Get an Image of a Flex Environment

I have been looking for a way to get an image of the Flex environment that is being rendered.

I have found a way to get an image of the rendered environment by using the glReadPixels method via openGL, but that requires a window of the flex program to be open and looks more like a screenshot.

Is there a way to get an image of the flex environment without opening a window of the Flex Program? Something which I could run solely on the command prompt, and wouldn’t need to actually display the program?