SetQuality Method

In This Topic

Description

Set the compression quality for a given transfer context

Syntax

Visual Basic
Public Sub SetQuality( _ ByVal TransferSyntax As String, _ ByVal Quality As Variant _ )

Parameters

TransferSyntax: The transfer syntax to which this quality factor applies
Quality: The quality to be set

Remarks

An application does not necessarily “know” which images will be sent by which transfer syntax, as the remote AE may have accepted different transfer syntaxes for different abstract syntaxes, and a common quality factor for an association would not therefore be appropriate. Instead, this method allows quality to be set for a specific transfer syntax.
The quality is specific to a given association rather than to the connection itself, and this method must therefore be after the call to SetDestination.

The following limitations apply:

This method is only meaningful when used in an application actually sending an image (normally the SCP), as there is no official means in DICOM for the SCU to send this information to the SCP.
Where an image is already compressed using the transfer syntax required, it is not decompressed and recompressed, so this value is ignored. If absolutely necessary, this can be over-ridden by applying the DecompressAll method to the image before sending it, but multiple compressions do have an adverse effect on image quality

At present, the only syntaxes to which this method applies are doTS_JPEGBaseline (1.2.840.10008.1.2.4.50) and doTS_JPEGExtended (1.2.840.10008.1.2.4.51), though it is also made available to private syntaxes defined through compression DLLs.

The Quality is defined as a variant in order to allow future transfer syntaxes to define their own types of quality factor.