C\c++ level three pointer as formal parameter __c++

Second-level pointers and three-level pointers as specific applications of formal parameters:

When a second pointer is used as a parameter, the memory allocation is performed outside the function. Functions only need to be related operations, the three-level pointer as a formal parameter, you can allocate space within the function.

Level three pointers as parameter codes:

int skindetect (unsigned char *frame, int _width, int _height, rect*** ppp_rect, int *skin_size) {int width = _width;

	int height = _height;
	Cv::mat src;

	Cv::mat Skinmask;
	Src.create (Height * 3/2, width, cv_8uc1);

	Skinmask.create (height, width, cv_8uc1);

	Skinmask = 0;

	Cv::mat element = Cv::getstructuringelement (Cv::morph_rect, Cv::size (7, 7));

	
	memcpy (Src.data, frame, Height * Width * 3/2 * sizeof (unsigned char));


	Gaussianblur (SRC, src, cv::size (5, 5), 2, 2);
	unsigned char *pyplane = src.data;
	unsigned char *puplane = src.data + height * width;
	unsigned char *pvplane = src.data + (height * width)/4 * 5;



	unsigned char *pmask = skinmask.data;  for (int i = 0; i < HEIGHT/2 i++) for (int j = 0; J < Width/2; J +) {unsigned char u = puplane[i * WIDTH/2
		+ j];
		unsigned char v = pvplane[i * WIDTH/2 + j];

		unsigned char y = pyplane[2 * I * width + 2 * j]; if ((U > && u< 127) && (V > && v < 173)/*&& (y > && y <) * *//skin {pmask[2 * i * width + 2 * j] = 255;

			Pmask[2 * I * width + 2 * j + 1] = 255;
			pmask[(2 * i + 1) * Width + 2 * j] = 255;

		pmask[(2 * i + 1) * Width + 2 * j + 1] = 255;
	}/*imshow ("Skinmask", skinmask);

	Cv::waitkey (0); * * Morphologyex (Skinmask, Skinmask, cv::morph_dilate, Element);
	Look for outermost contour STD::VECTOR&LT;STD::VECTOR&LT;CV::P oint>> contours;
	Std::vector<cv::vec4i> hierarchy;

	Findcontours (Skinmask, contours, hierarchy, cv::retr_external, Cv::chain_approx_none, CV::P oint ()); Cv::mat imagecontours = Cv::mat::zeros (Skinmask.size (), CV_8UC1);

	Minimum external rectangular canvas **ppp_rect = (rect**) malloc (contours.size () * sizeof (rect*));//malloc 1 int cnt = 0;

		for (int i = 0; I<contours.size (); i++) {if (Contours[i].size () <) continue;

		Draw Contour Drawcontours (imagecontours, contours, I, cv::scalar (255), 1, 8, hierarchy); The smallest outer-junction rectangle cv::rotatedrect rect = minarearect for drawing the contour (contours[i]);
		CV::P oint2f p[4];

		Rect.points (P);
		int minx = MIN4 (p[0].x, p[1].x, p[2].x, p[3].x);

		int miny = MIN4 (P[0].y, P[1].y, P[2].y, P[3].Y);
		int maxx = max4 (p[0].x, p[1].x, p[2].x, p[3].x);

		int maxy = max4 (P[0].y, P[1].y, P[2].y, P[3].Y);
		Cv::rect Rect2 (Minx, Miny, Maxx-minx, Maxy-miny);

		_rect ret_rect{Minx, Miny, Maxx-minx, maxy-miny};

		cout << Minx << Endl; (*ppp_rect)

		[CNT] = (rect*) malloc (sizeof (Rect))//malloc 2 memset ((*ppp_rect) [CNT], 0, sizeof (Rect));

		memcpy ((*ppp_rect) [CNT], &ret_rect, sizeof (rect));
		Rectangle (imagecontours, Rect2, Cv::scalar::all (255), 2);

	cnt++;
	} *skin_size = cnt;
	Std::cout << endl<<cnt << Std::endl;
	Imshow ("Minarearect", imagecontours);

	Cv::waitkey (); /*if (Pp_rect = = NULL) std::cout << "error" << std::endl;*//*for (int i = 0; i < cnt; i++) {std::cout &L
	t;< "<< i <<" area: << (*pp_rect) [i]->_x << Std::endl;
}*/	return 0;
 }