OpenCV: reading image from std::in?

Question

Is there some way of using OpenCV's imread function to read from std::in?

Mat imread( const string& filename, int flags=1 );

Function accepts only filename, but is there some "magic" value for stdin?

Answer 1

OpenCV provides imdecode functions that work on buffers instead of filename. You would need to read stdin into a buffer first.

http://opencv.willowgarage.com/documentation/cpp/reading_and_writing_images_and_video.html

Answer 2

If you want a very quick hack, here's something that seems to work on Linux:

#include <unistd.h>

/* snip */ 

std::stringstream ss;
ss << "/proc/" << getpid() << "/fd/0";

cv::Mat m = cv::imread(ss.str());