If replacement graphics have the same base names as the originals, and are located in the same directory with the originals, and you are replacing some or all GIFs with BMPs:
[Graphics]
FilePaths=Retain
FileNames=Map
If all replacement graphics are in the project directory, and you are replacing GIFs with BMPs, and in one instance replacing an existing BMP with a new one:
[Graphics]
FilePaths=None
FileNames=Map
[GraphFiles]
gif=bmp
oldpic.bmp=newpic.bmp
If some replacement graphics are not with originals and not in the project directory, you must specify paths to the replacement files:
[Graphics]
FilePaths=None
FileNames=Map
[GraphFiles]
oldpic.bmp=D:/Graphics/Beta/newpic.bmp
If some of the replacement graphics are in the same directory as the original graphics, but some of the base file names are different, you must specify both the original and the replacement path:
[Graphics]
FilePaths=Retain
FileNames=Map
[GraphFiles]
D:/Graphics/oldpic.bmp=D:/Graphics/newpic.bmp
Because path references in DITA could be relative or absolute, it is better to avoid specifying paths to the left of the equals sign in [GraphFiles]; instead, move or copy the replacement graphics to the project directory, and set FilePaths=None.