How to use Musemage to correct 'converging verticals' effect

First open a picture you want to correct, and then select “Lens Effect” tab in the right of board.

Select “Perspective” to open “Perspective” dialog panel.

In dialog panel, drag the slider of “Vertical Perspective” to left.

The architectures now become vertical.

 If you want keep your image size in original resolution, you can drag “Scale” slider to let image fill the board.

 
Or you can click “OK” directly after in “Perspective” and then use “Clip” tools to clip available area out of the picture.