Ok. Thanks for the responses and I'll try to answer the best I can.
I am making a freeware scenery for FSX. I'm using google sketchup models(with permission of course) for this project (16 of them). This process is making the night textures for these models.
I first open the normal (Daytime) file
![Image](http://i609.photobucket.com/albums/tt171/HootyHooGLB/brickwork_zps26c46e61.jpg)
I then go Colors -> Levels -> Output level -> 25 (I have this set as a preset "Nighttime" so I don't have to adjust the slide each time.
I then select Bucket fill, set the mode to Overlay and set the color to 255, 245, 212
I then double click on the image to get this result
![Image](http://i609.photobucket.com/albums/tt171/HootyHooGLB/brickwork_LM_zps2c07d44a.jpg)
I then export the file out with the same file name but add _LM to the end so that the model knows there is a night texture.
These textures are various shapes and sizes if that helps any.
That's it. After I posted last night I did another 200 of these manually and I'm just getting started. Some of these models have 300 textures that need made and I think I have 5 of the 16 models finished. I just figured, or hoped there was an easier way. I had also hoped that since the process is the same for each texture in a directory that somehow I could batch that folder. That's what led me here.
I hope I explained this well enough. If you have any other questions I will answer them the best I can.
Thanks again
-Kevin