Quote Originally Posted by RobA View Post
Post 7: Create the sea, continued.

Now we want to stretch out the colours in the “Sea” layer across the entire black to white range. With the sea layer selected, auto normalize the image (Colors->Auto->Normalize). The histogram will now have little gaps in it. As the greys have all been spread out. To fix this, select the non-transparent area (by clicking on the “Sea” layer and selecting “Alpha to Selection”. Invert the selection (Select->Invert) and fill the area with white. Remove the selection (Select->None) and apply a 20px Gaussian blur.
During this part of the process, I cannot fill the transparent area with white. I will attach a photo of my map. I would attach a gimp file if I knew how to haha.Click image for larger version. 

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