 400px x 400px
XXHDPI: 600px x 600px
And the 200px play button is being called to the 10" tablet.
What am I doing wrong? Thanks!

for tablet, the images has taken from drawable-xlarge folder.
The tablet has mdpi. if the image is not in xlarge folder, its get from mdpi folder.
So use xlarge folder.
http://developer.android.com/guide/practices/screens_support.html

Related

Need advice for Android multiple resolution design

For example, I'd like to show an image in screen. Here are the size and dpi:
LDPI - 0.75x 75x75 120 dpi
MDPI - Original size 100x100 160 dpi
HDPI - 1.5x 150x150 240 dpi
XHDPI - 2.0x 200x200 320 dpi
XXHDPI - 3x 300x300 480 dpi
XXXHDPI - 4.0x 400x400 640 dpi
But the display for two devices is not what I want.
The first device is 480x800, 240 dpi. The second device is 800x1280, 213 dpi.The bigger screen has lower dpi. I need some advices on how to handle this case? Thanks
What I see is that your first device is a mobile while the second is a tablet. So you can provide alternate layout files for mobile's and tablets. See supporting multiple screens for more information. For this case for mobile you can use layout-sw720dp folder and for the bigger tablet screen. As for the images your current settings above will work great.

Understanding dpi and the drawable folders

Yesterday I already asked a question about this here. After that I saw this on the official android developer page:
So you can have a 1024x600px screen device with ldpi and a screen with the same resolution with mdpi.
Furthermore you can have a 600x1024px screen device with mdpi and a screen with the same resolution with hdpi.
I have an image, that takes 20 % of the screen's height and width on every device.
I want to make 5 versions of that image (with different resolution) for each drawable folder.
In my past thread I got this answer:
ldpi: 0.75
mdpi: 1.0
hdpi: 1.5
xhdpi: 2.0
xxhdpi: 3.0
xxxhdpi: 4.0
These are the scale factors.
So if my image has a resolution of 50 x 100 px in mdpi it is supposed to have a resolution of 75 x 150 px in hdpi.
I understand that.
The question now is, how am I supposed to know what resolution my image should have in the mdpi folder, if the resolutions for mdpi are totally different (as you can see in the image above -> from 320x480 to 1280x768).
Thanks !
The drawables should be created at a resolution that makes them the right physical size when displayed on the screen. If you have an icon that is supposed to be 1/2 inch by 1/2 inch on an MDPI screen, then the image should be 80px by 80px. This size should be irregardless of the physical dimensions of the screen; the same drawable on a 1280x768 MDPI tablet is supposed to be 1/2 inch by 1/2inch.
If the icon in question should be larger on the tablet for some reason, then you would need to introduce the drawable-swXYZdp-mdpi folder that Der Golem mentioned above. In this folder, you would be able to create a version of the icon that had a larger physical size (say 3/4 inch) that will be loaded on the tablet.

Samsung Note 1 is Loading Resources From Xhdpi Folder

I am having this issue where I have HDPI and XHDPI folders in my eclipse project both have different images resolutions, both Images in the different folders are exactly the same but they differ in size.
So I lunched my app on Samsung Galaxy Note 1 which have 800 x 1280 pixels, 5.3 inches (~285 ppi pixel density) display, but it's loading drawables from the XHDPI folder.
I have tested that by modifying one image in HDPI folder and keep it as it is in the XHDPI folder, the result was note 1 is loading from the XHDPI folder, am I missing something here, it suppose to load images from the HDPI folder because it's screen density is smaller than 320 DPI.
You can check what density your device is set to with
Log.v(TAG, "density=" + getResources().getDisplayMetrics().densityDpi);
am I missing something here, it suppose to load images from the HDPI folder because it's screen density is smaller than 320 DPI
The maker of the device chooses which density bucket to use. Since ~285 is closer to 320 than 240, it is not surprising to me that Samsung chose -xhdpi. Others have reported that it indeed is an -xhdpi device.
If you are finding that -xhdpi resources result in slightly too large of images in certain places, you may need to control that in those places (e.g., set the ImageView size to the size that you want and set android:scaleType to be how you want the image to be adjusted).
it suppose to load images from the HDPI folder because it's screen density is smaller than 320 DPI.
why that?
HDPI is 240 ppi
XHDPI is 320 ppi
Note 1 has a 285 which is closer to XHDPI (|285-320|=35) than to HDPI (|285-240|=45)
On Android developer website, it says,
"hdpi Resources for high-density (hdpi) screens (~240dpi).
xhdpi Resources for extra high-density (xhdpi) screens (~320dpi)."
Any device which has a density higher than 240dpi should load layouts and images from xhdpi folder.
Thus, your app on galaxy note which has 285dpi loads images from xhdpi folder.

android: Galaxy Note 2 : for which pixel layout images/icon should be prepared?

I am developing an app which must support Samsung Galaxy Note - 2.
Now note-2's pixel resolution is 1,280 x 720. Reference Wikipedia.
While developing an app, I found that it was picking images from res/drawable-hdpi.
So for what resolution layout I should prepare the images ? Or do need to make separate resource folder ?
Resources are picked based on DPI a quick reference for what DPI each device uses can be found here:
http://blog.blundell-apps.com/list-of-android-devices-with-pixel-density-buckets/
For image scaling, the images should roughly be sized like so:
if an image is to use 100 dp then the actual images sizes will be:
ldpi: 75px
mdpi: 100px
hdpi: 150px
xhdpi: 200px
if you want to use 100 px on your NOTE 2 then the image sizes will be
ldpi: 50px
mdpi: 66.67px
hdpi: 100px
xhdpi: 133.33px
you can use the following site do do quick calculations:
http://labs.skinkers.com/content/android_dp_px_calculator/
Prepare images for hdpi resolution -- 480x800 hdpi.
Galaxy Note 2 is normal size, xhdpi density and long. You can prepare layout or drawable for xhdpi. For details, please check this post Galaxy Note 2 screen specifications. If you don't have xhdpi resource, android will try to find resource in hdpi.
The Galaxy Note uses hdpi which is a pixel density of 240dpi
Android Device Resolutions

Android: Background Image Size (in Pixel) which Support All Devices

I am creating an Application which will run on all Android Devices. I want to create xhdpi Graphics for My App. My App is full screen. I am confused in Creating graphics. can any one tell me the best sizes of my background image in pixels.
For Example:
xhdpi: 720x1280 px
hdpi: 480x800 px
mdpi: 320x480 px
ldpi: 240x320 px
Suggest me the best sizes which will appear on all devices good. Because my graphics are the core of my app.
I want that every device get the best image which it want. Android will be not involved in compressing or expanding of image.
The following are the best dimensions for the app to run in all devices. For understanding multiple supporting screens you have to read
http://developer.android.com/guide/practices/screens_support.html
xxxhdpi: 1280x1920 px
xxhdpi: 960x1600 px
xhdpi: 640x960 px
hdpi: 480x800 px
mdpi: 320x480 px
ldpi: 240x320 px
Android Devices Matrices
ldpi mdpi hdpi xhdpi xxhdpi xxxhdpi
Launcher And Home 36*36 48*48 72*72 96*96 144*144 192*192
Toolbar And Tab 24*24 32*32 48*48 64*64 96*96 128*128
Notification 18*18 24*24 36*36 48*48 72*72 96*96
Background 240*320 320*480 480*800 768*1280 1080 *1920 1440*2560
(For good approach minus Toolbar Size From total height of Background Screen and then Design Graphics of Screens )
For More Help (This link includes tablets also):
https://design.google.com/devices/
Android Native Icons (Recommended) You can change color of these icons programmatically.
https://design.google.com/icons/
Check this. This image will show for all icon size for different screen sizes
I looked around the internet for correct dimensions for these densities for square images, but couldn't find anything reliable.
If it's any consolation, referring to Veerababu Medisetti's answer I used these dimensions for SQUARES :)
xxxhdpi: 1280x1280 px
xxhdpi: 960x960 px
xhdpi: 640x640 px
hdpi: 480x480 px
mdpi: 320x320 px
ldpi: 240x240 px
GIMP tool is exactly what you need to create the images for different pixel resolution devices.
Follow these steps:
Open the existing image in GIMP tool.
Go to "Image" menu, and select "Scale Image..."
Use below pixel dimension that you need:
xxxhdpi: 1280x1920 px
xxhdpi: 960x1600 px
xhdpi: 640x960 px
hdpi: 480x800 px
mdpi: 320x480 px
ldpi: 240x320 px
Then "Export" the image from "File" menu.
My understanding is that if you use a View object (as supposed to eg. android:windowBackground) Android will automatically scale your image to the correct size. The problem is that too much scaling can result in artifacts (both during up and down scaling) and blurring. Due to various resolutions and aspects ratios on the market, it's impossible to create "perfect" fits for every screen, but you can do your best to make sure only a little bit of scaling has to be done, and thus mitigate the unwanted side effects. So what I would do is:
Keep to the 3:4:6:8:12:16 scaling ratio between the six generalized densities (ldpi, mdpi, hdpi, etc).
You should not include xxxhdpi elements for your UI elements, this resolution is meant for upscaling launcher icons only (so mipmap folder only) ... You should not use the xxxhdpi qualifier for UI elements other than the launcher icon. ... although eg. on the Samsung edge 7 calling getDisplayMetrics().density returns 4 (xxxhdpi), so perhaps this info is outdated.
Then look at the new phone models on the market, and find the representative ones. Assumming the new google pixel is a good representation of an android phone: It has a 1080 x 1920 resolution at 441 dpi, and a screen size of 4.4 x 2.5 inches. Then from the the android developer docs:
ldpi (low) ~120dpi
mdpi (medium) ~160dpi
hdpi (high) ~240dpi
xhdpi (extra-high) ~320dpi
xxhdpi (extra-extra-high) ~480dpi
xxxhdpi (extra-extra-extra-high) ~640dpi
This corresponds to an xxhdpi screen. From here I could scale these 1080 x 1920 down by the (3:4:6:8:12) ratios above.
I could also acknowledge that downsampling is generally an easy way to scale and thus I might want slightly oversized bitmaps bundled in my apk (Note: higher memory consumption). Once more assuming that the width and height of the pixel screen is represetative, I would scale up the 1080x1920 by a factor of 480/441, leaving my maximum resolution background image at approx. 1200x2100, which should then be scaled by the 3:4:6:8:12.
Remember, you only need to provide density-specific drawables for bitmap files (.png, .jpg, or .gif) and Nine-Patch files (.9.png). If you use XML files to define drawable resources (eg. shapes), just put one copy in the default drawable directory.
If you ever have to accomodate really large or odd aspect ratios, create specific folders for these as well, using the flags for this, eg. sw, long, large, etc.
And no need to draw the background twice. Therefore set a style with <item name="android:windowBackground">#null</item>

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