c – CImg错误：’gm.exe’未被识别为内部或外部命令,

我写的基本代码是(请原谅任何语法错误,作为我的代码的复制部分)：

#include "CImg.h"// Include CImg library header.
#include <iostream>

using namespace cimg_library;
using namespace std;

const int screen_size = 800;

//-------------------------------------------------------------------------------
//  Main procedure
//-------------------------------------------------------------------------------
int main()
{

CImg<unsigned char> img(screen_size,screen_size,1,3,20);
CImgDisplay disp(img,"CImg Tutorial");   
//Some drawing using img.draw_circle( 10,10,60,RED);
img.save("result.jpg"); // save the image    
return 0;   
}

但我无法运行我的程序,因为它说：

Invalid Parameter - 100%
'gm.exe' is not recognized as an internal or external command,operable program or batch file.

This application has requested the Runtime to terminate it in an unusual way.
please contact the application's support team for more information.

[CImg] *** CImgIOException *** [instance(800,800,02150020,non-shared)] CImg<unsigned char>::save_other() : Failed to save file 'result.jpg'. Format is not natively supported,and no external commands succeeded.
terminate called after throwing an instance of 'cimg_library::CImgIOException'
  what():  [instance(800,and no external commands succeeded.

虽然我可以看到图像,但我无法保存.
谷歌搜索后,我发现人们说要安装ImageMagick,我已经安装了它但没有帮助.
一些论坛说要针对libjpeg,libpng,libmagick进行编译.但我不知道如何编译这些库.
我正在使用Eclipse CDT插件来编写C项目.
请帮我 .