wzip(1) [debian man page]
WZIP(1) General Commands Manual WZIP(1) NAME
wzip - lossy data compression and denoising SYNOPSIS
wzip [ -c | -d | -dn | -hdn ] num sf DESCRIPTION
This manual page documents the wzip command. wzip is a program that can be used for LOSSY data compression and denoising. It reads from STDIN and writes to STDOUT. In compression mode the input is a sequence of ascii floating-point values. num is the number of these data values. The output is a sequence of small inte- gers, most of them zero in typical application. This is ready for effective compression with a standard loss-less compression program like gzip. The program can also be used for denoising. In this case both input and output are sequences of ascii floating-point values. The scale factor sf determines the strength of compression or denoising. A higher scale factor means heavier compression and stronger denoising. Four times the standard deviation of the noise content is a good start. Otherwise 5 percent of the overall signal amplitude might be used as a first estimation of a suitable scale factor. If the noise content of the input data is strongly non-Gaussian-distributed, like Poisson noise. The input data should be transformed to approximate Gaussian-distributed noise. If the input values are Poisson-distributed, that means for example raw counts per channel in EDX or XPD, they can be transformed to approximate Gaussian-distributed noise by transformation of each data point with y:=2.0*sqrt(x+0.25109). Back transformation is done with y:=(x/2)^2. The summand 0.25109 compensates for the bias caused by the asymmetry of the Poisson-distribu- tion. Invoking the program without any options writes examples of the use of the program to STDERR. OPTIONS
There must be given exactly one option. -c Compression, reads num ascii floating-point values from STDIN and writes a sequence of integers with high redundancy to STDOUT. -d Decompression, reads from STDIN and writes a sequence of num ascii floating-point values to STDOUT. These are more or less similar to the original data. -dn Denoising, reads num ascii floating-point values from STDIN and writes a sequence of num ascii floating-point values to STDOUT. These are more or less similar to the original data. -hdn Denoising with hard thresholding instead of wavelet shrinkage. Single untouched noise peaks may be visible with this mode. On the other hand, there is much less impact on the signal slope. SEE ALSO
Donoho, D.L.; Johnstone, I.M.: Adapting to unknown smoothness via wavelet shrinkage, technical report 425, Department of Statistics, Stan- ford University, Stanford, June 1993, ftp://playfair.stanford.edu/pub/donoho/ausws.ps.Z Franzen, A.: Compression of process data with a wavelet method, steel res. 69 (1998), No. 1, pp. 28/30 Franzen, A.: Non-linear denoising with wavelet transformation, Z. Metallkd. 89 (1998), No. 4, pp. 297/302 AUTHOR
This manual page was written by Andreas Franzen <anfra@debian.org>, for the Debian GNU/Linux system (but may be used by others). Copyright (C) 1997 Andreas Franzen, placed under the GNU General Public License, see the file copyright for details. 24 December 1997 WZIP(1)
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TIFFCP(1) General Commands Manual TIFFCP(1) NAME
tiffcp - copy (and possibly convert) a TIFF file SYNOPSIS
tiffcp [ options ] src1.tif ... srcN.tif dst.tif DESCRIPTION
tiffcp combines one or more files created according to the Tag Image File Format, Revision 6.0 into a single TIFF file. Because the output file may be compressed using a different algorithm than the input files, tiffcp is most often used to convert between different compression schemes. By default, tiffcp will copy all the understood tags in a TIFF directory of an input file to the associated directory in the output file. tiffcp can be used to reorganize the storage characteristics of data in a file, but it is explicitly intended to not alter or convert the image data content in any way. OPTIONS
-b image subtract the following monochrome image from all others processed. This can be used to remove a noise bias from a set of images. This bias image is typically an image of noise the camera saw with its shutter closed. -B Force output to be written with Big-Endian byte order. This option only has an effect when the output file is created or overwrit- ten and not when it is appended to. -C Suppress the use of ``strip chopping'' when reading images that have a single strip/tile of uncompressed data. -c Specify the compression to use for data written to the output file: none for no compression, packbits for PackBits compression, lzw for Lempel-Ziv & Welch compression, zip for Deflate compression, lzma for LZMA2 compression, jpeg for baseline JPEG compression, g3 for CCITT Group 3 (T.4) compression, and g4 for CCITT Group 4 (T.6) compression. By default tiffcp will compress data according to the value of the Compression tag found in the source file. The CCITT Group 3 and Group 4 compression algorithms can only be used with bilevel data. Group 3 compression can be specified together with several T.4-specific options: 1d for 1-dimensional encoding, 2d for 2-dimensional encoding, and fill to force each encoded scanline to be zero-filled so that the terminating EOL code lies on a byte boundary. Group 3-specific options are specified by appending a ``:''-separated list to the ``g3'' option; e.g. -c g3:2d:fill to get 2D-encoded data with byte-aligned EOL codes. LZW, Deflate and LZMA2 compression can be specified together with a predictor value. A predictor value of 2 causes each scanline of the output image to undergo horizontal differencing before it is encoded; a value of 1 forces each scanline to be encoded without differencing. A value 3 is for floating point predictor which you can use if the encoded data are in floating point format. LZW- specific options are specified by appending a ``:''-separated list to the ``lzw'' option; e.g. -c lzw:2 for LZW compression with horizontal differencing. Deflate and LZMA2 encoders support various compression levels (or encoder presets) set as character ``p'' and a preset number. ``p1'' is the fastest one with the worst compression ratio and ``p9'' is the slowest but with the best possible ratio; e.g. -c zip:3:p9 for Deflate encoding with maximum compression level and floating point predictor. -f Specify the bit fill order to use in writing output data. By default, tiffcp will create a new file with the same fill order as the original. Specifying -f lsb2msb will force data to be written with the FillOrder tag set to LSB2MSB, while -f msb2lsb will force data to be written with the FillOrder tag set to MSB2LSB. -i Ignore non-fatal read errors and continue processing of the input file. -l Specify the length of a tile (in pixels). tiffcp attempts to set the tile dimensions so that no more than 8 kilobytes of data appear in a tile. -L Force output to be written with Little-Endian byte order. This option only has an effect when the output file is created or over- written and not when it is appended to. -M Suppress the use of memory-mapped files when reading images. -p Specify the planar configuration to use in writing image data that has one 8-bit sample per pixel. By default, tiffcp will create a new file with the same planar configuration as the original. Specifying -p contig will force data to be written with multi-sample data packed together, while -p separate will force samples to be written in separate planes. -r Specify the number of rows (scanlines) in each strip of data written to the output file. By default (or when value 0 is specified), tiffcp attempts to set the rows/strip that no more than 8 kilobytes of data appear in a strip. If you specify special value -1 it will results in infinite number of the rows per strip. The entire image will be the one strip in that case. -s Force the output file to be written with data organized in strips (rather than tiles). -t Force the output file to be written with data organized in tiles (rather than strips). options can be used to force the resultant image to be written as strips or tiles of data, respectively. -w Specify the width of a tile (in pixels). tiffcp attempts to set the tile dimensions so that no more than 8 kilobytes of data appear in a tile. tiffcp attempts to set the tile dimensions so that no more than 8 kilobytes of data appear in a tile. -x Force the output file to be written with PAGENUMBER value in sequence. -,=character substitute character for `,' in parsing image directory indices in files. This is necessary if filenames contain commas. Note that -,= with whitespace immediately following will disable the special meaning of the `,' entirely. See examples. EXAMPLES
The following concatenates two files and writes the result using LZW encoding: tiffcp -c lzw a.tif b.tif result.tif To convert a G3 1d-encoded TIFF to a single strip of G4-encoded data the following might be used: tiffcp -c g4 -r 10000 g3.tif g4.tif (1000 is just a number that is larger than the number of rows in the source file.) To extract a selected set of images from a multi-image TIFF file, the file name may be immediately followed by a `,' separated list of image directory indices. The first image is always in directory 0. Thus, to copy the 1st and 3rd images of image file ``album.tif'' to ``result.tif'': tiffcp album.tif,0,2 result.tif A trailing comma denotes remaining images in sequence. The following command will copy all image with except the first one: tiffcp album.tif,1, result.tif Given file ``CCD.tif'' whose first image is a noise bias followed by images which include that bias, subtract the noise from all those images following it (while decompressing) with the command: tiffcp -c none -b CCD.tif CCD.tif,1, result.tif If the file above were named ``CCD,X.tif'', the -,= option would be required to correctly parse this filename with image numbers, as fol- lows: tiffcp -c none -,=% -b CCD,X.tif CCD,X%1%.tif result.tif SEE ALSO
pal2rgb(1), tiffinfo(1), tiffcmp(1), tiffmedian(1), tiffsplit(1), libtiff(3TIFF) Libtiff library home page: http://www.remotesensing.org/libtiff/ libtiff February 24, 2007 TIFFCP(1)