【OpenCV】使用floodfill()實現PhotoShop魔棒功能

在OpenCV中看到一個很有意思的函數：floodfill()

使用給定顏色填充一個聯通的地區

C++: int floodFill(InputOutputArray image, Point seedPoint, Scalar newVal, Rect* rect=0, Scalar loDiff=Scalar(), Scalar upDiff=Scalar(), int flags=4 )

一個簡單的例子：

#include "opencv2/imgproc/imgproc.hpp"#include "opencv2/highgui/highgui.hpp"#include <iostream>using namespace cv;using namespace std;//floodfill()//Fills a connected component with the given color.static void help(){cout << "\nThis program demonstrated the floodFill() function\n""Call:\n""./ffilldemo [image_name -- Default: fruits.jpg]\n" << endl;cout << "Hot keys: \n""\tESC - quit the program\n""\tc - switch color/grayscale mode\n""\tm - switch mask mode\n""\tr - restore the original image\n""\ts - use null-range floodfill\n""\tf - use gradient floodfill with fixed(absolute) range\n""\tg - use gradient floodfill with floating(relative) range\n""\t4 - use 4-connectivity mode\n""\t8 - use 8-connectivity mode\n" << endl;}Mat image0, image, gray, mask;int ffillMode = 1;int loDiff = 20, upDiff = 20;int connectivity = 4;int isColor = true;bool useMask = false;int newMaskVal = 255;static void onMouse( int event, int x, int y, int, void* ){if( event != CV_EVENT_LBUTTONDOWN )return;Point seed = Point(x,y);int lo = ffillMode == 0 ? 0 : loDiff;int up = ffillMode == 0 ? 0 : upDiff;int flags = connectivity + (newMaskVal << 8) +(ffillMode == 1 ? CV_FLOODFILL_FIXED_RANGE : 0);int b = (unsigned)theRNG() & 255;int g = (unsigned)theRNG() & 255;int r = (unsigned)theRNG() & 255;Rect ccomp;Scalar newVal = isColor ? Scalar(b, g, r) : Scalar(r*0.299 + g*0.587 + b*0.114);Mat dst = isColor ? image : gray;int area;if( useMask ){threshold(mask, mask, 1, 128, CV_THRESH_BINARY);area = floodFill(dst, mask, seed, newVal, &ccomp, Scalar(lo, lo, lo),Scalar(up, up, up), flags);imshow( "mask", mask );}else{area = floodFill(dst, seed, newVal, &ccomp, Scalar(lo, lo, lo),Scalar(up, up, up), flags);}imshow("image", dst);cout << area << " pixels were repainted\n";}int main( ){char* filename="0.png";image0 = imread(filename, 1);if( image0.empty() ){cout << "Image empty. Usage: ffilldemo <image_name>\n";return 0;}help();image0.copyTo(image);cvtColor(image0, gray, CV_BGR2GRAY);mask.create(image0.rows+2, image0.cols+2, CV_8UC1);namedWindow( "image", 0 );createTrackbar( "lo_diff", "image", &loDiff, 255, 0 );createTrackbar( "up_diff", "image", &upDiff, 255, 0 );setMouseCallback( "image", onMouse, 0 );for(;;){imshow("image", isColor ? image : gray);int c = waitKey(0);if( (c & 255) == 27 ){cout << "Exiting ...\n";break;}switch( (char)c ){case 'c':if( isColor ){cout << "Grayscale mode is set\n";cvtColor(image0, gray, CV_BGR2GRAY);mask = Scalar::all(0);isColor = false;}else{cout << "Color mode is set\n";image0.copyTo(image);mask = Scalar::all(0);isColor = true;}break;case 'm':if( useMask ){destroyWindow( "mask" );useMask = false;}else{namedWindow( "mask", 0 );mask = Scalar::all(0);imshow("mask", mask);useMask = true;}break;case 'r':cout << "Original image is restored\n";image0.copyTo(image);cvtColor(image, gray, CV_BGR2GRAY);mask = Scalar::all(0);break;case 's':cout << "Simple floodfill mode is set\n";ffillMode = 0;break;case 'f':cout << "Fixed Range floodfill mode is set\n";ffillMode = 1;break;case 'g':cout << "Gradient (floating range) floodfill mode is set\n";ffillMode = 2;break;case '4':cout << "4-connectivity mode is set\n";connectivity = 4;break;case '8':cout << "8-connectivity mode is set\n";connectivity = 8;break;}}return 0;}

點擊表徵圖改變映像中的連圖地區的顏色：

（轉載請註明作者和出處：http://blog.csdn.net/xiaowei_cqu 未經允許請勿用於商業用途）