The parameter name shall be “columns” for URI based mode, and “Columns” for the WS mode .
The value shall be expressed as an integer, representing the image width to be returned. It is OPTIONAL for the URI based mode and the WS mode “Rendered Requester” transaction. It shall not be present if contentType is application/dicom.
If both “rows” and “columns” are specified, then each shall be interpreted as a maximum, and a size will be chosen for the image s within these constraints, maintaining the correct aspect ratio. If the number of columns is absent and the number of rows is present, the number of columns shall be chosen in order to maintain the correct aspect ratio. If both are absent, the image s (or selected region) is are sent in its their original size (or the size of the presentation state applied on the image s ), resulting as one pixel of screen for one pixel of the image s .
The value shall be encoded as an integer string (IS), as specified in PS 3.5.