White Edge on Transparent Texture

Use photoshop to remove those white pixels to transparent.

You must change the background color in the original image to match your edge color (the black border around your shape). Right now your background color is white when it should be black.

Note that you only need to extend the edge color by one or two pixels, not actually the entire background. Just enough to account for the fuzziness. Generally it's just easier to do the whole background. And easier to explain.

Here, I made a mini photoshop tutorial.

Step 1:

You have your image with a transparent background in Photoshop.

(If you already have an Alpha channel, you can skip to Step 6.)

Step 2:

Select your image layer and right-click.

Choose Select Layer Transparency.

Step 3:

Switch to the Channels tab.

Step 4:

At the bottom of the Channels tab, click on Save Selection as Channel.

Step 5:

This is just verifying what your alpha channel should look like.

Step 6:

Switch back to the Layers tab.

Add a new layer and move it to the bottom.

Fill the new layer with your edge color (in this case, black).

Step 7:

Save as TGA format. Make sure Alpha channels is checked in the SaveAs dialog. Make sure to select 32bit from the popup after you click Save. You may enable Compress RLE.