jashliao 用 VC++ 實現 fanfuhan OpenCV 教學019 ~ opencv-019-使用HSV圖像進行直方圖比較,進而判斷/計算圖像相似度(相似程度)[以圖找圖/以圖搜圖]
jashliao 用 VC++ 實現 fanfuhan OpenCV 教學019 ~ opencv-019-使用HSV圖像進行直方圖比較,進而判斷/計算圖像相似度(相似程度)[以圖找圖/以圖搜圖]
資料來源: https://fanfuhan.github.io/
https://fanfuhan.github.io/2019/03/30/opencv-019/
GITHUB:https://github.com/jash-git/fanfuhan_ML_OpenCV
https://github.com/jash-git/jashliao-implements-FANFUHAN-OPENCV-with-VC
★前言:
★主題:
圖像直方圖比較,就是計算兩幅圖像的直方圖數據,比較兩組數據的相似性,從而得到兩幅圖像之間的相似程度,直方圖比較在早期的CBIR(以圖搜圖)中是應用很常見的技術手段,通常會結合邊緣處理、詞袋等技術一起使用。
OPENCV提供一個用指定的方法比較兩個密集或兩個稀疏直方圖相似度的函數compareHist,其函數相關簡介如下:
double compareHist(InputArray H1, InputArray H2, int method)
該函數適用於1、2、3維密集直方圖,但不適用於高維稀疏直方圖;在這種柱狀圖中,由於存在混疊和採樣問題,非零柱狀圖的坐標會發生輕微的偏移;為了比較這些柱狀圖或更一般的加權點稀疏配置,考慮使用EMD函數;
第一個參數,InputArray H1,待比較的第一個直方圖;
第二個參數,InputArray H2,待比較的第二個直方圖,與第一個直方圖具有相同的大小;
第三個參數,int method,直方圖比較的方法;
HISTCMP_CORREL
HISTCMP_CHISQR ,卡方
HISTCMP_INTERSECT,交叉
HISTCMP_BHATTACHARYYA,Bhattacharyya距離
HISTCMP_HELLINGER,與HISTCMP_BHATTACHARYYA相同
HISTCMP_CHISQR_ALT,變種卡方,這種替代公式經常用於紋理比較
HISTCMP_KL_DIV,交叉熵的K-L散度
★C++
// VC_FANFUHAN_OPENCV019.cpp : 定義主控台應用程式的進入點。 // /* // Debug | x32 通用屬性 | C/C++ | | 一般 | | 其他 Include 目錄 -> C:\opencv\build\include | | 連結器 | |一一般 | | 其他程式庫目錄 -> C:\opencv\build\x64\vc15\lib | | |一輸入 | | 其他相依性 -> opencv_world411d.lib;%(AdditionalDependencies) // Releas | x64 組態屬性 | C/C++ | | 一般 | | 其他 Include 目錄 -> C:\opencv\build\include | | 連結器 | |一般 | | 其他程式庫目錄 -> C:\opencv\build\x64\vc15\lib | | |一輸入 | | 其他相依性 -> opencv_world411.lib;%(AdditionalDependencies) */ #include "stdafx.h" #include <iostream> #include <opencv2/opencv.hpp> #include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> using namespace std; using namespace cv; void showHistogram(InputArray src, cv::String StrTitle); void pause() { printf("Press Enter key to continue..."); fgetc(stdin); } int main() { /* Mat src1 = imread("../../images/test.png"); Mat src2 = imread("../../images/test.png"); */ //* Mat src1 = imread("../../images/left01.jpg"); Mat src2 = imread("../../images/left13.jpg"); //*/ if (src1.empty() || src2.empty()) { cout << "could not load image.." << endl; pause(); return -1; } else { imshow("input_src1", src1); imshow("input_src2", src2); showHistogram(src1, "Histogram_input_src1"); showHistogram(src2, "Histogram_input_src2"); // 一般在HSV色彩空间进行计算 Mat hsv1, hsv2; cvtColor(src1, hsv1, COLOR_BGR2HSV); cvtColor(src2, hsv2, COLOR_BGR2HSV); imshow("input_hsv1", hsv1); imshow("input_hsv2", hsv2); showHistogram(hsv1, "Histogram_input_hsv1"); showHistogram(hsv2, "Histogram_input_hsv2"); int h_bins = 60, s_bins = 64; int histSize[] = { h_bins, s_bins }; float h_ranges[] = { 0, 180 }; float s_ranges[] = { 0, 256 }; const float* ranges[] = { h_ranges, s_ranges }; int channels[] = { 0, 1 }; Mat hist1, hist2; /* void calcHist( const Mat* images, int nimages,const int* channels, InputArray mask,OutputArray hist, int dims, const int* histSize,const float** ranges, bool uniform=true, bool accumulate=false ); 1.輸入的圖像數組 2.輸入數組的個數 3.通道數 4.掩碼 5.直方圖 6.直方圖維度 7.直方圖每個維度的尺寸數組 8.每一維數組的範圍 9.直方圖是否是均勻 10.配置階段不清零 */ calcHist(&hsv1, 1, channels, Mat(), hist1, 2, histSize, ranges);//HSV計算直方圖 calcHist(&hsv2, 1, channels, Mat(), hist2, 2, histSize, ranges); normalize(hist1, hist1, 0, 1, NORM_MINMAX, -1, Mat()); normalize(hist2, hist2, 0, 1, NORM_MINMAX, -1, Mat()); // 比较 double src1_src2_1 = compareHist(hist1, hist2, HISTCMP_CORREL); double src1_src2_2 = compareHist(hist1, hist2, HISTCMP_BHATTACHARYYA); printf("HISTCMP_CORREL : %.2f\n", src1_src2_1); printf("HISTCMP_BHATTACHARYYA : %.2f\n", src1_src2_1); waitKey(0); } return 0; } void showHistogram(InputArray src, cv::String StrTitle) { bool blnGray = false; if (src.channels() == 1) { blnGray = true; } // 三通道/單通道 直方圖 紀錄陣列 vector<Mat> bgr_plane; vector<Mat> gray_plane; // 定义参数变量 const int channels[1] = { 0 }; const int bins[1] = { 256 }; float hranges[2] = { 0, 255 }; const float *ranges[1] = { hranges }; Mat b_hist, g_hist, r_hist, hist; // 计算三通道直方图 /* void calcHist( const Mat* images, int nimages,const int* channels, InputArray mask,OutputArray hist, int dims, const int* histSize,const float** ranges, bool uniform=true, bool accumulate=false ); 1.輸入的圖像數組 2.輸入數組的個數 3.通道數 4.掩碼 5.直方圖 6.直方圖維度 7.直方圖每個維度的尺寸數組 8.每一維數組的範圍 9.直方圖是否是均勻 10.配置階段不清零 */ if (blnGray) { split(src, gray_plane); calcHist(&gray_plane[0], 1, 0, Mat(), hist, 1, bins, ranges); } else { split(src, bgr_plane); calcHist(&bgr_plane[0], 1, 0, Mat(), b_hist, 1, bins, ranges); calcHist(&bgr_plane[1], 1, 0, Mat(), g_hist, 1, bins, ranges); calcHist(&bgr_plane[2], 1, 0, Mat(), r_hist, 1, bins, ranges); } /* * 显示直方图 */ int hist_w = 512; int hist_h = 400; int bin_w = cvRound((double)hist_w / bins[0]); Mat histImage = Mat::zeros(hist_h, hist_w, CV_8UC3); // 归一化直方图数据 if (blnGray) { normalize(hist, hist, 0, histImage.rows, NORM_MINMAX, -1); } else { normalize(b_hist, b_hist, 0, histImage.rows, NORM_MINMAX, -1); normalize(g_hist, g_hist, 0, histImage.rows, NORM_MINMAX, -1); normalize(r_hist, r_hist, 0, histImage.rows, NORM_MINMAX, -1); } // 绘制直方图曲线 for (int i = 1; i < bins[0]; ++i) { if (blnGray) { line(histImage, Point(bin_w * (i - 1), hist_h - cvRound(hist.at<float>(i - 1))), Point(bin_w * (i), hist_h - cvRound(hist.at<float>(i))), Scalar(255, 255, 255), 2, 8, 0); } else { line(histImage, Point(bin_w * (i - 1), hist_h - cvRound(b_hist.at<float>(i - 1))), Point(bin_w * (i), hist_h - cvRound(b_hist.at<float>(i))), Scalar(255, 0, 0), 2, 8, 0); line(histImage, Point(bin_w * (i - 1), hist_h - cvRound(g_hist.at<float>(i - 1))), Point(bin_w * (i), hist_h - cvRound(g_hist.at<float>(i))), Scalar(0, 255, 0), 2, 8, 0); line(histImage, Point(bin_w * (i - 1), hist_h - cvRound(r_hist.at<float>(i - 1))), Point(bin_w * (i), hist_h - cvRound(r_hist.at<float>(i))), Scalar(0, 0, 255), 2, 8, 0); } } imshow(StrTitle, histImage); } /* HSV (HSV顏色模型) https://baike.baidu.hk/item/HSV/547122 HSV(Hue, Saturation, Value)是根據顏色的直觀特性由A. R. Smith在1978年創建的一種顏色空間, 也稱六角錐體模型(Hexcone Model)。 色調H : 用角度度量,取值范圍為0°~360°,從紅色開始按逆時針方向計算,紅色為0°,綠色為120°,藍色為240°。它們的補色是:黃色為60°,青色為180°,紫色為300°; 飽和度S : 表示顏色接近光譜色的程度。一種顏色,可以看成是某種光譜色與白色混合的結果。其中光譜色所占的比例愈大,顏色接近光譜色的程度就愈高,顏色的飽和度也就愈高。飽和度高,顏色則深而艷。光譜色的白光成分為0,飽和度達到最高。通常取值范圍為0%~100%,值越大,顏色越飽和。 明度V : 表示顏色明亮的程度,對於光源色,明度值與發光體的光亮度有關;對於物體色,此值和物體的透射比或反射比有關。通常取值范圍為0%(黑)到100%(白)。 RGB和CMY顏色模型都是面向硬件的,而HSV(Hue Saturation Value)顏色模型是面向用戶的。 HSV模型的三維表示從RGB立方體演化而來。設想從RGB沿立方體對角線的白色頂點向黑色頂點觀察,就可以看到立方體的六邊形外形。六邊形邊界表示色彩,水平軸表示純度,明度沿垂直軸測量。 RGB轉化到HSV的算法: max=max(R,G,B); min=min(R,G,B); V=max(R,G,B); S=(max-min)/max; if (R = max) H =(G-B)/(max-min)* 60; if (G = max) H = 120+(B-R)/(max-min)* 60; if (B = max) H = 240 +(R-G)/(max-min)* 60; if (H < 0) H = H+ 360; HSV轉化到RGB的算法: if (s = 0) R=G=B=V; else H /= 60; i = INTEGER(H); f = H - i; a = V * ( 1 - s ); b = V * ( 1 - s * f ); c = V * ( 1 - s * (1 - f ) ); switch(i) case 0: R = V; G = c; B = a; case 1: R = b; G = v; B = a; case 2: R = a; G = v; B = c; case 3: R = a; G = b; B = v; case 4: R = c; G = a; B = v; case 5: R = v; G = a; B = b; */
★Python
import cv2 as cv import numpy as np src1 = cv.imread("D:/vcprojects/images/m1.png") src2 = cv.imread("D:/vcprojects/images/m2.png") src3 = cv.imread("D:/vcprojects/images/flower.png") src4 = cv.imread("D:/vcprojects/images/wm_test.png") cv.imshow("input1", src1) cv.imshow("input2", src2) cv.imshow("input3", src3) cv.imshow("input4", src4) hsv1 = cv.cvtColor(src1, cv.COLOR_BGR2HSV) hsv2 = cv.cvtColor(src2, cv.COLOR_BGR2HSV) hsv3 = cv.cvtColor(src3, cv.COLOR_BGR2HSV) hsv4 = cv.cvtColor(src4, cv.COLOR_BGR2HSV) hist1 = cv.calcHist([hsv1], [0, 1], None, [60, 64], [0, 180, 0, 256]) hist2 = cv.calcHist([hsv2], [0, 1], None, [60, 64], [0, 180, 0, 256]) hist3 = cv.calcHist([hsv3], [0, 1], None, [60, 64], [0, 180, 0, 256]) hist4 = cv.calcHist([hsv4], [0, 1], None, [60, 64], [0, 180, 0, 256]) cv.normalize(hist1, hist1, 0, 1.0, cv.NORM_MINMAX, dtype=np.float32) cv.normalize(hist2, hist2, 0, 1.0, cv.NORM_MINMAX) cv.normalize(hist3, hist3, 0, 1.0, cv.NORM_MINMAX) cv.normalize(hist4, hist4, 0, 1.0, cv.NORM_MINMAX) methods = [cv.HISTCMP_CORREL, cv.HISTCMP_CHISQR, cv.HISTCMP_INTERSECT, cv.HISTCMP_BHATTACHARYYA] str_method = "" for method in methods: src1_src2 = cv.compareHist(hist1, hist2, method) src3_src4 = cv.compareHist(hist3, hist4, method) if method == cv.HISTCMP_CORREL: str_method = "Correlation" if method == cv.HISTCMP_CHISQR: str_method = "Chi-square" if method == cv.HISTCMP_INTERSECT: str_method = "Intersection" if method == cv.HISTCMP_BHATTACHARYYA: str_method = "Bhattacharyya" print("%s src1_src2 = %.2f, src3_src4 = %.2f"%(str_method, src1_src2, src3_src4)) cv.waitKey(0) cv.destroyAllWindows()
★結果圖:
★延伸說明/重點回顧: