Imagine spending the whole weekend taking lovely pictures of landscapes... only to arrive home and see that the skyline in some of them is completely tilted.
Don't worry, there's an easy way to fix it. Simply use Rotation Pilot and restore the horizon to its original position while keeping the same image quality as the original photo.
This is how it works: load the picture and draw a line with your mouse along the horizon (the tilted one, not the one you'd like to have). The program will automatically rotate the picture to the desired position. If there's any cropping or smoothing needed, you can also enable those options and let Rotation Pilot do the job, though the cropping will obviously affect the borders of the original photo. The program also includes rotating, resizing and mirroring options for further photo edition.
With Rotation Pilot you can easily fix visual slopes and tilted horizons in your digital photos.