Custom headers for the WordPress plugin directory

Very simple, All you need to create a image of size exactly 772×250 pixel and name it as banner-772x250.jpg. You have to save this image in /assets/ folder in your plugins SVN directory.

• Make sure the image is of either .png or .jpg type.
• The .gif images are not allowed.
• It may take upto 15 minitues to appear on your plugin page.
• Another note - WordPress adds title to lower left corner of image.

Here is the example directory location and image name assets/banner-772x250.jpg) OR assets/banner-772x250.png

Link to official update by matt (cofounder of wordpress )

Also, from the Codex:

For development and testing, you can add a URL parameter to your plugin's URL of "?banner_url=A_LINK_TO_YOUR_IMAGE" to preview what the page will look like with your own image. This will only work with your own plugins, you can not use this parameter on anybody else's plugins.