Android: Using linear gradient as background looks banded

Question

I'm trying to apply a linear gradient to my ListView. This is the content of my drawable xml:

 <?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient 
        android:startColor="#3A3C39" 
        android:endColor="#181818"
        android:angle="270"
     />
    <corners android:radius="0dp" />
</shape>

So I apply it to my ListView with:

android:background="@drawable/shape_background_grey"

It works but it looks very "banded" on emulator and on a real device too.

Is there any way to reduce this "behaviour"?

Just an update: adding getWindow().setFormat(PixelFormat.RGBA_8888); getWindow().addFlags(WindowManager.LayoutParams.FLAG_DITHER); in the onCreate method seems does the trick also for hdpi with amoled screen (N1/Desire) — Francesco Laurita, Jun 08 '10 at 13:40
`@Francesco` Great! It helped on my **Galaxy S** with **Android 2.2**. Please convert your useful comment to an answer, so people can vote for it. — java.is.for.desktop, Jun 10 '11 at 22:49

Francesco Laurita · Accepted Answer · 2011-06-11T12:52:04.423

85

As Romain Guy suggests:

listView.getBackground().setDither(true);

solves my problem

If this is not enough especially for AMOLED and/or hdpi devices try this:

@Override
public void onAttachedToWindow() {
    super.onAttachedToWindow();
    Window window = getWindow();
    window.setFormat(PixelFormat.RGBA_8888);
}

edited Jun 11 '11 at 12:52

answered May 28 '10 at 19:50

Francesco Laurita

22,784
7
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This not works on android 1.6 and above. See my other comment – Francesco Laurita May 31 '10 at 09:53
@Artem In my case, on Android >= 1.6 `listView.getBackground().setDither(true);` wont work, I had to override the `onAttachedToWindow` method. – Francesco Laurita Jun 17 '11 at 06:32
4

setDither() is now deprecated – GuillermoMP Jan 14 '16 at 10:55

score 40 · Answer 2 · answered May 28 '10 at 17:36

40

You can simply enable dithering on your Drawable object.

answered May 28 '10 at 17:36

Romain Guy

95,351
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1

Yes it works! Ty very much. BTW I tried to use this property into the drawable xml definition but as I read better into the documentation, this property is supported only for the selector element. – Francesco Laurita May 28 '10 at 19:47
Unfortunly this not works on Android version > 1.5. I tested on real device with Android 1.6 and Android 1.5. Adding dither to my drawable gradient not works. The devices are both 320 x 480 (180 ppi). Any suggestion? Tnx – Francesco Laurita May 31 '10 at 09:52
5

`setDither()` was deprecated in API level 23. This property is now ignored. – Tot Zam Mar 17 '17 at 00:58

score 9 · Answer 3 · answered Jun 10 '11 at 18:03

9

Put this in your Activity:

@Override
public void onAttachedToWindow() {
    super.onAttachedToWindow();
    Window window = getWindow();
    window.setFormat(PixelFormat.RGBA_8888);
}

answered Jun 10 '11 at 18:03

Miša Peić

6,373
1
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15

score 3 · Answer 4 · answered Mar 17 '15 at 16:11

3

If the dither and RGBA_888 setting don't help on some phones, the solution can be to set the element layerType to software, to disable the hardware acceleration

android:layerType="software"

This fixed my problem on a Samsung S5 phone.

answered Mar 17 '15 at 16:11

peter.bartos

10,745
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60

score 3 · Answer 5 · edited Nov 10 '11 at 09:29

3

For me on HTC Desire works like this

window.getDecorView().getBackground().setDither(true);

edited Nov 10 '11 at 09:29

Paresh Mayani

122,920
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290

answered Jun 11 '11 at 08:19

Sebastian

206
3
6

1

`setDither()` was deprecated in API level 23. This property is now ignored. – Tot Zam Mar 17 '17 at 00:58

score 2 · Answer 6 · answered Feb 13 '14 at 12:05

For me the banding disappeared when I set the android:useLevel="true" on the gradient: gradient_dark.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <gradient android:startColor="#464646"
        android:endColor="#323232"
        android:angle="270"
        android:type="linear"
        android:useLevel="true"
         />
</shape>

But first I tried using a Layer-List with a "noise" drawable to remove the banding, it helps but there is still some banding.

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:drawable="@drawable/gradient_dark"/>
    <item>
        <bitmap
            android:gravity="center"
            android:src="@drawable/noise_repeater"
            android:tileMode="repeat" />
    </item>

</layer-list>

The "noise_repeater" drawable i created and used

enter image description here

score 0 · Answer 7 · edited May 23 '17 at 11:54

The only thing that worked for me was to set a slightly-transparent alpha channel on both the startColor and endColor.

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient 
        android:startColor="#FE3A3C39" 
        android:endColor="#FE181818"
        android:angle="270"
     />
</shape>

I got the idea to try this from this other SO question: android:dither=“true” does not dither, what's wrong?

Android: Using linear gradient as background looks banded

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