ImageUtil.java

package io.hefuyi.listener.util;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.support.v8.renderscript.RenderScript;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;

public class ImageUtil {

    public static Drawable createBlurredImageFromBitmap(Bitmap bitmap, Context context, int inSampleSize) {

        RenderScript rs = RenderScript.create(context);
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inSampleSize = inSampleSize;

        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
        byte[] imageInByte = stream.toByteArray();
        ByteArrayInputStream bis = new ByteArrayInputStream(imageInByte);
        Bitmap blurTemplate = BitmapFactory.decodeStream(bis, null, options);

        final android.support.v8.renderscript.Allocation input = android.support.v8.renderscript.Allocation.createFromBitmap(rs, blurTemplate);
        final android.support.v8.renderscript.Allocation output = android.support.v8.renderscript.Allocation.createTyped(rs, input.getType());
        final android.support.v8.renderscript.ScriptIntrinsicBlur script = android.support.v8.renderscript.ScriptIntrinsicBlur.create(rs, android.support.v8.renderscript.Element.U8_4(rs));
        script.setRadius(4f);
        script.setInput(input);
        script.forEach(output);
        output.copyTo(blurTemplate);

        return new BitmapDrawable(context.getResources(), blurTemplate);
    }

}