I am using this image. I would like to have only the human part from this image. I don't want the background of this image.
How to do this? Any logic, links or the best and simple way?
here is the thing i want Link but i want this in objective c
There is no easy and fast way to satisfy your requirements. For the beginning you can learn how to detect objects in OpenCV.
After this you can check haarcascade_fullbody.xml from OpenCV sources. This cascade is for detecting bodies, open it in text editor, there is additional information in header. Anyway, I'm not sure that existing cascade is too accurate for your needs.
From iOS5 and above you can user face detection API. By using FaceDetection APi you can easily find the face of the person. For reference and sample code here is the link.
All the best !!!
For ios5.1+, using a CIDetector and CIFaceFeature class can be easily face recognition.
Body recognition, is you will need to use opencv library. Not yet supported by apple.
Have a look at this: http://niw.at/articles/2009/03/14/using-opencv-on-iphone/en
来源：https://stackoverflow.com/questions/15131768/how-to-get-a-single-entity-from-an-image