Android resize bitmap keeping aspect ratio

Question

I have a custom view (1066 x 738), and I am passing a bitmap image (720x343). I want to scale the bitmap to fit in the custom view without exceeding the bound of the parent.

enter image description here

I want to achieve something like this:

enter image description here

How should I calculate the bitmap size?

How I calculate the new width/height:

    public static Bitmap getScaledBitmap(Bitmap b, int reqWidth, int reqHeight)
    {
        int bWidth = b.getWidth();
        int bHeight = b.getHeight();

        int nWidth = reqWidth;
        int nHeight = reqHeight;

        float parentRatio = (float) reqHeight / reqWidth;

        nHeight = bHeight;
        nWidth = (int) (reqWidth * parentRatio);

        return Bitmap.createScaledBitmap(b, nWidth, nHeight, true);
    }

But all I am achieving is this:

enter image description here

You could add a `scaleType` flag to your custom view's XML. http://developer.android.com/reference/android/widget/ImageView.ScaleType.html — Brett Haines, Jul 25 '14 at 18:04
Ah, I (wrongly) assumed your custom view extended ImageView... my fault — Brett Haines, Jul 25 '14 at 18:08

score 67 · Accepted Answer · answered Jul 25 '14 at 18:19

67

You should try using a transformation matrix built for ScaleToFit.CENTER. For example:

Matrix m = new Matrix();
m.setRectToRect(new RectF(0, 0, b.getWidth(), b.getHeight()), new RectF(0, 0, reqWidth, reqHeight), Matrix.ScaleToFit.CENTER);
return Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), m, true);

answered Jul 25 '14 at 18:19

matiash

54,791
16
125
154

1

not working for me. I tried reducing the image size, in resolutions, using this, but didn't work. – Narendra Singh May 11 '15 at 06:07
1

@DroidWormNarendra you can then call `Bitmap.createScaledBitmap(out, reqWidth, reqHeight, false);` ,this will reduce image size. – zionpi Jul 20 '15 at 02:42
@matiash , Please give a look on this issue http://stackoverflow.com/questions/42927337/scaling-bitmaps-of-huge-images-from-url-into-image-view-according-to-device-reso – user2028 Mar 22 '17 at 10:32
working for me.. – Rakesh Yadav Aug 10 '17 at 04:28

Android resize bitmap keeping aspect ratio

1 Answers1

Linked