Question

In Android, an ImageView is a rectangle by default. How can I make it a rounded rectangle (clip off all 4 corners of my Bitmap to be rounded rectangles) in the ImageView?

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Note that from 2021 onwards, simply use ShapeableImageView

Answer 1

This is pretty late in response, but for anyone else that is looking for this, you can do the following code to manually round the corners of your images.

http://www.ruibm.com/?p=184

This isn’t my code, but I’ve used it and it’s works wonderfully. I used it as a helper within an ImageHelper class and extended it just a bit to pass in the amount of feathering I need for a given image.

Final code looks like this:

package com.company.app.utils;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;

public class ImageHelper {
    public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, int pixels) {
        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());
        final RectF rectF = new RectF(rect);
        final float roundPx = pixels;

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

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

        return output;
    }
}