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CentOS 7.0 - man page for pamtotiff (centos section 0)

Pamtotiff User Manual(0)						 Pamtotiff User Manual(0)

NAME
       pamtotiff - convert a Netpbm image to a TIFF file

SYNOPSIS
       pamtotiff

       [-none | -packbits | -lzw | -g3 | -g4 | -flate | -adobeflate]

       [-2d]

       [-fill]

       [-predictor=n]

       [-msb2lsb|-lsb2msb]

       [-rowsperstrip=n]

       [-minisblack|-miniswhite|mb|mw]

       [-truecolor]

       [-color]

       [-indexbits=bitwidthlist] [-xresolution=xres]

       [-yresolution=yres] [-resolutionunit={inch | centimeter | none | in | cm | no}]

       [-indexbits=[1[2[4[8]]]]]

       [-append]

       [-tag=taglist]

       [pamfile]

       You  can  use  the  minimum  unique  abbreviation of the options.  You can use two hyphens
       instead of one.	You can separate an option name from its value with white  space  instead
       of an equals sign.

DESCRIPTION
       This program is part of Netpbm(1)

       pamtotiff reads a PNM or PAM image as input and produces a TIFF file as output.

       Actually,  it handles multi-image Netpbm streams, producing multi-image TIFF streams (i.e.
       a TIFF stream with multiple 'directories').  But before	Netpbm	10.27  (March  2005),  it
       ignored all but the first Netpbm image in the input stream.

   The Output File
       The  output  goes  to  Standard Output.	pamtotiff approaches this output file differently
       from Unix and Netpbm convention.  This is entirely due to  pamtotiff's  use  of	the  TIFF
       library to do all TIFF output.

       o      The  output  file  must  be  seekable.   pamtotiff  does not write it sequentially.
	      Therefore, you can't use a pipe; you can't pipe the output  of  pamtotiff  to  some
	      other program.  But any regular file should work.

       o      If the output file descriptor is readable, you must either specify -append so as to
	      add to the existing file, or make sure the file  is  empty.   Otherwise,	pamtotiff
	      will fail with an unhelpful message telling you that a TIFF library function failed
	      to open the TIFF output stream.

       o      If you are converting multiple images (your input stream contains multiple images),
	      the output file must be both readable and writable.

       If you're using a Unix command shell to run pamtotiff, you use facilities of your shell to
       set up Standard Output.	In Bash, for example, you would set up a write-only Standard Out-
       put to the file /tmp/myimage.tiff like this:

	   $ pamtotiff myimage.pnm >/tmp/myimage.tiff

       In  Bash, you would set up a read/write Standard Output to the file /tmp/myimage.tiff like
       this:

	   $ pamtotiff myimage.pnm 1<>/tmp/myimage.tiff

   TIFF Capability
       pamtotiff uses the Libtiff.org TIFF library (or whatever equivalent you provide) to gener-
       ate  the  TIFF output.  Details of the format it produces are therefore controlled by that
       library.

OPTIONS
   Compression
       By default, pamtotiff creates a TIFF file with no compression.  This is your best bet most
       of  the	time.	If  you want to try another compression scheme or tweak some of the other
       even more obscure output options, there are a number of options which to play.

       Before Netpbm 8.4 (April 2000), the default was to use  LZW  compression.   But	then  new
       releases  of  the TIFF library started omitting the LZW compression capability due to con-
       cern about patents on LZW.  So since then, the default has been no compression.	 The  LZW
       patents have now expired and new TIFF libraries do LZW, but the pamtotiff behavior remains
       the same for compatibility with older TIFF libraries and applications of pamtotiff.

       The -none, -packbits, -lzw, -g3, -g4, -flate, and -adobeflate options are used to override
       the default and set the compression scheme used in creating the output file.

       The  -predictor	option	is  meaningful	only with LZW compression: 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.  By
       default, pamtotiff creates a TIFF file with  msb-to-lsb	fill  order.   The  -msb2lsb  and
       -lsb2msb  options are used to override the default and set the fill order used in creating
       the file.

       With some older TIFF libraries, -lzw doesn't work because the TIFF library doesn't do  LZW
       compression.   This  is because of concerns about Unisys's patent on LZW which was then in
       force.  Actually, with very old TIFF libraries, -lzw works because no distributors of  the
       TIFF library were sensitive yet to the patent issue.

       -flate  chooses	'flate'  compression,  which is the patent-free compression common in the
       Unix world implemented by the 'Z' library.  It is what the PNG format uses.

       Fax Compression

       If you have bilevel data (e.g. PBM), you can generate a TIFF that uses the  same  compres-
       sion scheme specified for use by fax machines.  See the FaxFormat(1)
	page for more information on these compression schemes.

       These formats all relate to ITU Group 3 and Group 4 fax machine standards.

       The -g3 option chooses MH or MR compression: MR with the additional option -2d; MH without
       it.  -g4 selects MMR.  The option names are a little unfortunate and historical,  but  are
       consistent with the TIFF specification.

       MMR has a better compression ratio than the other two.

       -fill  specifies that for MH or MR compression, each encoded scanline shall be zero-filled
       to a byte boundary.

       -2d and -fill are meaningful only with -g3.

   Fill Order
       The -msb2lsb and lsb2msb options control the fill order.

       The fill order is the order in which pixels are packed into a byte in the Tiff raster,  in
       the case that there are multiple pixels per byte.  msb-to-lsb means that the leftmost col-
       umns go into the most significant bits of the byte in the Tiff image.  However,	there  is
       considerable  confusion about the meaning of fill order.  Some believe it means whether 16
       bit sample values in the Tiff image are little-endian  or  big-endian.	This  is  totally
       erroneous  (The	endianness of integers in a Tiff image is designated by the image's magic
       number).  However, ImageMagick and older Netpbm both have been  known  to  implement  that
       interpretation.	2001.09.06.

       If the image does not have sub-byte pixels, these options have no effect other than to set
       the value of the FILLORDER tag in the Tiff image (which may be useful for  those  programs
       that misinterpret the tag with reference to 16 bit samples).

   Color Space
       -color  tells  pamtotiff  to  produce  a color, as opposed to grayscale, TIFF image if the
       input is PPM, even if it contains only shades of gray.	Without  this  option,	pamtotiff
       produces  a grayscale TIFF image if the input is PPM and contains only shades of gray, and
       at most 256 shades.  Otherwise, it produces a color TIFF output.  For PBM and  PGM  input,
       pamtotiff always produces grayscale TIFF output and this option has no effect.

       The  -color  option  can  prevent pamtotiff from making two passes through the input file,
       thus improving speed and memory usage.  See Multiple Passes <#multipass> .

       -truecolor tells pamtotiff to produce the 24-bit RGB form of TIFF output if it is  produc-
       ing  a color TIFF image.  Without this option, pamtotiff produces a colormapped (paletted)
       TIFF image unless there are more than 256 colors (and in the latter case, issues  a  warn-
       ing).

       The -truecolor option can prevent pamtotiff from making two passes through the input file,
       thus improving speed and memory usage.  See Multiple Passes <#multipass> .

       The -color and -truecolor options did not exist before Netpbm 9.21 (December 2001).

       If pamtotiff produces a grayscale TIFF image, this option has no effect.

       The -minisblack and -miniswhite options force the output  image	to  have  a  'minimum  is
       black' or 'minimum is white' photometric, respectively.	If you don't specify either, pam-
       totiff uses minimum is black except when using Group 3 or Group 4  compression,	in  which
       case  pamtotiff	follows  CCITT	fax  standards	and uses 'minimum is white.' This usually
       results in better compression and is generally preferred for bilevel coding.

       Before February 2001, pamtotiff always produced 'minimum is black,'  due  to  a	bug.   In
       either  case, pamtotiff sets the photometric interpretation tag in the TIFF output accord-
       ing to which photometric is actually used.

       The -indexbits option is meaningful only for a colormapped (paletted) image.  In this kind
       of  image,  the	raster contains values which are indexes into a table of colors, with the
       indexes normally taking less space that the color description in the table.  pamtotiff can
       generate  indexes of 1, 2, 4, or 8 bits.  By default, it will use 8, because many programs
       that interpret TIFF images can't handle any other width.

       But if you have a small number of colors, you can make your image considerably smaller  by
       allowing  fewer than 8 bits per index, using the -indexbits option.  The value is a comma-
       separated list of the bit widths you allow.  pamtotiff  chooses	the  smallest  width  you
       allow  that allows it to index the entire color table.  If you don't allow any such width,
       pamtotiff fails.  Normally, the only useful value for this option is  1,2,4,8,  because	a
       program either understands the 8 bit width (default) or understands them all.

       In  a  Baseline	TIFF image, according to the 1992 TIFF 6.0 specification, 4 and 8 are the
       only valid widths.  There are no formal standards that allow any other values.

       This option was added in June 2002.  Before that, only 8 bit indices were possible.

   Extra Tags
       There are lots of tag types in the TIFF format that don't correspond to any information in
       the  PNM  format or to anything in the conversion process.  For example, a TIFF_ARTIST tag
       names the artist who created the image.

       You can tell pamtotiff explicitly to include tags such as this in its output with the -tag
       option.	 You  identify a list of tag types and values and pamtotiff includes a tag in the
       output for each item in your list.

       The value of -tag is the list of tags, like this example:

	   -tag=subfiletype=reducedimage,documentname=Fred,xposition=25

       As you see, it is a list of tag specifications separated by commas.  Each  tag  specifica-
       tion  is  a  name and a value separated by an equal sign.  The name is the name of the tag
       type, except in arbitrary upper/lower case.  One place to see the names of TIFF tag  types
       is  in  the TIFF library's tiff.h file, where there is a macro defined for each consisting
       of 'TIFF_' plus the name.  E.g. for the SUBFILETYPE tag type, there is a  macro	TIFF_SUB-
       FILETYPE.

       The  format of the value specification for a tag (stuff after the equal sign) depends upon
       what kind of value the tag type has:

       o      Integer: a decimal number

       o      Floating point number: a decimal number

       o      String: a string

       o      Enumerated (For example, a 'subfiletype' tag takes an enumerated value.  Its possi-
	      ble  values are REDUCEDIMAGE, PAGE, and MASK.): The name of the value.  You can see
	      the possible value names in the TIFF library's tiff.h file, where there is a  macro
	      defined  for  each  consisting  of  a  qualifier plus the value name.  E.g. for the
	      REDUCEDIMAGE value of a SUBFILETYPE tag, you see the macro FILETYPE_REDUCEDIMAGE.

	      The TIFF format assigns a unique number to each enumerated value and you can  spec-
	      ify that number, in decimal, as an alternative.  This is useful if you are using an
	      extension of TIFF that pamtotiff doesn't know about.

       If you specify a tag type with -tag that is not independent of the  content  of	your  PNM
       source  image  and  pamtotiff's	conversion process (i.e. a tag type in which pamtotiff is
       interested), pamtotiff fails.  For example, you cannot  specify	an  IMAGEWIDTH	tag  with
       -tag,  because  pamtotiff  generates  an IMAGEWIDTH tag that gives the actual width of the
       image.

       -tag was new in Netpbm 10.31 (December 2005).

   Other
       You can use the -rowsperstrip option to set the number of rows (scanlines) in  each  strip
       of  data in the output file.  By default, the output file has the number of rows per strip
       set to a value that will ensure each strip is no more than 8 kilobytes long.

       The -append option tells pamtotiff to add images to the existing output file (a TIFF  file
       may contain multiple images) instead of the default, which is to replace the output file.

       -append was new in Netpbm 10.27 (March 2005).

NOTES
       There  are  myriad variations of the TIFF format, and this program generates only a few of
       them.  pamtotiff creates a grayscale TIFF file if its input is a PBM (monochrome)  or  PGM
       (grayscale)  or	equivalent PAM file.  pamtotiff also creates a grayscale file if it input
       is PPM (color) or equivalent PAM, but there is only one color in the image.

       If the input is a PPM (color) file and there are 256 colors or fewer,  but  more  than  1,
       pamtotiff generates a color palette TIFF file.  If there are more colors than that, pamto-
       tiff generates an RGB (not RGBA) single plane TIFF file.  Use  pnmtotiffcmyk  to  generate
       the cyan-magenta-yellow-black ink color separation TIFF format.

       The number of bits per sample in the TIFF output is determined by the maxval of the Netpbm
       input.  If the maxval is less than 256, the bits per sample in the output is the  smallest
       number  that  can encode the maxval.  If the maxval is greater than or equal to 256, there
       are 16 bits per sample in the output.

   Extra Channels
       Like most Netpbm programs, pamtotiff's function is mostly undefined if the  input  is  PAM
       image with tuple type other than BLACKANDWHITE, GRAYSCALE, or RGB.  Most of the statements
       in this manual assume the input is not such an exotic PAM.  But there is a little  defined
       processing of other PAM subformats.

       pamtotiff assumes any 1 plane PAM image is BLACKANDWHITE or GRAYSCALE (and doesn't distin-
       guish between those two).

       pamtotiff assumes a PAM with more than 1 plane is of tuple type RGB except with that  num-
       ber  of planes instead of 3.  pamtotiff doesn't really understand red, green, and blue, so
       it has no trouble with a 2-component or 5-component color space.  The TIFF  format  allows
       an  arbitrary number of color components, so pamtotiff simply maps the PAM planes directly
       to TIFF color components.  I don't know if the meanings of 5 components in  a  TIFF  image
       are standard at all, but the function is there if you want to use it.

       Note that pamtotiff may generate either a truecolor or colormapped image with an arbitrary
       number of color components.  In the truecolor case, the raster has that number of  planes.
       In  the	colormapped case, the raster has of course 1 plane, but the color map has all the
       color components in it.

       The most common reason for a PAM to have extra planes is when the tuple type is xxx_ALPHA,
       which  means the highest numbered plane is a transparency plane (alpha channel).  At least
       one user found that a TIFF with an extra plane for transparency was useful.

       Note that the grayscale detection works on N-component colors, so if  your  planes  aren't
       really color components, you'll want to disable this via the -color option.

   Multiple Passes
       pamtotiff reads the input image once if it can, and otherwise twice.  It needs that second
       pass (which happens before the main pass, of course) to analyze the colors  in  the  image
       and generate a color map (palette) and determine if the image is grayscale.  So the second
       pass happens only when the input is PPM.  And you can avoid it then by specifying both the
       -truecolor and -color options.

	If the input image is small enough to fit in your system's file cache, the second pass is
       very fast.  If not, it requires reading from disk twice, which can be slow.

       When the input is from a file that cannot be  rewound  and  reread,  pamtotiff  reads  the
       entire input image into a temporary file which can, and works from that.  Even if it needs
       only one pass.

       Before Netpbm 9.21 (December 2001), pamtotiff always read the entire  image  into  virtual
       memory and then did one, two, or three passes through the memory copy.  The -truecolor and
       -color options did not exist.  The passes through memory would involve page faults if  the
       entire image did not fit into real memory.  The image in memory required considerably more
       memory (12 bytes per pixel) than the cached file version of the image would.

   Resolution
       A Tiff image may contain information about the resolution of the image,	which  means  how
       big  in real dimensions (centimeters, etc.) each pixel in the raster is.  That information
       is in the TIFF XRESOLUTION, YRESOLUTION, and RESOLUTIONUNIT tags.  By  default,	pamtotiff
       does not include any tags of these types, but you can specify them with the -tags option.

       There  are  also  options  -xresolution,  -yresolution, and -resolutionunit, but those are
       obsolete.  Before -tags existed (before Netpbm 10.31 (December 2005), they were	the  only
       way.

       Note  that  the	number	of  pixels in the image and how much information each contains is
       determined independently from the setting of the resolution tags.  The number of pixels in
       the output is the same as in the input, and each pixel contains the same information.  For
       your resolution tags to be meaningful, they have to consistent with whatever  created  the
       PNM input.  E.g. if a scanner turned a 10 centimeter wide image into a 1000 pixel wide PNM
       image, then your horizontal resolution is 100 pixels per centimeter, and if your  XRESOLU-
       TION  tag says anything else, something that prints your TIFF image won't print the proper
       10 centimeter image.

       The value of the XRESOLUTION tag is a floating point decimal number that  tells	how  many
       pixels there are per unit of distance in the horizontal direction.  -yresolution is analo-
       gous for the vertical direction.

       The unit of distance is given by the value of the RESOLUTIONUNIT option.   That	value  is
       either  INCH, CENTIMETER, or NONE.  NONE means the unit is arbitrary or unspecified.  This
       could mean that the creator and user of the image have a separate agreement as to what the
       unit  is.   But	usually, it just means that the horizontal and vertical resolution values
       cannot be used for anything except to determine aspect ratio (because even though the unit
       is arbitrary or unspecified, it has to be the same for both resolution numbers).

       If  you don't use a -tag option to specify the resolution tag and use the obsolete options
       instead, note the following:

       o      If you don't include an specify -xresolution, the Tiff image does not contain hori-
	      zontal  resolution  information.	 Likewise for -yresolution.  If you don't specify
	      -resolutionunit, the default is inches.

       o      Before Netpbm 10.16 (June 2003), -resolutionunit did not exist and  the  resolution
	      unit was always inches.

HISTORY
       pamtotiff  was  originally  pnmtotiff  and  did not handle PAM input.  It was extended and
       renamed in Netpbm 10.30 (October 2005).

SEE ALSO
       tifftopnm(1) , pnmtotiffcmyk(1) , pamdepth(1) , pamtopnm(1) , pam(1)

AUTHOR
       Derived by Jef Poskanzer from ras2tiff.c, which is Copyright (c) 1990 by Sun Microsystems,
       Inc.  Author: Patrick J. Naughton (naughton@wind.sun.com).

netpbm documentation			 03 December 2008		 Pamtotiff User Manual(0)


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