I am truing to show the camfeed into a window using imshow() but it needs waitKey() after each frame. Referred to a few aritcles on web that say highgui requires waitkey() to be called in order to get time to update the window.
Is there a workaround with cpp interface to accomplish this without use of waitKey() ?
You can try waitKey(0). That should work well.
waitKey(0) means wait for keypress infinitely.
Not what I am looking for.
yeah i am already working with waitKey(1)
I wanted get rid of it. I think it will a little cumbersome to do so... may i should ignore it.
Note on documentation: "This function is the only method in HighGUI that can fetch and handle events, so it needs to be called periodically for normal event processing unless HighGUI is used within an environment that takes care of event processing." Since this is the only method, you are pretty much stuck.
Try cv::startWindowThread() after opening the window with cv::namedWindows(). Makes your window more responsive if there is no waitKey around.....
this will not work 100 % of the time ... the interface is created for using with waitKey(). The interface openCV provides is mainly for debugging purposes. If you want a full blown GUI, you need to use QT or winforms or something like that.
Asked: 2014-02-05 13:19:06 -0600
Seen: 34,200 times
Last updated: Feb 06 '14
have a look at qt ? do you own gui.
static boost::once_flag cv_thread_flag = BOOST_ONCE_INIT; boost::call_once(cv_thread_flag, &cv::startWindowThread);
found this is page here: http://web.ics.purdue.edu/~yuanl/2011/08/ros-cvnamedwindow-doesnt-show-up/
don't Understand it.
@berak: I am not using qt for my application. Since everything is on main thread... i think i own the gui.
how's that related to your question ?
all i'm saying is - you don't have to use the highgui api, warts and all.
okay... you want me do my own gui. Actually final application won't be gui based. So i guess i shouldnt be putting much time into it right now. Just wanted to explore options for debugging purpose.
thanks for the help though.
hey, yea. another approach to it.
any way, don't worry too long about highgui's deficiances...
I used wait(1); sleep(3); image stayed around for 3 sec.
ahhh, keghn, nooo ...