Tracking Specific Color / Tracking Object

        // Define the range of "blue" color in HSV colorspace

        Scalar lowerLimit = Scalar(60,100,100);

        Scalar upperLimit = Scalar(180,255,255);

        // Threshold the HSV image to get only blue color

        inRange(hsvImage, lowerLimit, upperLimit, mask);

        // Compute bitwise-AND of input image and mask

        bitwise_and(frame, frame, outputImage, mask=mask);

        // Run median filter on the output to smoothen it

        medianBlur(outputImage, outputImage, 5);

        if(trackingFlag)

        {

            // Check for all the values in 'hsvimage' that are within the specified range

            // and put the result in 'mask'

            inRange(hsvImage, Scalar(0, minSaturation, minValue), Scalar(180, 256, maxValue), mask);

            // Mix the specified channels

            int channels[] = {0, 0};

            hueImage.create(hsvImage.size(), hsvImage.depth());

            mixChannels(&hsvImage, 1, &hueImage, 1, channels, 1);

            if(trackingFlag < 0)

            {

                // Create images based on selected regions of interest

                Mat roi(hueImage, selectedRect), maskroi(mask, selectedRect);

                // Compute the histogram and normalize it

                calcHist(&roi, 1, 0, maskroi, hist, 1, &histSize, &histRanges);

                normalize(hist, hist, 0, 255, CV_MINMAX);

                trackingRect = selectedRect;

                trackingFlag = 1;

            }

            // Compute the histogram back projection

            calcBackProject(&hueImage, 1, 0, hist, backproj, &histRanges);

            backproj &= mask;

            RotatedRect rotatedTrackingRect = CamShift(backproj, trackingRect, TermCriteria(CV_TERMCRIT_EPS | CV_TERMCRIT_ITER, 10, 1));

            // Check if the area of trackingRect is too small

            if(trackingRect.area() <= 1)

            {

                // Use an offset value to make sure the trackingRect has a minimum size

                int cols = backproj.cols, rows = backproj.rows;

                int offset = MIN(rows, cols) + 1;

                trackingRect = Rect(trackingRect.x - offset, trackingRect.y - offset, trackingRect.x + offset, trackingRect.y + offset) & Rect(0, 0, cols, rows);

            }

            // Draw the ellipse on top of the image

            ellipse(image, rotatedTrackingRect, Scalar(0,255,0), 3, CV_AA);

        }