CompressionType

Express the desired compression type when encoding an image. Be aware that most image types only support a sub-set of the available compression types. If the compression type specified is incompatible with the image, ImageMagick selects a compression type compatible with the image type.

Values

ValueMeaning
UndefinedCompression
NoCompression

The default for most formats.

BZipCompression

BZip (Burrows-Wheeler block-sorting text compression algorithm and Huffman coding) as used by bzip2 utilities

DXT1Compression
DXT3Compression
DXT5Compression
FaxCompression

CCITT Group 3 FAX compression.

Group4Compression

CCITT Group 4 FAX compression (used only for TIFF).

JPEGCompression

JPEG compression.

See_Also: The JPEG image compression FAQ.

JPEG2000Compression

JPEG2000 compression for compressed PDF images.

ISO/IEC std 15444-1

LosslessJPEGCompression
LZWCompression

Lempel-Ziv-Welch (LZW) compression.

RLECompression

Run-length encoding.

See_Also: Wikipedia.

ZipCompression

Lempel-Ziv compression (LZ77) as used in PKZIP and GNU gzip.

ZipSCompression
PizCompression
Pxr24Compression
B44Compression
B44ACompression
LZMACompression

Lempel-Ziv-Markov chain algorithm

JBIG1Compression

ISO/IEC std 11544 / ITU-T rec T.82

JBIG2Compression

ISO/IEC std 14492 / ITU-T rec T.88

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