CImg: open an image file

CImg provides several constructors for cimg_library::CImg type objects.

[code lang="c"] std::string strFile = "lena.bmp";

cimg_library::CImg<unsigned char> img1(strFile.c_str());

cimg_library::CImg<unsigned char> img2;
img2 = cimg_library::CImg<unsigned char>(strFile.c_str());

[/code]