Provides methods for encoding and decoding PDF streams. The main classes are {@link com.etymon.pjx.stream.PdfEncodeStream PdfEncodeStream} and {@link com.etymon.pjx.stream.PdfDecodeStream PdfDecodeStream}, which provide the most commonly used functions. If more control is needed, the classes that implement {@link com.etymon.pjx.stream.PdfStreamFilter PdfStreamFilter} can be used directly.