You can tell DITA2Go to use a specific named graphic in place of the original graphic. For example:
[GraphFiles] ; GraphicID (with or without extension) = new name (with extension) ; new name overrides any [Graphics]GraphPath specified ch01f853.gif = tuner.gif
If your DITA document references graphics in non-Web formats (such as TIFF) and you plan to replace those graphics with matching Web-usable images in the same directory, you can specify a new extension for the replacement files. For example:
[Graphics] ; GraphSuffix = suffix to use for replacement graphics GraphSuffix = jpg
If some referenced graphics are in a different format (for example GIF), specify the exceptions. For example:
[GraphSuffix] ; old suffix = new suffix, overrides [Graphics]GraphSuffix ; jpg = jpg leaves all .jpgs alone even if GraphSuffix=gif ; wmf = png .wmfs are being made into .pngs using a third-party tool gif = gif