IplImage *img = cvLoadImage("C:\\Users\\Administrator\\Desktop\\3838.jpg");
int nw = img->width;
int nh = img->height;

void Ctry::OnTryTyr1()
{
	//TODO:  在此新增命令處理程式程式碼  
	double times = 0.8;          //比例因子  
	int nWidth =int( times * (img->width));
	int nHeight =int( times * (img->height));
	IplImage *dst = cvCreateImage(cvSize(nWidth, nHeight), 8, 3);

	CvScalar pixel1;
	for (int i = 0; i < dst->width; i++)
	{
		for (int j = 0; j < dst->height; j++)
		{
			if (int(i * 1 / times) < img->width && int(j * 1 / times) < img->height)
			{
				pixel1 = InterpBilinear((i * 1 / times), (j * 1 / times ));
				cvSet2D(dst, j, i, pixel1);
			}
			else
			{
				cvSet2D(dst, j, i, RGB(0, 0, 0, ));
			}
		}
	}
	cvSaveImage("C:\\Users\\Administrator\\Desktop\\InterpBilinear.jpg", dst);
	cvNamedWindow(" dst", CV_WINDOW_AUTOSIZE);
	cvShowImage(" dst", dst);
	cvNamedWindow("img", CV_WINDOW_AUTOSIZE);
	cvShowImage("img", img);
	cvWaitKey(0);

	cvReleaseImage(&img);
	cvReleaseImage(&dst);
	cvDestroyWindow(" dst");
	cvDestroyWindow("img");
}

CvScalar Ctry::InterpBilinear(double x, double y)
{
	//4個鄰近點的座標（i1,j1）,（i2,j1）,（i1,j2）,（i2,j2）
	int x1, x2;
	int y1, y2;
	//4個最鄰近畫素值
	CvScalar f1, f2, f3, f4;
	//二個插值中間值
	CvScalar f12, f34;
	CvScalar pixel;
	double epsilon = 0.0001;
	//計算四個最鄰近畫素的座標
	x1 = int(x);
	x2 = x1 + 1;
	y1 = int(y);
	y2 = y1 + 1;

	if ((x<0) || (x>nw - 1) || (y<0) || (y>nh - 1))
	{
		//要計算的點不在原圖範圍內
		MessageBox(NULL, "超過圖片大小", "錯誤", MB_OK | MB_ICONERROR);
		return 0;
	}
	else
	{
		if (fabs(x - nw + 1 )<= epsilon)
		{
			//要計算的點在影象的右邊緣上
			if (fabs(y - nh + 1) <= epsilon)
			{
				//要計算的元素恰好是影象最右下角的那一個元素，直接返回該點的畫素值
				f1 = cvGet2D(img, y1, x1);
				return f1;
			}
			else
			{
				//在影象右邊緣且不是最後一點，直接一次插值即可
				f1 = cvGet2D(img, y1, x1);
				f3 = cvGet2D(img, y1, x2);
				pixel.val[0] = f1.val[0] + (y - y1)*(f3.val[0] - f1.val[0]);
				pixel.val[1] = f1.val[1] + (y - y1)*(f3.val[1] - f1.val[1]);
				pixel.val[2] = f1.val[2] + (y - y1)*(f3.val[2] - f1.val[2]);
				return pixel;
			}
		}
		else if (fabs(y - nh + 1) <= epsilon)
		{
			//要計算的點在影象的下邊緣上且不是最後一點，直接一次插值即可
			f1 = cvGet2D(img, y1, x1);
			f2 = cvGet2D(img, y2, x1);
			pixel.val[0] = f1.val[0] + (x - x1)*(f2.val[0] - f1.val[0]);
			pixel.val[1] = f1.val[1] + (x - x1)*(f2.val[1] - f1.val[1]);
			pixel.val[2] = f1.val[2] + (x - x1)*(f2.val[2] - f1.val[2]);
			return pixel;
		}
		else
		{
			//計算4個最鄰近畫素值
			f1 = cvGet2D(img, y1, x1);
			f2 = cvGet2D(img, y2, x1);
			f3 = cvGet2D(img, y1, x2);
			f4 = cvGet2D(img, y2, x2);
			//插值1
			f12.val[0] = f1.val[0] + (x - x1)*(f2.val[0] - f1.val[0]);
			f12.val[1] = f1.val[1] + (x - x1)*(f2.val[1] - f1.val[1]);
			f12.val[2] = f1.val[2] + (x - x1)*(f2.val[2] - f1.val[2]);
			//插值2
			f34.val[0] = f3.val[0] + (x - x1)*(f4.val[0] - f3.val[0]);
			f34.val[1] = f3.val[1] + (x - x1)*(f4.val[1] - f3.val[1]);
			f34.val[2] = f3.val[2] + (x - x1)*(f4.val[2] - f3.val[2]);
			//插值3
			pixel.val[0] = f12.val[0] + (y - y1)*(f34.val[0] - f12.val[0]);
			pixel.val[1] = f12.val[1] + (y - y1)*(f34.val[1] - f12.val[1]);
			pixel.val[2] = f12.val[2] + (y - y1)*(f34.val[2] - f12.val[2]);

			return pixel;
		}
	}
}