Ground Plane Image Contrast Improvement

edit

I have been trying to add this image into the gazebo for the drone to scan. I followed this tutorial (https://magiccvs.byu.edu/wiki/#!gazeb...), but the image inside the gazebo appeared to be darker than the original. I've tried changing the brightness of the sun and the ambient, diffuse, specular variables. However, this is the best I managed to get. Does anyone have a similar issue or know ways to solve this. Thanks.

screenshot of how the image looks like from the gazebo and the camera

screenshot of the original image