[android] How to convert a Drawable to a Bitmap?

I would like to set a certain Drawable as the device's wallpaper, but all wallpaper functions accept Bitmaps only. I cannot use WallpaperManager because I'm pre 2.1.

Also, my drawables are downloaded from the web and do not reside in R.drawable.

Android provides a non straight foward solution: BitmapDrawable. To get the Bitmap , we'll have to provide the resource id R.drawable.flower_pic to the a BitmapDrawable and then cast it to a Bitmap.

Bitmap bm = ((BitmapDrawable) getResources().getDrawable(R.drawable.flower_pic)).getBitmap();

A Drawable can be drawn onto a Canvas, and a Canvas can be backed by a Bitmap:

(Updated to handle a quick conversion for BitmapDrawables and to ensure that the Bitmap created has a valid size)

public static Bitmap drawableToBitmap (Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        return ((BitmapDrawable)drawable).getBitmap();
    }

    int width = drawable.getIntrinsicWidth();
    width = width > 0 ? width : 1;
    int height = drawable.getIntrinsicHeight();
    height = height > 0 ? height : 1;

    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap); 
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

    return bitmap;
}

So after looking (and using) of the other answers, seems they all handling ColorDrawable and PaintDrawable badly. (Especially on lollipop) seemed that Shaders were tweaked so solid blocks of colors were not handled correctly.

I am using the following code now:

public static Bitmap drawableToBitmap(Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        return ((BitmapDrawable) drawable).getBitmap();
    }

    // We ask for the bounds if they have been set as they would be most
    // correct, then we check we are  > 0
    final int width = !drawable.getBounds().isEmpty() ?
            drawable.getBounds().width() : drawable.getIntrinsicWidth();

    final int height = !drawable.getBounds().isEmpty() ?
            drawable.getBounds().height() : drawable.getIntrinsicHeight();

    // Now we check we are > 0
    final Bitmap bitmap = Bitmap.createBitmap(width <= 0 ? 1 : width, height <= 0 ? 1 : height,
            Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

    return bitmap;
}

Unlike the others, if you call setBounds on the Drawable before asking to turn it into a bitmap, it will draw the bitmap at the correct size!

if you are using kotlin the use below code. it'll work

// for using image path

val image = Drawable.createFromPath(path)
val bitmap = (image as BitmapDrawable).bitmap

Maybe this will help someone...

From PictureDrawable to Bitmap, use:

private Bitmap pictureDrawableToBitmap(PictureDrawable pictureDrawable){ 
    Bitmap bmp = Bitmap.createBitmap(pictureDrawable.getIntrinsicWidth(), pictureDrawable.getIntrinsicHeight(), Config.ARGB_8888); 
    Canvas canvas = new Canvas(bmp); 
    canvas.drawPicture(pictureDrawable.getPicture()); 
    return bmp; 
}

... implemented as such:

Bitmap bmp = pictureDrawableToBitmap((PictureDrawable) drawable);

Here is the nice Kotlin version of the answer provided by @Chris.Jenkins here: https://stackoverflow.com/a/27543712/1016462

fun Drawable.toBitmap(): Bitmap {
  if (this is BitmapDrawable) {
    return bitmap
  }

  val width = if (bounds.isEmpty) intrinsicWidth else bounds.width()
  val height = if (bounds.isEmpty) intrinsicHeight else bounds.height()

  return Bitmap.createBitmap(width.nonZero(), height.nonZero(), Bitmap.Config.ARGB_8888).also {
    val canvas = Canvas(it)
    setBounds(0, 0, canvas.width, canvas.height)
    draw(canvas)
  }
}

private fun Int.nonZero() = if (this <= 0) 1 else this

android-ktx has Drawable.toBitmap method: https://android.github.io/android-ktx/core-ktx/androidx.graphics.drawable/android.graphics.drawable.-drawable/to-bitmap.html

From Kotlin

val bitmap = myDrawable.toBitmap()

Here is better resolution

public static Bitmap drawableToBitmap (Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        return ((BitmapDrawable)drawable).getBitmap();
    }

    Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap); 
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

    return bitmap;
}

public static InputStream bitmapToInputStream(Bitmap bitmap) {
    int size = bitmap.getHeight() * bitmap.getRowBytes();
    ByteBuffer buffer = ByteBuffer.allocate(size);
    bitmap.copyPixelsToBuffer(buffer);
    return new ByteArrayInputStream(buffer.array());
}

Code from How to read drawable bits as InputStream

ImageWorker Library can convert bitmap to drawable or base64 and vice versa.

val bitmap: Bitmap? = ImageWorker.convert().drawableToBitmap(sourceDrawable)

Implementation

In Project Level Gradle

allprojects {
        repositories {
            ...
            maven { url 'https://jitpack.io' }
        }
    }

In Application Level Gradle

dependencies {
            implementation 'com.github.1AboveAll:ImageWorker:0.51'
    }

You can also store and retrieve bitmaps/drawables/base64 images from external.

Check here. https://github.com/1AboveAll/ImageWorker/edit/master/README.md

1) Drawable to Bitmap :

Bitmap mIcon = BitmapFactory.decodeResource(context.getResources(),R.drawable.icon);
// mImageView.setImageBitmap(mIcon);

2) Bitmap to Drawable :

Drawable mDrawable = new BitmapDrawable(getResources(), bitmap);
// mImageView.setDrawable(mDrawable);

BitmapFactory.decodeResource() automatically scales the bitmap, so your bitmap may turn out fuzzy. To prevent scaling, do this:

BitmapFactory.Options options = new BitmapFactory.Options();
options.inScaled = false;
Bitmap source = BitmapFactory.decodeResource(context.getResources(),
                                             R.drawable.resource_name, options);

or

InputStream is = context.getResources().openRawResource(R.drawable.resource_name)
bitmap = BitmapFactory.decodeStream(is);

Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon);

This will not work every time for example if your drawable is layer list drawable then it gives a null response, so as an alternative you need to draw your drawable into canvas then save as bitmap, please refer below a cup of code.

public void drawableToBitMap(Context context, int drawable, int widthPixels, int heightPixels) {
    try {
        File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) + "/", "drawable.png");
        FileOutputStream fOut = new FileOutputStream(file);
        Drawable drw = ResourcesCompat.getDrawable(context.getResources(), drawable, null);
        if (drw != null) {
            convertToBitmap(drw, widthPixels, heightPixels).compress(Bitmap.CompressFormat.PNG, 100, fOut);
        }
        fOut.flush();
        fOut.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

private Bitmap convertToBitmap(Drawable drawable, int widthPixels, int heightPixels) {
    Bitmap bitmap = Bitmap.createBitmap(widthPixels, heightPixels, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, widthPixels, heightPixels);
    drawable.draw(canvas);
    return bitmap;
}

above code save you're drawable as drawable.png in the download directory

public static Bitmap drawableToBitmap (Drawable drawable) {
    Bitmap bitmap = null;

    if (drawable instanceof BitmapDrawable) {
        BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
        if(bitmapDrawable.getBitmap() != null) {
            return bitmapDrawable.getBitmap();
        }
    }

    if(drawable.getIntrinsicWidth() <= 0 || drawable.getIntrinsicHeight() <= 0) {
        bitmap = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888); // Single color bitmap will be created of 1x1 pixel
    } else {
        bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
    }

    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);
    return bitmap;
}

This piece of code helps.

Bitmap icon = BitmapFactory.decodeResource(context.getResources(),
                                           R.drawable.icon_resource);

Here a version where the image gets downloaded.

String name = c.getString(str_url);
URL url_value = new URL(name);
ImageView profile = (ImageView)v.findViewById(R.id.vdo_icon);
if (profile != null) {
    Bitmap mIcon1 =
        BitmapFactory.decodeStream(url_value.openConnection().getInputStream());
    profile.setImageBitmap(mIcon1);
}

 // get image path from gallery
protected void onActivityResult(int requestCode, int resultcode, Intent intent) {
    super.onActivityResult(requestCode, resultcode, intent);

    if (requestCode == 1) {
        if (intent != null && resultcode == RESULT_OK) {             
            Uri selectedImage = intent.getData();

            String[] filePathColumn = {MediaStore.Images.Media.DATA};
            Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
            cursor.moveToFirst();
            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            filePath = cursor.getString(columnIndex);

            //display image using BitmapFactory

            cursor.close(); bmp = BitmapFactory.decodeFile(filepath); 
            iv.setBackgroundResource(0);
            iv.setImageBitmap(bmp);
        }
    }
}

METHOD 1 : Either you can directly convert to bitmap like this

Bitmap myLogo = BitmapFactory.decodeResource(context.getResources(), R.drawable.my_drawable);

METHOD 2 : You can even convert the resource into the drawable and from that you can get bitmap like this

Bitmap myLogo = ((BitmapDrawable)getResources().getDrawable(R.drawable.logo)).getBitmap();

For API > 22 getDrawable method moved to the ResourcesCompat class so for that you do something like this

Bitmap myLogo = ((BitmapDrawable) ResourcesCompat.getDrawable(context.getResources(), R.drawable.logo, null)).getBitmap();

Use this code.it will help you for achieving your goal.

 Bitmap bmp=BitmapFactory.decodeResource(getResources(), R.drawable.profileimage);
    if (bmp!=null) {
        Bitmap bitmap_round=getRoundedShape(bmp);
        if (bitmap_round!=null) {
            profileimage.setImageBitmap(bitmap_round);
        }
    }

  public Bitmap getRoundedShape(Bitmap scaleBitmapImage) {
    int targetWidth = 100;
    int targetHeight = 100;
    Bitmap targetBitmap = Bitmap.createBitmap(targetWidth, 
            targetHeight,Bitmap.Config.ARGB_8888);

    Canvas canvas = new Canvas(targetBitmap);
    Path path = new Path();
    path.addCircle(((float) targetWidth - 1) / 2,
            ((float) targetHeight - 1) / 2,
            (Math.min(((float) targetWidth), 
                    ((float) targetHeight)) / 2),
                    Path.Direction.CCW);

    canvas.clipPath(path);
    Bitmap sourceBitmap = scaleBitmapImage;
    canvas.drawBitmap(sourceBitmap, 
            new Rect(0, 0, sourceBitmap.getWidth(),
                    sourceBitmap.getHeight()), 
                    new Rect(0, 0, targetWidth, targetHeight), new Paint(Paint.FILTER_BITMAP_FLAG));
    return targetBitmap;
}

The latest androidx core library (androidx.core:core-ktx:1.2.0) now has an extension function: Drawable.toBitmap(...) to convert a Drawable to a Bitmap.

very simple

Bitmap tempBMP = BitmapFactory.decodeResource(getResources(),R.drawable.image);