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SECTION 3.3 Filters
TABLE 3.5 Standard filters
FILTER NAME PARAMETERS? DESCRIPTION
ASCIIHexDecode no Decodes data encoded in an ASCII hexadecimal representation,
reproducing the original binary data.
ASCII85Decode no Decodes data encoded in an ASCII base-85 representation, repro-
ducing the original binary data.
LZWDecode yes Decompresses data encoded using the LZW (Lempel-Ziv-Welch)
adaptive compression method, reproducing the original text or bin-
ary data.
FlateDecode yes (PDF 1.2) Decompresses data encoded using the zlib/deflate com-
pression method, reproducing the original text or binary data.
RunLengthDecode no Decompresses data encoded using a byte-oriented run-length encod-
ing algorithm, reproducing the original text or binary data (typically
monochrome image data, or any data that contains frequent long
runs of a single byte value).
CCITTFaxDecode yes Decompresses data encoded using the CCITT facsimile standard,
reproducing the original data (typically monochrome image data at 1
bit per pixel).
JBIG2Decode yes (PDF 1.4) Decompresses data encoded using the JBIG2 standard,
reproducing the original monochrome (1 bit per pixel) image data
(or an approximation of that data).
DCTDecode yes Decompresses data encoded using a DCT (discrete cosine transform)
technique based on the JPEG standard, reproducing image sample
data that approximates the original data.
JPXDecode no (PDF 1.5) Decompresses data encoded using the wavelet-based
JPEG2000 standard, reproducing the original image data.
Crypt yes (PDF 1.5) Decrypts data encrypted by a security handler, reproduc-
ing the original data as it was before encryption.
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