How to trim empty space in OpenCV?

Question

C++ / C#

Greetings!
There is a picture inserted on a black background in an arbitrary place,
how to crop this black background in the least expensive way, provided that the background is free of interference, i.e. completely #000 ?

Answer 1

В общем либо пробегаться по всей картинке и искать первый попавшийся пиксель по горизонтали/вертикале по обеим сторонам, либо docs.opencv.org/2.4/doc/tutorials/imgproc/shapedes...