1 | initial version |
you have to declare your callback function, before you use it in the code
(also, you need a different signature !). like this:
// declaration:
void bluecolor_callback(int position, void*);
int main() {
...
// you HAVE TO use c++, not the deprecated c-api calls !!!!!
cv::createTrackbar("Blue", "Color", 0, 1, bluecolor_callback);
...
}
// definition:
void bluecolor_callback(int position, void*) {
... some code
}
please also have another look at the tutorial