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?

score 3 · Accepted Answer · answered Mar 28 '11 at 11:03

3

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

answered Mar 28 '11 at 11:03

ypnos

score 1 · Answer 2 · answered Mar 28 '11 at 12:30

1

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());

answered Mar 28 '11 at 12:30

t.dubrownik

4

Hmm.. that's very hackish. BTW. wouldn't it be easier to use /dev/stdin for that? – vartec Mar 28 '11 at 14:33
Yeah it would be easier, I was shamefully unaware of that special file:) – t.dubrownik Mar 28 '11 at 20:07

score 0 · Answer 3 · answered Mar 28 '11 at 10:55

0

No,

But if really you want to, you can stream stdin into a named pipe (mkfifo) and read from it.

answered Mar 28 '11 at 10:55

BenjaminB

3 Answers3