【转】OpenCV图像处理 图像的点运算 ( 灰度直方图 )

[code]intmain()

{

Matimg=imread("lena.jpg",CV_LOAD_IMAGE_GRAYSCALE);

Mat*arrays=&img;

intnarrays=1;

intchannels[]={0};

InputArraymask=noArray();

Mathist;

intdims=1;

inthistSize[]={256};

floathranges[]={0.0,255.0};

constfloat*ranges[]={hranges};

//调用calcHist计算直方图,结果存放在hist中

calcHist(arrays,narrays,channels,mask,hist,dims,histSize,ranges);

//调用一个我自己写的简单的函数用于获取一张显示直方图数据的图片,

//输入参数为直方图数据hist和期望得到的图片的尺寸

MathistImg=ggicci::getHistogram1DImage(hist,Size(600,420));

imshow("lenagrayimagehistogram",histImg);

waitKey();

}

Matggicci::getHistogram1DImage(constMat&hist,SizeimgSize)

{

MathistImg(imgSize,CV_8UC3);

intPadding=10;

intW=imgSize.width-2*Padding;

intH=imgSize.height-2*Padding;

double_max;

minMaxLoc(hist,NULL,&_max);

doublePer=(double)H/_max;

constPointOrig(Padding,imgSize.height-Padding);

intbin=W/(hist.rows+2);

//画方柱

for(inti=1;i<=hist.rows;i++)

{

PointpBottom(Orig.x+i*bin,Orig.y);

PointpTop(pBottom.x,pBottom.y-Per*hist.at<float>(i-1));

line(histImg,pBottom,pTop,Scalar(255,0,0),bin);

}

//画3条红线标明区域

line(histImg,Point(Orig.x+bin,Orig.y-H),Point(Orig.x+hist.rows*bin,Orig.y-H),Scalar(0,0,255),1);

line(histImg,Point(Orig.x+bin,Orig.y),Point(Orig.x+bin,Orig.y-H),Scalar(0,0,255),1);

line(histImg,Point(Orig.x+hist.rows*bin,Orig.y),Point(Orig.x+hist.rows*bin,Orig.y-H),Scalar(0,0,255),1);

drawArrow(histImg,Orig,Orig+Point(W,0),10,30,Scalar::all(0),2);

drawArrow(histImg,Orig,Orig-Point(0,H),10,30,Scalar::all(0),2);

returnhistImg;

}