Develop Reference

Android splash screen image that occupies full screen width and height

I am trying to create a splash screen image that scales well for each screen size.
I am trying to determine if I am misunderstanding how pixel densities function.
According to the documentation,
To create alternative bitmap drawables for different densities, you
should follow the 3:4:6:8:12:16 scaling ratio between the six primary
densities. For example, if you have a bitmap drawable that's 48x48
pixels for medium-density screens, all the different sizes should be:
36x36 (0.75x) for low-density (ldpi)
48x48 (1.0x baseline) for medium-density (mdpi)
72x72 (1.5x) for high-density (hdpi)
96x96 (2.0x) for extra-high-density (xhdpi)
144x144 (3.0x) for extra-extra-high-density (xxhdpi)
192x192 (4.0x) for extra-extra-extra-high-density (xxxhdpi)
Now, I take this to mean that a 192x192 image will occupy the same amount of screen space on an xxxhdpi display as a 48x48 pixel image on a standard display.
That means that if I want a full screen image for a Google Pixel 2 display which is 1080px by 1920px and has an xxhdpi density of 2.6 then I need an image that is 1080 * 2.6 = 2808px by 1920 * 2.6 = 4992px.
Is this logic correct?

Image size for all screen devices

I have PSD, resolution of that is 1080X1920, it contains a Dot image whose resolution is 22X22.
I have cropped that image and put it in my res folder.
My question is how would Android know that the image is for 1080X1920 screen. It would open the same image bigger in small screen and smaller in 2560x1440 resolution.
Is there a way other than putting different images for each screen sizes to tell android to use the image for specific screen size and scale for other screens

use directly https://romannurik.github.io/AndroidAssetStudio/
For example, two devices that both report a screen size of normal
might have actual screen sizes and aspect ratios that are slightly
different when measured by hand. Similarly, two devices that report a
screen density of hdpi might have real pixel densities that are
slightly different. Android makes these differences abstract to
applications, so you can provide UI designed for the generalized sizes
and densities and let the system handle any final adjustments as
necessary
You have to create different dimen , layout , images and icon files to support all devices.
changes in screen density.
xlarge screens are at least 960dp x 720dp
large screens are at least 640dp x 480dp
normal screens are at least 470dp x 320dp
small screens are at least 426dp x 320dp
Make this layout files, so that it will be same for all devices.
Give padding ,margin ,font and all properties as per devices.
res/layout/main_activity.xml # For handsets (smaller than 600dp available width)
res/layout-sw600dp/main_activity.xml # For 7” tablets (600dp wide and bigger)
res/layout-sw720dp/main_activity.xml # For 10” tablets (720dp wide and bigger)
For Layout ,
res/layout/my_layout.xml // layout for normal screen size ("default")
res/layout-large/my_layout.xml // layout for large screen size
res/layout-xlarge/my_layout.xml // layout for extra-large screen size
res/layout-xlarge-land/my_layout.xml // layout for extra-large in landscape orientation
For Images
res/drawable-mdpi/graphic.png // bitmap for medium-density
res/drawable-hdpi/graphic.png // bitmap for high-density
res/drawable-xhdpi/graphic.png // bitmap for extra-high-density
res/drawable-xxhdpi/graphic.png // bitmap for extra-extra-high-density
For Icon
res/mipmap-mdpi/my_icon.png // launcher icon for medium-density
res/mipmap-hdpi/my_icon.png // launcher icon for high-density
res/mipmap-xhdpi/my_icon.png // launcher icon for extra-high-density
res/mipmap-xxhdpi/my_icon.png // launcher icon for extra-extra-high-density
res/mipmap-xxxhdpi/my_icon.png // launcher icon for extra-extra-extra-high-density
For Launcher icon
36x36 (0.75x) for low-density
48x48 (1.0x baseline) for medium-density
72x72 (1.5x) for high-density
96x96 (2.0x) for extra-high-density
180x180 (3.0x) for extra-extra-high-density
192x192 (4.0x) for extra-extra-extra-high-density (launcher icon only; see note above)
Checkout Dimension and
Supporting Multiple Screens Official Documentaion.

Android Studio has a plugin called "Batch Drawable" install in your Android studio. This help to create images of different size.
Steps To import:
File-->Settings-->Plugin-->Browse Repositories-->Click install button.
Restart your Android studio, then you will be able to find "Batch Drawable" inside the file menu of Android Studio.
Link: https://github.com/winterDroid/android-drawable-importer-intellij-plugin

There is no more you have to do, just put the different resolution files into different drawable-xxx file is okay. Remember that all the pics MUST HAVE the same name but Android will not automatically to match the screen size for each pic is the file name is not matched. Good luck!

put largescale image in drawable folder.

How to get appropriate images in respective android Device in Android Studio

I'm designing the layout of Music Player. When I'm rendering it with the Nexus 5 virtual device, I'm not facing any problem at all
When I render the image with Nexus 7 it is showing the same image size.
Posting screenshot of my photo too.
Hope to get some solution from you guys.

You have to follow this to support multiple devices :
changes in screen density.
xlarge screens are at least 960dp x 720dp
large screens are at least 640dp x 480dp
normal screens are at least 470dp x 320dp
small screens are at least 426dp x 320dp
Make this layout files, so that it will be same for all devices.
res/layout/main_activity.xml # For handsets (smaller than 600dp available width)
res/layout-sw600dp/main_activity.xml # For 7” tablets (600dp wide and bigger)
res/layout-sw720dp/main_activity.xml # For 10” tablets (720dp wide and bigger)
For Layout ,
res/layout/my_layout.xml // layout for normal screen size ("default")
res/layout-large/my_layout.xml // layout for large screen size
res/layout-xlarge/my_layout.xml // layout for extra-large screen size
res/layout-xlarge-land/my_layout.xml // layout for extra-large in landscape orientation
For Images
res/drawable-mdpi/graphic.png // bitmap for medium-density
res/drawable-hdpi/graphic.png // bitmap for high-density
res/drawable-xhdpi/graphic.png // bitmap for extra-high-density
res/drawable-xxhdpi/graphic.png // bitmap for extra-extra-high-density
For Icon
res/mipmap-mdpi/my_icon.png // launcher icon for medium-density
res/mipmap-hdpi/my_icon.png // launcher icon for high-density
res/mipmap-xhdpi/my_icon.png // launcher icon for extra-high-density
res/mipmap-xxhdpi/my_icon.png // launcher icon for extra-extra-high-density
res/mipmap-xxxhdpi/my_icon.png // launcher icon for extra-extra-extra-high-density
For Launcher icon
36x36 (0.75x) for low-density
48x48 (1.0x baseline) for medium-density
72x72 (1.5x) for high-density
96x96 (2.0x) for extra-high-density
180x180 (3.0x) for extra-extra-high-density
192x192 (4.0x) for extra-extra-extra-high-density (launcher icon only; see note above)
NOTE: Always try to use SP whenever you deal with textSize, like textsize=12sp
Use predefined textAppearance:
It will set text size automatically as per device density.
<TextView android:textAppearance="?android:attr/textAppearanceSmall"/>
<TextView android:textAppearance="?android:attr/textAppearanceMedium"/>
<TextView android:textAppearance="?android:attr/textAppearanceLarge" />
Sample usage:
<TextView
style="#android:style/TextAppearance.Small"
android:text="Sample Text - Small" />
<TextView
style="#android:style/TextAppearance.Medium"
android:text="Sample Text - Medium" />
<TextView
style="#android:style/TextAppearance.Large"
android:text="Sample Text - Large" />
Please visit Supporting Multiple Screens

Background image size for all screens

I want to use background image in my app.But i am so confused about different screen sizes.I found this question:
Android: Background Image Size (in Pixel) which Support All Devices
But in answer he said xxxhdpi: 1280x1920 px but Lg G3 is xxxHdpi and screen resolution: 1440 x 2560
I need a roadmap.How should be my image sizes for all screens ? (mdpi,hdpi,xhdpi etc.)

Android devices' screen sizes in pixels and screen width in inches, can differ significantly from device to device.
To address this issue, google lets you use different resources per size/density category
See here for some more info.
Generally speaking, you must put the largest size image that you want to support for each dpi in the correct folder, and let android do the resizing.
You can also check the imageView's ScaleType attribute to choose how to scale the image to fit the view.
EDIT
the reason to use the different folders and not just one large image is that the larger the image, the more memory it consumes.
For example a 1920x1280 image is nice to have on a 1920 screen, but on a 320pixels screen the extra resolution is wasted and you have a lot of wasted memory used.

An easier way is to include one single image in your drawable directory, then, in the OnCreate function of your activity, create a bitmap to fit the screen and put it in an imageview that has width and height set to "wrap_content".
This should work for any device.

Read this link. In particular, I think what you're looking for is:
To create alternative bitmap drawables for different densities, you should follow the 3:4:6:8:12:16 scaling ratio between the six generalized densities. For example, if you have a bitmap drawable that's 48x48 pixels for medium-density screens, all the different sizes should be:
36x36 (0.75x) for low-density
48x48 (1.0x baseline) for medium-density
72x72 (1.5x) for high-density
96x96 (2.0x) for extra-high-density
180x180 (3.0x) for extra-extra-high-density
192x192 (4.0x) for extra-extra-extra-high-density
and also:
xlarge screens are at least 960dp x 720dp
large screens are at least 640dp x 480dp
normal screens are at least 470dp x 320dp
small screens are at least 426dp x 320dp

Optimized size and dpi for Android app images

My app has a background image and I would like to create different files of it for the sake of multiple screen support.
I sent this link (http://developer.android.com/guide/practices/screens_support.html) for a graphic designer but he asked me the dimensions in pixels that I want the images to be created with.
Considering that I have a graphic designer in my team and I don’t want to use a code to optimize the images loaded in memory (I only want to place the images in the correct folders for small, normal, large and xlarge screens), what are the most optimized size and dpi settings to generate it?
We are working with PNG files.
For the dpi we are following this:
ldpi Resources for low-density (ldpi) screens (~120dpi).
mdpi Resources for medium-density (mdpi) screens (~160dpi). (This is the baseline density.)
hdpi Resources for high-density (hdpi) screens (~240dpi).
xhdpi Resources for extra high-density (xhdpi) screens (~320dpi).
But for the dimensions I could only find this, which is in dp and not in px:
xlarge screens are at least 960dp x 720dp
large screens are at least 640dp x 480dp
normal screens are at least 470dp x 320dp
small screens are at least 426dp x 320dp

1 dp = 1 px on 160dpi screen.
But your best bet for screen dimens is to look here
http://developer.android.com/guide/practices/screens_support.html#testing
and scroll down to where is shows the screen dimens in pixels (eg: 1920x1080) (Table 3)
Then check which ones you need most by looking at the chart
http://developer.android.com/about/dashboards/index.html#Screens
but the first link will give you the most used screen dimensions in use by Android devices.