Cropping circular area from bitmap in Android

Question

I have a bitmap and I want to crop a circular region from this bitmap. All pixels outside the circle should be transparent. How can I do this?

Answer 1

After long brainstorming I have found the solution

public Bitmap getCroppedBitmap(Bitmap bitmap) {
    Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
            bitmap.getHeight(), Config.ARGB_8888);
    Canvas canvas = new Canvas(output);

    final int color = 0xff424242;
    final Paint paint = new Paint();
    final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

    paint.setAntiAlias(true);
    canvas.drawARGB(0, 0, 0, 0);
    paint.setColor(color);
    // canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
    canvas.drawCircle(bitmap.getWidth() / 2, bitmap.getHeight() / 2,
            bitmap.getWidth() / 2, paint);
    paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
    canvas.drawBitmap(bitmap, rect, rect, paint);
    //Bitmap _bmp = Bitmap.createScaledBitmap(output, 60, 60, false);
    //return _bmp;
    return output;
}

Answer 2

@Gene made a comment on the answer above that suggested using clipPath as an option for cropping an image as a circle.

The following is a clean implementation of this:

    public static Bitmap GetBitmapClippedCircle(Bitmap bitmap) {

        final int width = bitmap.getWidth();
        final int height = bitmap.getHeight();
        final Bitmap outputBitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);

        final Path path = new Path();
        path.addCircle(
                  (float)(width / 2)
                , (float)(height / 2)
                , (float) Math.min(width, (height / 2))
                , Path.Direction.CCW);

        final Canvas canvas = new Canvas(outputBitmap);
        canvas.clipPath(path);
        canvas.drawBitmap(bitmap, 0, 0, null);
        return outputBitmap;
    }

This could be added to a utility class.

Answer 3

you can use this code, it will work

 private Bitmap getCircleBitmap(Bitmap bitmap) {
        final Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
                bitmap.getHeight(), Bitmap.Config.ARGB_8888);
        final Canvas canvas = new Canvas(output);

        final int color = Color.RED;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
        final RectF rectF = new RectF(rect);

        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        canvas.drawOval(rectF, paint);

        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);

        bitmap.recycle();

        return output;
    }

Answer 4

you can use this code, it will work

public Bitmap getRoundedShape(Bitmap scaleBitmapImage) {
    int targetWidth = 110;
    int targetHeight = 110;
    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;
}

Answer 5

Here is Kotlin variant using extension method

/**
 * Creates new circular bitmap based on original one.
 */
fun Bitmap.getCircularBitmap(config: Bitmap.Config = Bitmap.Config.ARGB_8888): Bitmap {
    // circle configuration
    val circlePaint = Paint().apply { isAntiAlias = true }
    val circleRadius = Math.max(width, height) / 2f

    // output bitmap
    val outputBitmapPaint = Paint(circlePaint).apply { xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC_IN) }
    val outputBounds = Rect(0, 0, width, height)
    val output = Bitmap.createBitmap(width, height, config)

    return Canvas(output).run {
        drawCircle(circleRadius, circleRadius, circleRadius, circlePaint)
        drawBitmap(this@getCircularBitmap, outputBounds, outputBounds, outputBitmapPaint)
        output
    }
}

Answer 6

Now, Right answer:

private Bitmap getCroppedBitmap(Bitmap bitmap, Integer cx, Integer cy, Integer radius) {
    int diam = radius << 1;
    Bitmap targetBitmap = Bitmap.createBitmap(diam, diam, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(targetBitmap);
    final int color = 0xff424242;
    final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    canvas.drawARGB(0, 0, 0, 0);
    paint.setColor(color);
    canvas.drawCircle(radius, radius, radius, paint);
    paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
    canvas.drawBitmap(bitmap, -cx+radius, -cy+radius, paint);
    return targetBitmap;
}