opencv 图像载入、显示和输出

#include <opencv2/core/core.hpp>
#include <opencv2\highgui\highgui.hpp>

using namespace cv;

int main()
{
	//图像载入和显示
	Mat girl = imread("girl.jpg");
	namedWindow("【1】动漫图");
	imshow("【1】动漫图", girl);
	//waitKey(0);

	//初级图像融合

	Mat image = imread("dota.jpg");
	Mat logo = imread("dota_logo.jpg");
	namedWindow("【2】原画图");
	imshow("【2】原画图", image);
	namedWindow("【3】logo图");
	imshow("【3】logo图",logo);
	//waitKey(0);

	////找出Roi
	////方法一
	Mat imageROI;
	imageROI = image(Rect(800, 350, logo.cols, logo.rows));

	////方法二
	////imageROI = image(Range(350, 350 + logo.rows), Range(800, 800 + logo.cols));

	addWeighted(imageROI, 0.5, logo, 0.3, 0., imageROI);

	////显示结果
	namedWindow("效果图");
	imshow("效果图", image);
	

	//图像输出
	imwrite("生成的图片.bmp", image);

	waitKey(0);

	return 0;
}

图像输出一开始设置为jpg格式，总是报错，改为bmp格式则正确