EDPF: A Realtime Parameter-Free Edge Segment Detector 实现

#include "EDLib.h" EdgeMap *DetectEdgesByED(unsigned char *srcImg, int width, int height, GradientOperator op, int GRADIENT_THRESH, int ANCHOR_THRESH, double smoothingSigma) { GaussianSmooth(srcImg, smoothingSigma, width, height); unsigned char* EdgeAreas; unsigned char* EdgeDirections; EdgeAreas = (unsigned char *)malloc(sizeof(unsigned char)*width*height); EdgeDirections = (unsigned char *)malloc(sizeof(unsigned char)*width*height); memset(EdgeAreas,0x00,sizeof(unsigned char)*width*height); memset(EdgeDirections,0x00,sizeof(unsigned char)*width*height); Edge_Areas_Directions(srcImg, width, height, op, GRADIENT_THRESH, EdgeAreas, EdgeDirections); unsigned char* AnchorMap; AnchorMap = (unsigned char *)malloc(sizeof(unsigned char)*width*height); memset(AnchorMap,0x00,sizeof(unsigned char)*width*height); vector<Pixel> anchor; FindAnchor(EdgeAreas, EdgeDirections, width, height, ANCHOR_THRESH, AnchorMap, anchor); EdgeMap *edgemap; edgemap = (EdgeMap *)malloc(sizeof(EdgeMap)*width*height); memset(edgemap,0x00,sizeof(EdgeMap)*width*height); LinkAnchor(EdgeAreas, EdgeDirections, width, height, GRADIENT_THRESH, AnchorMap, edgemap); edgemap->width = width; edgemap->height = height; return edgemap; free (EdgeAreas); free (EdgeDirections); free (AnchorMap); free (edgemap); } void GaussianSmooth(unsigned char* srcImg, double sigma, int width, int height) { int ksize = 5; sigma = sigma > 0 ? sigma : -sigma; //计算一维高斯核 double *kernel = new double[ksize]; double scale = -0.5/(sigma*sigma); const double PI = 3.141592653; double cons = 1/sqrt(-scale / PI); double sum = 0; int kcenter = ksize/2; int i = 0, j = 0; for(i = 0; i < ksize; i++) { int x = i - kcenter; *(kernel+i) = cons * exp(x * x * scale);//一维高斯函数 sum += *(kernel+i); } //归一化,确保高斯权值在[0,1]之间 for(i = 0; i < ksize; i++) { *(kernel+i) /= sum; } unsigned char* temp; unsigned char* temp1; temp = (unsigned char *)malloc(sizeof(unsigned char)*width*height); temp1 = (unsigned char *)malloc(sizeof(unsigned char)*width*height); memset(temp,0x00,sizeof(unsigned char)*width*height); memset(temp1,0x00,sizeof(unsigned char)*width*height); //x方向一维高斯模糊 for(int y = 0; y < height; y++) { for(int x = 0; x < width; x++) { double mul = 0; sum = 0; for(i = -kcenter; i <= kcenter; i++) { if((x+i) >= 0 && (x+i) < width) { mul +=srcImg[y*width + (x+i)]*(*(kernel+kcenter+i)); sum += (*(kernel+kcenter+i)); } } temp1[y*width + x] = mul/sum; } } //y方向一维高斯模糊 for(int x = 0; x < width; x++) { for(int y = 0; y < height; y++) { double mul = 0; sum = 0; for(i = -kcenter; i <= kcenter; i++) { if((y+i) >= 0 && (y+i) < height) { mul += temp1[(y+i)*width + x]*(*(kernel+kcenter+i)); sum += (*(kernel+kcenter+i)); } } temp[y*width + x] = mul/sum; } } memcpy(srcImg,temp,height*width*sizeof(unsigned char)); delete[] kernel; free (temp); free (temp1); } void Edge_Areas_Directions(unsigned char* srcImg, int width, int height, GradientOperator op, int GRADIENT_THRESH, unsigned char* EdgeAreas, unsigned char* EdgeDirections) { IplImage* Edge_Areas = cvCreateImage(cvSize(width,height),IPL_DEPTH_8U,1); float g_x, g_y, grad; unsigned char a00, a01, a02; unsigned char a10, a11, a12; unsigned char a20, a21, a22; cvZero(Edge_Areas); for (int i=1; i<height; i++){ for (int j=1; j<width; j++) { a00 = srcImg[(i-1)*width + (j-1)]; a01 = srcImg[(i-1)*width + j]; a02 = srcImg[(i-1)*width + (j+1)]; a10 = srcImg[i*width + (j-1)]; a11 = srcImg[i*width + j]; a12 = srcImg[i*width + (j+1)]; a20 = srcImg[(i+1)*width + (j-1)]; a21 = srcImg[(i+1)*width + j]; a22 = srcImg[(i+1)*width + (j+1)]; if(op == PREWITT_OPERATOR) { //Prewitt算子求梯度 g_y= a20 * (1) + a21 * (1) + a22 * (1)+ (a00 * (-1) + a01 * (-1) + a02 * (-1)); g_x= a02 * (1) + a12 * (1) + a22 * (1)+ a00 * (-1) + a10 * (-1) + a20 * (-1); grad = sqrt(g_x*g_x + g_y*g_y); } else if(op == SOBEL_OPERATOR){ //Sobel算子求梯度 g_y= a20 * (1) + a21 * (2) + a22 * (1)+ (a00 * (-1) + a01 * (-2) + a02 * (-1)); g_x= a02 * (1) + a12 * (2) + a22 * (1)+ a00 * (-1) + a10 * (-2) + a20 * (-1); grad = sqrt(g_x*g_x + g_y*g_y); } else{ //Scharr算子求梯度 g_y= a20 * (3) + a21 * (10) + a22 * (3)+ (a00 * (-3) + a01 * (-10) + a02 * (-3)); g_x= a02 * (3) + a12 * (10) + a22 * (3)+ a00 * (-3) + a10 * (-10) + a20 * (-3); grad = sqrt(g_x*g_x + g_y*g_y); } if (grad > GRADIENT_THRESH) { EdgeAreas[i*width + j] = grad; *(Edge_Areas->imageData + i*Edge_Areas->widthStep + j) = EdgeAreas[i*width + j]; } if (abs(g_x) >= abs(g_y)) { EdgeDirections[i*width + j] = 1; } } } cvShowImage("EdgeAreas",Edge_Areas); cvReleaseImage(&Edge_Areas); } void FindAnchor(unsigned char* EdgeAreas, unsigned char* EdgeDirections, int width, int height, int ANCHOR_THRESH, unsigned char* AnchorMap, vector<Pixel>& anchor) { unsigned char a00, a01, a02; unsigned char a10, a11, a12; unsigned char a20, a21, a22; IplImage* Anchor_Map = cvCreateImage(cvSize(width,height),IPL_DEPTH_8U,1); cvZero(Anchor_Map); int scan_step = 2; Pixel pixel; for (int i=1; i<height; i+=scan_step) { for (int j = 1; j<width; j ++) { a00 = EdgeAreas[(i-1)*width + (j-1)]; a01 = EdgeAreas[(i-1)*width + j]; a02 = EdgeAreas[(i-1)*width + (j+1)]; a10 = EdgeAreas[i*width + (j-1)]; a11 = EdgeAreas[i*width + j]; a12 = EdgeAreas[i*width + (j+1)]; a20 = EdgeAreas[(i+1)*width + (j-1)]; a21 = EdgeAreas[(i+1)*width + j]; a22 = EdgeAreas[(i+1)*width + (j+1)]; unsigned char a = EdgeDirections[i*width + j]; if ((int)a == 1) { //垂直边缘 if ((a11-a10) > ANCHOR_THRESH && (a11-a12) > ANCHOR_THRESH) { AnchorMap[i*width + j] = 255; pixel.r = i; pixel.c = j; pixel.grad = EdgeAreas[i*width + j]; anchor.push_back(pixel); *(Anchor_Map->imageData + i*Anchor_Map->widthStep + j) = AnchorMap[i*width + j]; } } else { //水平边缘 if ((a11-a01) > ANCHOR_THRESH && (a11-a21) > ANCHOR_THRESH) { AnchorMap[i*width + j] = 255; pixel.r = i; pixel.c = j; pixel.grad = EdgeAreas[i*width + j]; anchor.push_back(pixel); *(Anchor_Map->imageData + i*Anchor_Map->widthStep + j) = AnchorMap[i*width + j]; } } } } cvShowImage("AnchorMap",Anchor_Map); cvReleaseImage(&Anchor_Map); } void LinkAnchor(unsigned char* EdgeAreas, unsigned char* EdgeDirections, int width, int height,int GRADIENT_THRESH, unsigned char* AnchorMap, EdgeMap *edgemap) { IplImage* Edge_Map = cvCreateImage(cvSize(width,height),IPL_DEPTH_8U,1); cvZero(Edge_Map); int x, y; bool a, b, c; Pixel* pixels; EdgeSegment* segments; unsigned char *edgeImg; pixels = (Pixel *)malloc(sizeof(Pixel)*width*height); segments = (EdgeSegment *)malloc(sizeof(EdgeSegment)*width*height); edgeImg = (unsigned char *)malloc(sizeof(unsigned char)*width*height); memset(pixels,0x00,sizeof(Pixel)*width*height); memset(segments,0x00,sizeof(EdgeSegment)*width*height); memset(edgeImg,0x00,sizeof(unsigned char)*width*height); for(int y=0; y<height; y++) { for(int x=0; x<width; x++) { while(EdgeAreas[y*width + x] > GRADIENT_THRESH && AnchorMap[y*width + x] == 255 && edgeImg[y*width + x] != 255.0) { if(EdgeDirections[y*width + x] == 0) goto horizontal; if(EdgeDirections[y*width + x] == 1) goto vertical; horizontal: edgeImg[y*width + x] = 255; *(Edge_Map->imageData + y*Edge_Map->widthStep + x) = edgeImg[y*width + x]; //水平向左连接 if (EdgeAre