Setting frame size of QuickCam Pro 3000 with OpenCV?

Question

I\'m using OpenCV 2.4.6 to grab images with my old Logitech QuickCam Pro 3000 webcam. Using VideoCapture::set( CV_CAP_PROP_FRAME_WIDTH, ... ) I\'m not able to s

Answer 1

It seems that your camera was not initialized properly. The following code works for me.

using namespace cv;

[...]

VideoCapture capture(0);
capture.set(CV_CAP_PROP_FRAME_WIDTH, width);
capture.set(CV_CAP_PROP_FRAME_HEIGHT, height);

I experimented with it a bit and found the following issues:

1. capture.set returns 0 if capture was not initialized.
2. capture.set returns 0 if camera is busy (another process using it).

It is not guaranteed that calling VideoCapture::set will change camera resolution to your desired resolution. For example, with my Logitech HD Pro Webcam C290, setting resolution to 640x480 and 1920x1080 works. But when I try 1024x768, VideoCapture::set returns true, but actual resolution is set to 960x720. So, check the actual resolution after reading a frame.