Scaled Bitmap maintaining aspect ratio

Question

I would like to scale a Bitmap to a runtime dependant width and height, where the aspect ratio is maintained and the Bitmap fills the entire width

Answer 1

Here I have a tested solution where I create a scaled Bitmap out of a bitmap file:

    int scaleSize =1024;

    public Bitmap resizeImageForImageView(Bitmap bitmap) {
        Bitmap resizedBitmap = null;
        int originalWidth = bitmap.getWidth();
        int originalHeight = bitmap.getHeight();
        int newWidth = -1;
        int newHeight = -1;
        float multFactor = -1.0F;
        if(originalHeight > originalWidth) {
            newHeight = scaleSize ;
            multFactor = (float) originalWidth/(float) originalHeight;
            newWidth = (int) (newHeight*multFactor);
        } else if(originalWidth > originalHeight) {
            newWidth = scaleSize ;
            multFactor = (float) originalHeight/ (float)originalWidth;
            newHeight = (int) (newWidth*multFactor);
        } else if(originalHeight == originalWidth) {
            newHeight = scaleSize ;
            newWidth = scaleSize ;
        }
        resizedBitmap = Bitmap.createScaledBitmap(bitmap, newWidth, newHeight, false);
        return resizedBitmap;
    }

Notice that I need scaled Bitmaps which have a maximum size of 4096x4096 Pixels but the aspect ratio needs to be kept while resizing. If you need other values for width or height just replace the values "4096".

This is just an addition to the answer of Coen but the problem in his code is the line where he calculates the ratio. Dividing two Integers gives an Integer and if the result is < 1 it will be rounded to 0. So this throws the "divide by zero" exception.