superimpose on picture

[Blighty]

1. Make sure the image has an alpha channel. Right click the layer in the layers dialogue and Add Alpha Channel. If it is greyed out there already is an alpha channel.

2. Use the Fuzzy Select tool to select the white background. Set threshold as needed.

3. Edit > Clear or press the delete key.

There will probably be a white halo around the figure. Get rid of this as follows:

4. Select > Grow by 1 or 2 pixels

5. Colours > Colour to Alpha accept the default white

6. Select > None

Copy this image and paste into another as a new layer.