Value | Meaning |
---|---|
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 |
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.