Transparent TGAs not displaying correctly

[Storyyeller]

I thought that I could remove the awful edge artifacts in my loadscreen and reduce the map size by splitting it into two seperate textures: one for the sky, and a transparent one for the foreground.
However, it won't show up correctly. No matter what I try, it always has a weird border at the edges. I tried flattening it, but that didn't help either.

Anyway, here are the background and foreground images I am using (zoomed in), and how it is supposed to look.

And here is how it actually looks

What am I doing wrong? How can I fix it?

 

[dimitri231]

Try increasing the image size in photoshop without making the image with weird borders,
splitting the image isnt a good idea, put everything in one and then use photoshop.

 

[Storyyeller]

What do you mean by increasing the size without making the image with weird borders? Could you elaborate please? I'm confused

I tried putting the image in a single texture, but I couldn't find a way to get good quality with a small filesize.

 

[dimitri231]

Good Quality with small filesize isnt possible.U dont need good quality since they are pyramids.

 

[Storyyeller]

So you're saying it is impossible to use transparent images in Warcraft?

 

[Reaper2008]

Why not flatten it in Ps?

 

[Storyyeller]

If you mean changing the alpha channel to a single bit, I already tried that. It didn't help.

If you mean combining the two images into one, well that kind of defeats the entire purpose of splitting them in the first place.

 

[Kwaliti]

You can clearly see the blue borders around the pyramids. Grab the eraser as a small soft brush with a small opacity and remove the borders.

 

[Storyyeller]

The first time, I tried it without the borders and the same thing happened. I added the borders to see if it would help, but it didn't.