Create an antialiased 2X copy of the image.
Image Downsampled2X(void) const;
an antialiased copy of the current image.
Downsampled2X creates an antialisased copy of the current image by downsampling the pixels matrix. 2*2 pixels are used to create one in the new image. This function is not working with JPG format. The output format is X8R8G8B8.