alosca
June 16, 2025, 6:40pm
41
Thanks for checking. Would it be shown as Deflate? See below, together with other evidences for support of ZIP. Not that I want to add extra work for you, really, just sharing what I found.
LibTIFF, a library for reading and writing TIFF files, supports various compression schemes, including Deflate , also known as ZIP compression .
From tiffcp source code I get
else if (strneq(opt, "zip", 3))
{
processZIPOptions(opt);
defcompression = COMPRESSION_ADOBE_DEFLATE;
}
showing COMPRESSION_ADOBE_DEFLATE as the compression type. Also,
#ifdef ZIP_SUPPORT
" -c zip[:opts] compress output with deflate encoding\n"
/* " Deflate (ZIP) options:", */
" # set predictor value\n"
" p# set compression level (preset)\n"
" For example, -c zip:3:p9 for maximum compression level and floating\n"
" point predictor.\n"
#endif
#if defined(ZIP_SUPPORT) && defined(LIBDEFLATE_SUPPORT)
" s# set subcodec: 0=zlib, 1=libdeflate (default 1)\n"
/* " (only for Deflate/ZIP)", */
#endif
ZIP_SUPPORT is defined in my system (Ubuntu) in tiffconf.h,
/usr/include/x86_64-linux-gnu/tiffconf.h:#define ZIP_SUPPORT 1
/* Support Deflate compression */
#define ZIP_SUPPORT 1
libdeflate-dev gets installed when libtiff-dev is installed,
/* Support libdeflate enhanced compression */
#define LIBDEFLATE_SUPPORT 1
Here an excerpt from file tiff.h :
#define TIFFTAG_COMPRESSION 259 /* data compression technique */
#define COMPRESSION_NONE 1 /* dump mode */
#define COMPRESSION_CCITTRLE 2 /* CCITT modified Huffman RLE */
#define COMPRESSION_CCITTFAX3 3 /* CCITT Group 3 fax encoding */
#define COMPRESSION_CCITT_T4 3 /* CCITT T.4 (TIFF 6 name) */
#define COMPRESSION_CCITTFAX4 4 /* CCITT Group 4 fax encoding */
#define COMPRESSION_CCITT_T6 4 /* CCITT T.6 (TIFF 6 name) */
#define COMPRESSION_LZW 5 /* Lempel-Ziv & Welch */
#define COMPRESSION_OJPEG 6 /* !6.0 JPEG */
#define COMPRESSION_JPEG 7 /* %JPEG DCT compression */
#define COMPRESSION_T85 9 /* !TIFF/FX T.85 JBIG compression */
#define COMPRESSION_T43 10 /* !TIFF/FX T.43 colour by layered JBIG compression */
#define COMPRESSION_NEXT 32766 /* NeXT 2-bit RLE */
#define COMPRESSION_CCITTRLEW 32771 /* #1 w/ word alignment */
#define COMPRESSION_PACKBITS 32773 /* Macintosh RLE */
#define COMPRESSION_THUNDERSCAN 32809 /* ThunderScan RLE */
/* codes 32895-32898 are reserved for ANSI IT8 TIFF/IT <dkelly@apago.com) */
#define COMPRESSION_IT8CTPAD 32895 /* IT8 CT w/padding */
#define COMPRESSION_IT8LW 32896 /* IT8 Linework RLE */
#define COMPRESSION_IT8MP 32897 /* IT8 Monochrome picture */
#define COMPRESSION_IT8BL 32898 /* IT8 Binary line art */
/* compression codes 32908-32911 are reserved for Pixar */
#define COMPRESSION_PIXARFILM 32908 /* Pixar companded 10bit LZW */
#define COMPRESSION_PIXARLOG 32909 /* Pixar companded 11bit ZIP */
#define COMPRESSION_DEFLATE 32946 /* Deflate compression */
#define COMPRESSION_ADOBE_DEFLATE 8 /* Deflate compression,
as recognized by Adobe */
/* compression code 32947 is reserved for Oceana Matrix <dev@oceana.com> */
#define COMPRESSION_DCS 32947 /* Kodak DCS encoding */
#define COMPRESSION_JBIG 34661 /* ISO JBIG */
#define COMPRESSION_SGILOG 34676 /* SGI Log Luminance RLE */
#define COMPRESSION_SGILOG24 34677 /* SGI Log 24-bit packed */
#define COMPRESSION_JP2000 34712 /* Leadtools JPEG2000 */
#define COMPRESSION_LERC 34887 /* ESRI Lerc codec: https://github.com/Esri/lerc */
/* compression codes 34887-34889 are reserved for ESRI */
#define COMPRESSION_LZMA 34925 /* LZMA2 */
#define COMPRESSION_ZSTD 50000 /* ZSTD: WARNING not registered in Adobe-maintained registry */
#define COMPRESSION_WEBP 50001 /* WEBP: WARNING not registered in Adobe-maintained registry */
#define COMPRESSION_JXL 50002 /* JPEGXL: WARNING not registered in Adobe-maintained registry */
What I propose then is to allow all these kind of compression techniques in GāMIC, by specifying the compression COMPRESSION_XXX as the string xxx or XXX.
committed 07:36PM - 16 Jun 25 UTC
and
committed 07:36PM - 16 Jun 25 UTC
Iāll post new prerelease sources and package probably tomorrow.
alosca
June 16, 2025, 10:01pm
44
That will be excellent, thanks!
I donāt know why COMPRESSION_ZIP is not included since it is so commonly used by that name, ZIP, also referenced by tiffcp, which comes with libtiff package (they donāt list DEFLATE as a compression option),
-c zip[:opts] compress output with deflate encoding
In fact, I have this in my tiff.h, note the legacy tag observation,
#define COMPRESSION_DEFLATE 32946 /* Deflate compression, legacy tag */
When I use tiffcp -c zip to compress the compression tag in the file is then AdobeDeflate not Deflate, as shown below after calling tiffinfo foot.tif
=== TIFF directory 1267 ===
All this to say that it would probably be advantageous to have āzipā as an option when saving a tiff with gmic, if at all possible, e.g.
gmic .... -o foot.tif,uint16,zip
alosca:
All this to say that it would probably be advantageous to have āzipā as an option when saving a tiff with gmic, if at all possible, e.g.
gmic .... -o foot.tif,uint16,zip
Yes I can do that, I will associate the term āzipā to āadobe_deflateā.