C語言實現直方圖均衡化
直方圖均衡化部分是用c語言寫的,最後用opencv顯示原圖像,處理後圖像以及原圖和處理後圖的灰度直方圖。
雖然做出來瞭,均衡化效果還可以,但不知道為什麼處理後圖像中有三條白線,真心搞不懂,有看出來問題的大神麻煩留言告訴我,謝謝。
(終於知道哪出問題瞭,原來是每行字節數求錯瞭,改為LineByte=(width*8/8+3)/4*4;即可。)
下面是代碼:
#include "stdafx.h" #include<stdio.h> #include<windows.h> #include<opencv2\highgui\highgui.hpp> #include<opencv2\core\core.hpp> #include<cv.h> int main(void) { int width;//圖像寬度 int height;//圖像高度 RGBQUAD *pColorTable; unsigned char *pBmpBuf,*pBmpBuf1; BITMAPFILEHEADER bfhead; BITMAPINFOHEADER bihead; FILE *fp1=fopen("e:\\picture\\dog.bmp","rb"); if(fp1==0) return 0; fread(&bfhead,14,1,fp1); fread(&bihead,40,1,fp1); width=bihead.biWidth; height=bihead.biHeight; pColorTable=new RGBQUAD[256]; fread(pColorTable,4,256,fp1); int LineByte=0; LineByte=(width*1/4+1)*4; <span style="white-space:pre"> </span>//LineByte=(width*8/8+3)/4*4; pBmpBuf = new unsigned char[LineByte*height]; fread(pBmpBuf,LineByte*height,1,fp1); fclose(fp1); pBmpBuf1=new unsigned char[LineByte*height]; //用於存儲均值化後的圖像數據 //統計每個灰度級像素點的個數 int N[256]={0}; for(int i=0;i<height;i++) for(int j=0;j<width;j++) { unsigned char *pb1,*pb2; pb1=pBmpBuf+i*LineByte+j; N[*pb1]++; pb2=pBmpBuf1+i*LineByte+j; *pb2=*pb1; } /*for(int i=0;i<256;i++ ) printf("%d ",N[i]);*/ //統計最小與最大灰度值 int minGrayValue=255; int maxGrayValue=0; for(int i=0;i<height;i++) for(int j=0;j<width;j++) { unsigned char *pb; pb=pBmpBuf+i*LineByte+j; if(*pb>maxGrayValue) maxGrayValue=*pb; else if(*pb<minGrayValue) minGrayValue=*pb; } printf("%d ,%d\n",minGrayValue,maxGrayValue);//輸出最大與最小灰度值 int x=maxGrayValue-minGrayValue+1; float *p; p=new float[x]; for(int i=0;i<x;i++) { *(p+i)=(float)N[i]/(float)(width*height); //*(p+i)中存放的是灰度級為i的像素在整幅圖像中出現 //的概率(即*(p+i)i=0,1,2,3...中存放的就是這幅圖像歸一化後的直方圖) } float *c; c=new float[x]; //定義c,用來存放累積的歸一化直方圖 for(int i=0;i<x;i++) //對c進行初始化 { *(c+i)=0; } for(int i=0;i<x;i++) { for(int j=0;j<=i;j++) { *(c+i)+=*(p+j); } } for(int i=0;i<height;i++) for(int j=0;j<width;j++) { unsigned char *pb; pb=pBmpBuf1+i*LineByte+j; *pb=*(c+*pb)*(maxGrayValue-minGrayValue)+minGrayValue; } FILE *fp2=fopen("junhenghua.bmp","wb"); fwrite(&bfhead,14,1,fp2); fwrite(&bihead,40,1,fp2); fwrite(pColorTable,4,256,fp2); fwrite(pBmpBuf1,LineByte*height,1,fp2); fclose(fp2); //顯示原圖與處理後的圖像 IplImage *src1=cvLoadImage("e:\\picture\\dog.bmp"); IplImage *src2=cvLoadImage("junhenghua.bmp"); cvNamedWindow("原圖"); cvNamedWindow("處理後圖"); cvShowImage("原圖",src1); cvShowImage("處理後圖",src2); //顯示原圖像與處理後圖像的灰度直方圖 int size=256; float range[]={0,255}; float *ranges[]={range}; CvHistogram *hist1=cvCreateHist(1,&size, CV_HIST_ARRAY,ranges,1);//創建一維直方圖, CvHistogram *hist2=cvCreateHist(1,&size, CV_HIST_ARRAY,ranges,1); IplImage* gray1=cvCreateImage(cvGetSize(src1),8,1); IplImage* gray2=cvCreateImage(cvGetSize(src2),8,1); cvCvtColor(src1,gray1,CV_BGR2GRAY); cvCvtColor(src2,gray2,CV_BGR2GRAY); //vCvtColor(...),是Opencv裡的顏色空間轉換函數,可以實現RGB顏色向HSV,HSI等顏色空間的轉換,也可以轉換為灰度圖像。 //參數CV_RGB2GRAY是RGB到gray, //參數CV_GRAY2RGB是gray到RGB cvCalcHist(&gray1,hist1,0,0);//統計圖像在[0 255]像素的均勻分佈,將統計結果存在結構體中 cvCalcHist(&gray2,hist2,0,0); //draw histogram----- //統計直方圖中的最大直方塊 float histMax1=0,histMax2=0; cvGetMinMaxHistValue(hist1,0,&histMax1,0); cvGetMinMaxHistValue(hist2,0,&histMax2,0); //創建一張一維直方圖的“圖”,橫坐標為灰度級,縱坐標為像素個數 IplImage *grayHist1=cvCreateImage(cvSize(256*2,64*2),8,1); IplImage *grayHist2=cvCreateImage(cvSize(256*2,64*2),8,1); cvZero(grayHist1); cvZero(grayHist2); //分別將每個直方塊的值繪制到圖中 for(int i=0;i<255;i++) { float histValue=cvQueryHistValue_1D(hist1,i); float nextValue=cvQueryHistValue_1D(hist1,i+1); //計算直方塊4個點的值 CvPoint pt1=cvPoint(i*2,64*2); CvPoint pt2=cvPoint((i+1)*2,64*2); CvPoint pt3=cvPoint((i+1)*2,(64-(nextValue/histMax1)*64)*2); //nextValue/histMax是將i級像素點個數歸一到0~1,在*64是使其高對在0~64之間 //由於opencv圖像是以左上角為坐標原點,向右為x軸,向下時y軸,而顯示的直方圖是向上增長的,所以用64減,將其倒過來顯示 CvPoint pt4=cvPoint(i*2, (64-(histValue/histMax1)*64)*2); int ptNum=5; CvPoint pt[5]; pt[0]=pt1; pt[1]=pt2; pt[2]=pt3; pt[3]=pt4; pt[4]=pt1; cvFillConvexPoly(grayHist1,pt,ptNum,cvScalar(255)); //填充直方塊 } for(int i=0;i<255;i++) { float histValue=cvQueryHistValue_1D(hist2,i); float nextValue=cvQueryHistValue_1D(hist2,i+1); //計算直方塊4個點的值 CvPoint pt1=cvPoint(i*2,64*2); CvPoint pt2=cvPoint((i+1)*2,64*2); CvPoint pt3=cvPoint((i+1)*2,(64-(nextValue/histMax2)*64)*2); //nextValue/histMax是將i級像素點個數歸一到0~1,在*64是使其高對在0~64之間 //由於opencv圖像是以左上角為坐標原點,向右為x軸,向下時y軸,而顯示的直方圖是向上增長的,所以用64減,將其倒過來顯示 CvPoint pt4=cvPoint(i*2, (64-(histValue/histMax2)*64)*2); int ptNum=5; CvPoint pt[5]; pt[0]=pt1; pt[1]=pt2; pt[2]=pt3; pt[3]=pt4; pt[4]=pt1; cvFillConvexPoly(grayHist2,pt,ptNum,cvScalar(255)); //填充直方塊 } cvNamedWindow("grayHistogram1"); cvNamedWindow("grayHistogram2"); cvShowImage("grayHistogram1",grayHist1); cvShowImage("grayHistogram2",grayHist2); cvWaitKey(0); system("pause"); return 0; }
原圖:
處理後圖:
原圖直方圖:
均衡化後直方圖:
以上就是本文的全部內容,希望對大傢的學習有所幫助,也希望大傢多多支持WalkonNet。