The parameter name shall be "windowCenter" for URI based mode, and "WindowCenter" for the WS mode.

Controls the window center of the images as defined in PS3.3. This parameter is OPTIONAL for the URI based mode and the WS mode "Rendered Requester" transaction. It shall not be present for other WS mode transactions. This parameter is REQUIRED if "windowWidth" or "WindowWidth" is present. This parameter shall not be present if there is a presentationUID parameter. It shall not be present if contentType is application/dicom.

The value shall be encoded as a decimal string (DS), as specified in PS3.5.