Pablo Quemé Pablo Quemé - 5 months ago 43
Android Question

Scale Bitmap maintaining aspect ratio and fitting both width and height

I want to scale a bitmap maintaining the aspect ratio, but fitting the required dimensions. This answer scales the bitmap and maintains the aspect ratio, but leaves some blank space unless the image is a perfect square. I need to fill both width and height, just like the

FIT_XY
ScaleType property of an
ImageView
.

Answer

Based on Streets of Boston's answer, I made this method that scales and returns any Bitmap to a desired width and height, fitting both dimensions (no blank space!). It automatically adapts to more horizontal or more vertical images.

public Bitmap resizeBitmapFitXY(int width, int height, Bitmap bitmap){
    Bitmap background = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    float originalWidth = bitmap.getWidth(), originalHeight = bitmap.getHeight();
    Canvas canvas = new Canvas(background);
    float scale, xTranslation = 0.0f, yTranslation = 0.0f;
    if (originalWidth > originalHeight) {
        scale = height/originalHeight;
        xTranslation = (width - originalWidth * scale)/2.0f;
    }
    else {
        scale = width / originalWidth;
        yTranslation = (height - originalHeight * scale)/2.0f;
    }
    Matrix transformation = new Matrix();
    transformation.postTranslate(xTranslation, yTranslation);
    transformation.preScale(scale, scale);
    Paint paint = new Paint();
    paint.setFilterBitmap(true);
    canvas.drawBitmap(bitmap, transformation, paint);
    return background;
}