Which streams a save compresses with the FlateDecode encoder.
public enum PdfStreamCompression
ISO 32000-2 §7.4.1 and §7.4.4. Only streams without a Filter entry (and without DecodeParms or an external file,
§7.3.8.2 Table 5) are compressed; a stream that already has filters is written as it is. Metadata streams (§14.3.2) are never
compressed, so that tools which scan a file for its XMP packet still find it (PDF/A-1, ISO 19005-1, forbids filtering them).
A stream is written compressed only when that makes it smaller, its Filter entry included.
The document itself is not changed: the compressed copy exists only in the written file. The streams a save creates (object streams, the cross-reference stream) are always compressed, whatever this setting.
kind:method, kind:property, kind:ctor. Press Esc to clear.AllStreamsCompresses every unfiltered stream, changed or not; unchanged unfiltered streams are written anew instead of copied.ChangedStreamsCompresses unfiltered streams that are new or have changed since the document was read. Unchanged objects keep the exact bytes they were read from. The default.NoneWrites every stream's data as it is.