The research team Google has developed an algorithm to eliminate stretching of the face that commonly occurs when shooting with lenses with wide angle lenses. And it’s not just a corrective distortion filter. The team presented the result at the annual Conference on computer graphics SIGGRAPH 2019.
Ultra wide angle lenses, such as those installed on smartphones for “wide angle selfie” provide an impressively wide review with one flaw – objects are stretched at the edges. The end result is distorted background scenery and faces.
The application of a simple correction filter perspective distortion “sets in order” image on the edges of the picture, but it is necessary to “bend” the perspective lines all over the photo. So the faces look better, but any straight lines on the objects of architecture or the skyline in the background are unnaturally curved.
The solution is to use different methods of treatment for the persons and the background. To do this, first, the algorithm determines what is shown in the photo, differentiating between face and background. Then create a map perspective correction all the pictures, but only applies to subject areas, thus retaining the straight lines of the background when the displacement of persons in the future.
According to the developers, the technology works perfectly and quickly, which underlines its “online” status.
Source — MIT