Some image mime types may require to be a file-based import and some require a stream-based import, other types can be either. By default the system uses a stream-based import but the InDesignConfig.xml file contains configuration to determine which image mime types should be processed using a file-based import routine.
<InDesignConfig
LinkPing="10000"
ArchivePDFVariantName="PDF_[Press quality]"
PrintPDFName="[Press quality]"
PageCompleteWorkstate="Page Closed"
PrintQueueName="PDF file"
PrintSinglePages="false"
port="5679"
ColourForMissingAdverts="16711935"
SendToNewsroomFolderPath="/Wires"
AutoMarkNonEmptyTextBoxes="true"
KeepAlivePing="120000"
ThumbnailHeight="96.0">
<ImageFileMimeTypes>
<ImageFileMimeType>image/pdf
</ImageFileMimeType>
</ImageFileMimeTypes>
</InDesignConfig>
The file extension types listed between the <ImageFileMimeType> </ImageFileMimeType> tags determine which image types are processed by the file-based routines. PDF files need to be configured for this option.