In PhotoShop:

  1. Open an image on which we add rounded corners or create blank image.
  2. Add a new layer on top, so image has its own layer under the newly created layer.
  3. Selected “Rounded Rectangle Tool” and draw rectangle on the new layer.
  4. Double click on the layer that you just drew the rounded rectangle on.
  5. In the Advanced Blending area, play with the Fill Opacity percentage. Make it 0% if real image (not blank) is underneath it.
  6. Click on the Paths tab., select the path, click on the little arrow button, in the upper right corner, and select “Make Selection…”.
  7. In the “Make Selection” option box, make sure Feather Radius is set to 0 pixels, and Anti–aliased IS checked.
  8. Finally, with the selection still pending action, go to Edit, Copy Merged. Create a new document, and leave the dimensions alone. In the new document, go to Edit, Paste. That’s it!