Images that are used within UIElements are exposed as separate Variables rather than embedding them in the element. All image Variables will be aggregated by the ImageSet folder. The UIElement shall specify an image by its name that is also the BrowseName of the image Variable. Clients can cache images so they don't have to be transferred more than once. The “ImageSet” Folder is formally defined in Table 24.

Table 24 – ImageSet definition

Attribute	Value
BrowseName	ImageSet
References	NodeClass	BrowseName	TypeDefinition	DataType	ModellingRule
HasTypeDefinition	ObjectType	FolderType (defined in OPC 10000-5.)
HasComponent	Variable	<ImageIdentifier>	BaseDataVariableType	Image	MandatoryPlaceholder

The DataType of the Variable specifies the image format. OPC UA defines BMP, GIF, JPG and PNG (see OPC 10000-3).