Since Adobe Photoshop CS5, we’ve had the tool Content-Aware, which can be used in lots of forms. http://photography.tutsplus.com/tutorials/photo-retouching-in-adobe-photoshop-with-content-aware-in-60-seconds--cms-25359?utm_campaign=yt_tutsplus_jlq90ehmud0&utm_medium=referral&utm_source=youtube.com&utm_content=description

The Spot heal brush will let you remove imperfections or unwanted aspects from a photo quickly and smoothly by sampling the area around your brush and using it to colour over the problem.

Content Aware Fill can recreate in missing aspects of a photograph based on the rest of your selection. It is powerful, but best used for less detailed or obvious areas like grass or the sea.

The patch tool is similar to fill but allows you to select something and drag it to the area you’d like it to use as a reference.

Finally, content-aware move will let you shift something in your image elsewhere and automatically fill in the gap. There’s also an option to extend the subject rather than moving it, another handy tool to fill in missing areas.