bug fix for markRCNN drawBox

// Draw the predicted bounding box, colorize and show the mask on the image
void ThreadedMaskRCNN::drawBox(Mat& target, int classId, float conf, Rect box, Mat& objectMask)
{
	//Draw a rectangle displaying the bounding box
	rectangle(target, Point(box.x, box.y), Point(box.x + box.width, box.y + box.height), Scalar(255, 178, 50), 3);

	//Get the label for the class name and its confidence
	string label = format("%.2f", conf);
	if (!classes.empty())
	{
		CV_Assert(classId < (int)classes.size());
		label = classes[classId] + ":" + label;
	}
	std::cout << label << std::endl;


	//Display the label at the top of the bounding box
	int baseLine;
	Size labelSize = getTextSize(label, FONT_HERSHEY_SIMPLEX, 0.5, 1, &baseLine);
	box.y = max(box.y, labelSize.height);
	rectangle(target, Point(box.x, box.y - round(1.5 * labelSize.height)), Point(box.x + round(1.5 * labelSize.width), box.y + baseLine), Scalar(255, 255, 255), FILLED);
	putText(target, label, Point(box.x, box.y), FONT_HERSHEY_SIMPLEX, 0.75, Scalar(0, 0, 0), 1);

	Scalar color = colors[classId % colors.size()];

	// Resize the mask, threshold, color and apply it on the image
	resize(objectMask, objectMask, Size(box.width, box.height));
	Mat mask = (objectMask > maskThreshold);
	
	// bug fix
	cv::Rect mask_roi;
	mask_roi = cv::Rect(0, 0, box.width, box.height);
	if (!(0 <= box.x && 0 <= box.width && box.x + box.width <= target.cols &&
		0 <= box.y && 0 <= box.height && box.y + box.height <= target.rows))
	{
		if (box.x + box.width > target.cols) {
			int last_width = box.width;
			box.width = target.cols - box.x;
			mask_roi.width -= last_width - box.width;
		}
		if (box.y + box.height > target.rows) {
			int last_height = box.height;
			box.height = target.rows - box.y;
			mask_roi.height -= last_height - box.height;
		}

		std::cout << "roi error:" << box.x << ", " << box.y << ", " << box.width << ", " << box.height << ", "
			<< target.cols << ", " << target.rows << std::endl;
	}
		
	Mat coloredRoi = (0.3 * color + 0.7 * target(box));
	coloredRoi.convertTo(coloredRoi, CV_8UC3);

	// Draw the contours on the image
	vector<Mat> contours;
	Mat hierarchy;
	mask.convertTo(mask, CV_8U);

	findContours(mask, contours, hierarchy, RETR_CCOMP, CHAIN_APPROX_SIMPLE);
	drawContours(coloredRoi, contours, -1, color, 5, LINE_8, hierarchy, 100);
	coloredRoi.copyTo(target(box), mask(mask_roi));
}