Hw2

cvQueryFrame(capture); must put before it can read a frame

cvCreateImage(cvSize(frame->width,frame->height), IPL_DEPTH_8U, 3);

nchannel 1=Gray, 2=Gray+transparent, 3=BGR, 4=BGR+transparent

cvCvtColor(frame, gray, CV_BGR2GRAY); =>convert color

cvThreshold( gray, bw, 90, 255, CV_THRESH_BINARY ); =>convert to binary color