How do I create the ".gif" file to be added in the title of the Toolbox roadmap in the MATLAB Help?

I defined a MATLAB toolbox and I need to include the help documentation. I created a product page roadmap and I need to include the title in the header that is usually provided as a "gif" image (the template is called begin_here.gif). In order to match the style of the other toolboxes in the MATLAB help, I would like to modify that picture with the title of my Toolbox. How is the usual procedure to do that? As far as I know, the text in the begin_here.gif cannot be edited. Could be that the begin_here.gif is automatically generated (MATLAB macro) with the title of the desired Toolbox?