So im creating a new app and I was wondering if i could only make one icon(technically two but one is 512*512 for the play store). So ill just make a max size icon for xxhdpi will lower res phones scale correctly, or would i actually have to make one for each dpi level. If that is the case, are there any tools that creates the different sizes for me?
You have to make one for each screen density. There are tools available to assist you in this: http://romannurik.github.io/AndroidAssetStudio/index.html
You really have to have an icon for each density value, otherwise you will have a 512*512 icon being used in a ldpi phone, which is very inefficient, as for ldpi phones you should use a 32x32 icon instead. Just use an image editor and resize your original icon or use on-line tools to resize it for you. ynnadkrap has a good example of a tool you can use to get your icons.
Since Android 4.3 (Jelly Bean) we can now make use of the res/mipmap folders to store "mipmap" images.
For example, Chrome for Android stores its icons in these folders instead of the more normal res/drawable folders.
How are these mipmap images different from the other familiar drawable images?
I see that in my manifest, we use the #mipmap/ qualifier, instead of #drawable/, which makes sense given the resource folder name:
<activity
android:name=".MipmapDemp"
android:icon="#mipmap/ic_launcher" />
References:
The Android 4.3 APIs document has the following to say:
Using a mipmap as the source for your bitmap or drawable is a simple
way to provide a quality image and various image scales, which can be
particularly useful if you expect your image to be scaled during an
animation.
Android 4.2 (API level 17) added support for mipmaps in the Bitmap
class—Android swaps the mip images in your Bitmap when you've supplied
a mipmap source and have enabled setHasMipMap(). Now in Android 4.3,
you can enable mipmaps for a BitmapDrawable object as well, by
providing a mipmap asset and setting the android:mipMap attribute in a
bitmap resource file or by calling hasMipMap().
I don't see anything in there that helps me to understand.
XML Bitmap resources have an android:mipMap property:
Boolean. Enables or disables the mipmap hint. See setHasMipMap() for
more information. Default value is false.
This does not apply to launcher icons as far as I can see.
The question was raised on Google Groups (The purpose of resource name "mipmap"?!), to which Romain Guy replied:
It's useful to provide an image at a larger resolution that would
normally be computed (for instance, on an mdpi device, Launcher might
want the larger hdpi icon to display large app shortcuts.)
I feel like this almost makes sense of it, but not quite.
I'm still inclined to go with Randy Sugianto's follow up:
What are the advantages of this? Is there any guide how to use
mipmaps, probably for better launcher icons?
Of course, Wikipedia has a page for "Mipmap", which refers to an older technique invented in 1983, that I can't quite relate to the current Android implementation.
Should we be storing all our app icons in res/mipmap folders these days, and what are the guidelines for these mipmap images?
Update #1
Here's a blog post that tries to explain it a bit.
Mipmapping for drawables in Android 4.3
But the image used in that blog post shows what looks like one file with many logos in it. This is not what I see in Chrome's mipmap folder.
Chrome's mipmap-hdpi folder contains three images. One is the Chrome logo, on its own.
Strangely, it is 72x72, not 48x48 which I would expect to see.
Perhaps that is all there is to this - we just need to keep bigger icons in the mipmap folders?
Update #2
The Android Developers Blog post of 23/10/2014 again confirms the idea of using the mipmap folders for application icons:
Getting Your Apps Ready for Nexus 6 and Nexus 9
When talking about the Nexus 6 screen density, the author writes:
It’s best practice to place your app icons in mipmap- folders (not the
drawable- folders) because they are used at resolutions different from
the device’s current density. For example, an xxxhdpi app icon can be
used on the launcher for an xxhdpi device.
Update #3
Note that Android Studio creates the ic_launcher.png icons in the mipmap... folders rather than the drawable... folders that Eclipse used to create them in.
There are two distinct uses of mipmaps:
For launcher icons when building density specific APKs. Some developers build separate APKs for every density, to keep the APK size down. However some launchers (shipped with some devices, or available on the Play Store) use larger icon sizes than the standard 48dp. Launchers use getDrawableForDensity and scale down if needed, rather than up, so the icons are high quality. For example on an hdpi tablet the launcher might load the xhdpi icon. By placing your launcher icon in the mipmap-xhdpi directory, it will not be stripped the way a drawable-xhdpi directory is when building an APK for hdpi devices. If you're building a single APK for all devices, then this doesn't really matter as the launcher can access the drawable resources for the desired density.
The actual mipmap API from 4.3. I haven't used this and am not familiar with it. It's not used by the Android Open Source Project launchers and I'm not aware of any other launcher using.
It seems Google have updated their docs since all these answers, so hopefully this will help someone else in future :) Just came across this question myself, while creating a new (new new) project.
TL;DR: drawables may be stripped out as part of dp-specific resource optimisation. Mipmaps will not be stripped.
Different home screen launcher apps on different devices show app launcher icons at various resolutions. When app resource optimization techniques remove resources for unused screen densities, launcher icons can wind up looking fuzzy because the launcher app has to upscale a lower-resolution icon for display. To avoid these display issues, apps should use the mipmap/ resource folders for launcher icons. The Android system preserves these resources regardless of density stripping, and ensures that launcher apps can pick icons with the best resolution for display.
(from http://developer.android.com/tools/projects/index.html#mipmap)
How are these mipmap images different from the other familiar drawable images?
Here is my two cents in trying to explain the difference. There are two cases you deal with when working with images in Android:
You want to load an image for your device density and you are going to use it "as is", without changing its actual size. In this case you should work with drawables and Android will give you the best fitting image.
You want to load an image for your device density, but this image is going to be scaled up or down. For instance this is needed when you want to show a bigger launcher icon, or you have an animation, which increases image's size. In such cases, to ensure best image quality, you should put your image into mipmap folder. What Android will do is, it will try to pick up the image from a higher density bucket instead of scaling it up. This will increase sharpness (quality) of the image.
Thus, the rule of thumb to decide where to put your image into would be:
Launcher icons always go into mipmap folder.
Images, which are often scaled up (or extremely scaled down) and whose quality is critical for the app, go into mipmap folder as well.
All other images are usual drawables.
The Android implementation of mipmaps in 4.3 is exactly the technique from 1983 explained in the Wikipedia article :)
Each bitmap image of the mipmap set is a downsized duplicate of the
main texture, but at a certain reduced level of detail. Although the
main texture would still be used when the view is sufficient to render
it in full detail, the renderer will switch to a suitable mipmap image
(...) when the texture is viewed from a distance or at a small size.
Although this is described as a technique for 3D graphics (as it mentions "viewing from a distance"), it applies just as well to 2D (translated as "drawn is a smaller space", i.e. "downscaled").
For a concrete Android example, imagine you have a View with a certain background drawable (in particular, a BitmapDrawable). You now use an animation to scale it to 0.15 of its original size. Normally, this would require downscaling the background bitmap for each frame. This "extreme" downscaling, however, may produce visual artifacts.
You can, however, provide a mipmap, which means that the image is already pre-rendered for a few specific scales (let's say 1.0, 0.5, and 0.25). Whenever the animation "crosses" the 0.5 threshold, instead of continuing to downscale the original, 1.0-sized image, it will switch to the 0.5 image and downscale it, which should provide a better result. And so forth as the animation continues.
This is a bit theoretical, since it's actually done by the renderer. According to the source of the Bitmap class, it's just a hint, and the renderer may or may not honor it.
/**
* Set a hint for the renderer responsible for drawing this bitmap
* indicating that it should attempt to use mipmaps when this bitmap
* is drawn scaled down.
*
* If you know that you are going to draw this bitmap at less than
* 50% of its original size, you may be able to obtain a higher
* quality by turning this property on.
*
* Note that if the renderer respects this hint it might have to
* allocate extra memory to hold the mipmap levels for this bitmap.
*
* This property is only a suggestion that can be ignored by the
* renderer. It is not guaranteed to have any effect.
*
* #param hasMipMap indicates whether the renderer should attempt
* to use mipmaps
*
* #see #hasMipMap()
*/
public final void setHasMipMap(boolean hasMipMap) {
nativeSetHasMipMap(mNativeBitmap, hasMipMap);
}
I'm not quite sure why this would be especially suitable for application icons, though. Although Android on tablets, as well as some launchers (e.g. GEL), request an icon "one density higher" to show it bigger, this is supposed to be done using the regular mechanism (i.e. drawable-xxxhdpi, &c).
One thing I mentioned in another thread that is worth pointing out -- if you are building different versions of your app for different densities, you should know about the "mipmap" resource directory. This is exactly like "drawable" resources, except it does not participate in density stripping when creating the different apk targets.
https://plus.google.com/105051985738280261832/posts/QTA9McYan1L
Since I was looking for an clarifying answer to this to determine the right type for notification icons, I'd like to add this clear statement to the topic. It's from http://developer.android.com/tools/help/image-asset-studio.html#saving
Note: Launcher icon files reside in a different location from that of
other icons. They are located in the mipmap/ folder. All other icon
files reside in the drawable/ folder of your project.
There are two cases you deal with when working with images in Android:
You want to load an image for your device density and you are going to use it “as is”, without changing its actual size. In this case you
should work with drawables and Android will give you the best fitting
image.
You want to load an image for your device density, but this image is going to be scaled up or down. For instance this is needed when you
want to show a bigger launcher icon, or you have an animation, which
increases image’s size. In such cases, to ensure best image quality,
you should put your image into mipmap folder. What Android will do is,
it will try to pick up the image from a higher density bucket instead
of scaling it up.
SO
Thus, the rule of thumb to decide where to put your image into would
be:
Launcher icons always go into mipmap folder.
Images, which are often scaled up (or extremely scaled down) and whose quality is critical for the app, go into mipmap folder as
well.
All other images are usual drawables.
Citation from this article.
When building separate apks for different densities, drawable folders for other densities get stripped. This will make the icons appear blurry in devices that use launcher icons of higher density.
Since, mipmap folders do not get stripped, it’s always best to use them for including the launcher icons.
When we build separate APKs for different densities, for the APK of the particular density, the drawable folders for other densities get stripped. This will make the icons appear blurry on devices that use launcher icons of higher density. Since mipmap folders do not get stripped, it's always best to use them for including the launcher icons.
res/
mipmap-mdpi/ic_launcher.png (48x48 pixels)
mipmap-hdpi/ic_launcher.png (72x72)
mipmap-xhdpi/ic_launcher.png (96x96)
mipmap-xxhdpi/ic_launcher.png (144x144)
mipmap-xxxhdpi/ic_launcher.png (192x192)
MipMap for app icon for launcher
http://android-developers.blogspot.co.uk/2014/10/getting-your-apps-ready-for-nexus-6-and.html
https://androidbycode.wordpress.com/2015/02/14/goodbye-launcher-drawables-hello-mipmaps/
If you build an APK for a target screen resolution like HDPI, the Android asset packageing tool,AAPT,can strip out the drawables for other resolution you don’t need.But if it’s in the mipmap folder,then these assets will stay in the APK, regardless of the target resolution.
The understanding I have about mipmap is more or less like this:
When an image needs to be drawn, given we have different screen sizes are resolutions, some scaling will have to take part.
If you have an image that is ok for a low end cell phone, when you scale it to the size of a 10" tablet you have to "invent" pixels that don't actually exist. This is done with some interpolation algorithm. The more amount of pixels that have to be invented, the longer the process takes and quality starts to fail. Best quality is obtained with more complex algorithms that take longer (average of surrounding pixles vs copy the nearest pixel for example).
To reduce the number of pixels that have to be invented, with mipmap you provide different sizes/rsolutions of the same image, and the system will choose the nearest image to the resolution that has to be rendered and do the scaling from there. This should reduce the number of invented pixels saving resources to be used in calculating these pixels to provide a good quality image.
I read about this in an article explaining a performance problem in libgdx when scaling images:
http://www.badlogicgames.com/wordpress/?p=1403
Is there a way to get Eclipse to automatically re-size images and put them in the appropriate drawable folders? When you add an image for the icon when you first create an Android project, it automatically re-sizes the icon and puts them in the appropriate folders. I know you're meant to scale images using a 3:4:6:8 scaling ratio (http://developer.android.com/guide/practices/screens_support.html). I'm wondering if there is a way that Eclipse does this automatically for images?
For re-size icons, right click select New/Other… or press Ctrl+N, select Android Icon Set, the default name for icons is ic_launcher, click Next, in Foreground select Image and Browser that image like to put as icon and is re-sized automatically
Is there a way to get Eclipse to automatically re-size images and put
them in the appropriate drawable folders?
NO, until now, you have to create your own resources defined for every "Screen Density", tools like android_img_resizer will work but can´t support all densities, what if you need resources with mhdpi or tvdpi density.
More info:
Supporting Multiple Screens - Using configuration qualifiers
Designing alternative layouts and drawables
Supporting Different Densities
For re-sizing the images in bulk i will recommend you this tool https://github.com/bearstouch/android_img_resizer . its easy to install and it support the new resolutions (xxxhdpi,xxhdpi) as the base image.Check it out.
I am working on an app which is able to add shortcuts icons to the homescreen.
What is the correct icon size for Android tablets? (Or better said, how to get it at runtime?) It seems to differ from what is written on this page.
I have switch on DisplayMetrics.densityDpi and change the icon size accordingly. But it does not work for all devices..Gnex seems to be ok, but my Galaxy Tab while beeing DisplayMetrics.DENSITY_MEDIUM device displays only 48x48px icon (as it is in guidelines), but usual launcher icons are 72x72 pixels and not 48x48 - it differs from guidelines? Is it possible that it is related to TouchWiz UI and thus it differs from pure Android? Or where is the problem? Also good to note, that apps itself displays correct launcher icon (it takes the icon from hdpi folder), but at runtime it looks like it is mdpi device:/
Thanks
Android tablets looks one bucket up, when looking for launcher icon..That means mdpi device will actually look into hdpi folder..
This code returns correct size for launcher icons
ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
int iconSize = am.getLauncherLargeIconSize();
Answer is based on this g+ post by Nick Butcher
best thing you use the android assets studio tool for this task .
it will automatically create the correct sizes and put them in the correct folders .
I've created a menu icon and included a 36x36, 48x48 and 72x72 in the ldpi, mdpi and hdpi drawable folders. It looks fine on all devices except honeycomb tablets, where it seems like the padding around the Android icons are bigger than on my custom icon. I've included a screenshot (see how much bigger my 'Resume Reading' icon is than the android 'Back' and 'My Library' icons are). How do I make my icon look like this?
I think I found the problem. When using the Android resource icon's on a tablet, I think it changes the padding in order for the icon to be used in the action bar. So when displaying them in a pop up menu at the bottom they are appearing much smaller than they should be. The solution is to copy the android resources into our own resource folder as it says to do here http://developer.android.com/guide/practices/ui_guidelines/icon_design_menu.html
Most of your Tablets are not hdpi, they are xhdpi. While the Icon Design Guidelines are useful, they don't give the whole story. Consider reading Supporting Multiple Screens. Here, they tell you further ratios and dimensions. To save you some time, resources should be 3ldpi:4mdpi:6hdpi:8xhdpi meaning that your xhdpi icon should be 96 x 96. Please, read the whole document, though. It is insanely useful.