John .... This is what you do.
Import your shot in JPG format after your usual editing.
Click on Automatic Correction. Click on Adjust Correction if you wish to fine tune, you may wish to if the auto correct is too boxy looking. Click on Save and Exit.
The green and blue lines on the RHS show the computation of the vertical and horizontal features
The shot will be saved with a slightly changed name so it won't get confused with the original JPEG.
Have another go.... its great fun.