#include <cxcore.h>
#include <cv.h>
#include <highgui.h>
#pragma comment(lib,"cv.lib")
#pragma comment(lib,"cxcore.lib")
#pragma comment(lib,"highgui.lib")

void FlipV(unsigned char *out, unsigned char *in, int inHeight, int inWidth, int inChannel);

int main(){
   IplImage *in, *out;
   in = cvLoadImage("./image640.bmp", 1);
   out = cvCreateImage(cvSize((int)(in->width), (int)(in->height)), in->depth, in->nChannels);

   FlipV((unsigned char*)out->imageData, (unsigned char*)in->imageData, in->height, in->width, in->nChannels);

   cvNamedWindow("in", 1);
   cvShowImage("in", in);
   cvNamedWindow("out", 1);
   cvShowImage("out", out);
   cvWaitKey(-1);

   cvDestroyWindow("in");
   cvDestroyWindow("out");
   cvReleaseImage(&in);
   cvReleaseImage(&out);
   return 0;
}

/*
in : 横は4バイト
*/
void FlipV(unsigned char *out, unsigned char *in, int inHeight, int inWidth, int inChannel){
   int widthStep;
   int i, j;

   // OpenCVで使用する画像データの横幅は4バイト区切りのため調整
   widthStep = inWidth * inChannel;
   if( (widthStep % 4) != 0){
      widthStep = widthStep + (4 - widthStep %4);
   }

   // ループ中にif文を書くと遅いためループ前にビット数の条件分岐
   switch(inChannel){
      case 1:
         // 8bit画像
         for(i = 0; i < inHeight; ++i){
            for(j = 0; j < inWidth; ++j){
               out[i * widthStep + j] = in[(inHeight - i - 1) * widthStep + j];
            }
         }
         break;
      case 3:
         // 24bit画像
         for(i = 0; i < inHeight; ++i){
            for(j = 0; j < inWidth; ++j){
               out[i * widthStep + j * 3] = in[(inHeight - i - 1) * widthStep + j * 3];
               out[i * widthStep + j * 3 + 1] = in[(inHeight - i - 1) * widthStep + j * 3 + 1];
               out[i * widthStep + j * 3 + 2] = in[(inHeight - i - 1) * widthStep + j * 3 + 2];
            }
         }
         break;
      case 4:
         // 32bit画像
         for(i = 0; i < inHeight; ++i){
            for(j = 0; j < inWidth; ++j){
               out[i * widthStep + j * 4] = in[(inHeight - i - 1) * widthStep + j * 4];
               out[i * widthStep + j * 4 + 1] = in[(inHeight - i - 1) * widthStep + j * 4 + 1];
               out[i * widthStep + j * 4 + 2] = in[(inHeight - i - 1) * widthStep + j * 4 + 2];
               out[i * widthStep + j * 4 + 3] = in[(inHeight - i - 1) * widthStep + j * 4 + 3];
            }
         }
         break;
      default:
         break;
   }
}