// ************************* 程序 18-1 ****************************
/*** 程序功能：
    訪問圖像像素

// ***************************************************************/


///*

#include "cv.h"
#include "highgui.h"

int main ()
{
    IplImage *img = 0;
    img = cvLoadImage ( "test.jpg", 1 );
    int x, y;
    for ( x = 0; x < 200; x ++ )
    {
        for ( y = 0; y < 100; y ++ )
        {
            ( ( uchar * ) ( img->imageData + img->widthStep * y ) )[x * 3] -= 50;
            //藍通道
            ( ( uchar * ) ( img->imageData + img->widthStep * y ) )[x * 3 + 1] -= 50;
            //綠通道
            ( ( uchar * ) ( img->imageData + img->widthStep * y ) )[x * 3 + 2] -= 50;
            //紅通道
        }
    }
    //對左上角(100×200)的像素點每通道像素值減去50.

    cvNamedWindow ( "dst", 1 );
    cvShowImage ( "dst", img );
    cvWaitKey ( 0 );
    return 0;
}


//*/