From c0b89ac5bfb90835ef01573267020e42d4fe070c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= Date: Sun, 23 Aug 2015 12:17:05 +0200 Subject: Imported Upstream version 1.8.0 --- tiff/contrib/addtiffo/README | 142 ------------------------------------------- 1 file changed, 142 deletions(-) delete mode 100644 tiff/contrib/addtiffo/README (limited to 'tiff/contrib/addtiffo/README') diff --git a/tiff/contrib/addtiffo/README b/tiff/contrib/addtiffo/README deleted file mode 100644 index a6ca45f..0000000 --- a/tiff/contrib/addtiffo/README +++ /dev/null @@ -1,142 +0,0 @@ - addtiffo 1.0 - ============ - -The addtiffo utility is used to add overview pyramids to an existing -TIFF or GeoTIFF file. Some applications can take advantage of these -overviews to accelerate overview display performance of large rasters. - -This release of addtiffo is primarily intended for compatibility testing -with applications, and to see if there is interest in a cleaner release -of the capability ... perhaps incorporation into the libtiff tools -distribution. - -Please feel free to contact me with questions, or problems. - -warmerda@home.com -http://home.gdal.org/~warmerda/ - - -Usage ------ - -Usage: addtiffo [-r {average/nearest} [-subifd] - tiff_filename [resolution_reductions] - -Example: - % addtiffo abc.tif 2 4 8 16 - -The numeric arguments are the list of reduction factors to -generate. In this example a 1/2, 1/4 1/8 and 1/16 - - - -Limitations ------------ - -See tif_overview.cpp for up to date details. - - o Currently only images with bits_per_sample of a multiple of eight - will work. - - o The code will attempt to use the same kind of compression, - photometric interpretation, and organization as the source image, but - it doesn't copy geotiff tags to the reduced resolution images. - - o Reduced resolution overviews for multi-sample files will currently - always be generated as PLANARCONFIG_SEPARATE. This could be fixed - reasonable easily if needed to improve compatibility with other - packages. Many don't properly support PLANARCONFIG_SEPARATE. - - o Overviews are always written as appended IFDs, rather than using the - ``tree of tree's'' approach using the SUBIFD tag. I wanted to implement - both, but it isn't currently easy to add a SUBIFD tag to an existing - main tiff IFD with libtiff. I hope to try this again later. - - -TIFF File Tags --------------- - -The results of running addtiffo on a 1024x1024 tiled greyscale file -with the arguments ``2 4 8 16'' is to add four additional TIFF directories -appended on the file with the SUBFILETYPE flag to 0x1 indicating the extra -items are reduced resolution images. - -The tiffinfo output of such a file might look like this: - -TIFF Directory at offset 0x118008 - Image Width: 1024 Image Length: 1024 - Tile Width: 256 Tile Length: 112 - Bits/Sample: 8 - Compression Scheme: none - Photometric Interpretation: min-is-black - Samples/Pixel: 1 - Planar Configuration: single image plane -TIFF Directory at offset 0x15e1d2 - Subfile Type: reduced-resolution image (1 = 0x1) - Image Width: 512 Image Length: 512 - Tile Width: 256 Tile Length: 112 - Bits/Sample: 8 - Compression Scheme: none - Photometric Interpretation: min-is-black - Samples/Pixel: 1 - Planar Configuration: separate image planes -TIFF Directory at offset 0x1732b8 - Subfile Type: reduced-resolution image (1 = 0x1) - Image Width: 256 Image Length: 256 - Tile Width: 256 Tile Length: 112 - Bits/Sample: 8 - Compression Scheme: none - Photometric Interpretation: min-is-black - Samples/Pixel: 1 - Planar Configuration: separate image planes -TIFF Directory at offset 0x17a366 - Subfile Type: reduced-resolution image (1 = 0x1) - Image Width: 128 Image Length: 128 - Tile Width: 128 Tile Length: 112 - Bits/Sample: 8 - Compression Scheme: none - Photometric Interpretation: min-is-black - Samples/Pixel: 1 - Planar Configuration: separate image planes -TIFF Directory at offset 0x17b40c - Subfile Type: reduced-resolution image (1 = 0x1) - Image Width: 64 Image Length: 64 - Tile Width: 64 Tile Length: 64 - Bits/Sample: 8 - Compression Scheme: none - Photometric Interpretation: min-is-black - Samples/Pixel: 1 - Planar Configuration: separate image planes - - -Building --------- - -You will need a C compiler. You will need to have libtiff already -built and installed. The provided Makefile should work on most Unix systems. -A similar file will be needed for Windows, but is not provided. - -The CFLAGS and LIBS macros in the Makefile will have to be updated to -point to the correct location of the libtiff include files, and library. - - -Credits -------- - - o Intergraph Corporation for partially funding the work. - - o Global Geomatics for partially funding reorganization of the overview - building ability as a separate utility. - - o Orrin Long, and Ed Grissom of Intergraph for explaining what needed to - be done. - - o Max Martinez of Erdas for his discussion of external overviews. - - o Atlantis Scientific who supported adding averaging, and some other - generalizations. - - o Frank Warmerdam for writing the bulk of the code. - - o Sam Leffler since this only exists because of his libtiff. - -- cgit v1.2.3