Unix/Linux Go Back    


SuSE 11.3 - man page for jpeg (suse section n)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)


jpeg(n) 			     JPEG image manipulation				  jpeg(n)

_________________________________________________________________________________________________

NAME
       jpeg - JPEG querying and manipulation of meta data

SYNOPSIS
       package require Tcl  8.2

       package require jpeg  ?0.3.3?

       ::jpeg::isJPEG file

       ::jpeg::imageInfo file

       ::jpeg::dimensions file

       ::jpeg::getThumbnail file

       ::jpeg::getExif file ?section?

       ::jpeg::formatExif keys

       ::jpeg::exifKeys

       ::jpeg::removeExif file

       ::jpeg::stripJPEG file

       ::jpeg::getComments file

       ::jpeg::addComment file text...

       ::jpeg::removeComments file

       ::jpeg::replaceComment file text

       ::jpeg::debug file

       ::jpeg::markers channel

_________________________________________________________________

DESCRIPTION
       This package provides commands to query and modify JPEG images. JPEG stands for Joint Pho-
       tography Experts Group and is a standard  for  the  lossy  compression  of  photographical
       images. It is specified at LINK_HERE.

COMMANDS
       ::jpeg::isJPEG file
	      Returns a boolean value indicating if file is a JPEG image.

       ::jpeg::imageInfo file
	      Returns  a  dictionary  with  keys  version, units, xdensity, ydensity, xthumb, and
	      ythumb. The values are the associated properties of the JPEG image in file.  Throws
	      an error if file is not a JPEG image.

       ::jpeg::dimensions file
	      Returns  the  dimensions	of the JPEG file as a list of the horizontal and vertical
	      pixel count.  Throws an error if file is not a JPEG image.

       ::jpeg::getThumbnail file
	      This procedure will return the binary thumbnail image data, if a JPEG thumbnail  is
	      included	in  file,  and	the  empty  string otherwise. Note that it is possible to
	      include thumbnails in formats other than JPEG although that is not common. The com-
	      mand  finds  thumbnails that are encoded in either the JFXX or EXIF segments of the
	      JPEG information. If both are present the  EXIF  thumbnail  will	take  precedence.
	      Throws an error if file is not a JPEG image.

		  set fh [open thumbnail.jpg w+]
		  puts -nonewline $fh [::jpeg::getThumbnail photo.jpg]
		  close $fh

       ::jpeg::getExif file ?section?
	      section  must be one of main or thumbnail.  The default is main.	Returns a dictio-
	      nary containing the EXIF information for the specified section.  For example:

		  set exif {
		   Make     Canon
		   Model    {Canon DIGITAL IXUS}
		   DateTime {2001:06:09 15:17:32}
		  }

	      Throws an error if file is not a JPEG image.

       ::jpeg::formatExif keys
	      Takes a list of key-value pairs as returned by getExif and formats many of the val-
	      ues  into a more human readable form. As few as one key-value may be passed in, the
	      entire exif is not required.

		  foreach {key val} [::jpeg::formatExif [::jpeg::getExif photo.jpg]] {
		      puts "$key: $val"
		  }

		  array set exif [::jpeg::getExif photo.jpg]
		  puts "max f-stop: [::jpeg::formatExif [list MaxAperture $exif(MaxAperture)]]

       ::jpeg::exifKeys
	      Returns a list of the EXIF keys which are currently understood.  There may be  keys
	      present  in  getExif  data  that are not understood.  Those keys will appear in a 4
	      digit hexadecimal format.

       ::jpeg::removeExif file
	      Removes the Exif data segment from the specified file and replaces it with a  stan-
	      dard JFIF segment.  Throws an error if file is not a JPEG image.

       ::jpeg::stripJPEG file
	      Removes  all metadata from the JPEG file leaving only the image. This includes com-
	      ments, EXIF segments, JFXX segments, and application specific segments.  Throws  an
	      error if file is not a JPEG image.

       ::jpeg::getComments file
	      Returns a list containing all the JPEG comments found in the file.  Throws an error
	      if file is not a valid JPEG image.

       ::jpeg::addComment file text...
	      Adds one or more plain text comments to the JPEG image in file.  Throws an error if
	      file is not a valid JPEG image.

       ::jpeg::removeComments file
	      Removes  all  comments  from  the file specified.  Throws an error if file is not a
	      valid JPEG image.

       ::jpeg::replaceComment file text
	      Replaces the first comment in the file with the new text.  This is merely a  short-
	      cut  for	::jpeg::removeComments	and ::jpeg::addComment Throws an error if file is
	      not a valid JPEG image.

       ::jpeg::debug file
	      Prints everything we know about the given file in a nice format.

       ::jpeg::markers channel
	      This is an internal helper command, we document it for use by advanced users of the
	      package. The argument channel is an open file handle positioned at the start of the
	      first marker (usually 2 bytes). The command returns a list  with	one  element  for
	      each  JFIF  marker found in the file. Each element consists of a list of the marker
	      name, its offset in the file, and its length. The offset points to the beginning of
	      the  sections  data,  not  the marker itself.  The length is the length of the data
	      from the offset listed to the start of the next marker.

LIMITATIONS
       can only work with files cant write exif data gps exif data not parsed makernote data  not
       yet implemented

BUGS, IDEAS, FEEDBACK
       This document, and the package it describes, will undoubtedly contain bugs and other prob-
       lems.  Please report such in the category jpeg of the Tcllib SF	Trackers  [http://source-
       forge.net/tracker/?group_id=12883].  Please also report any ideas for enhancements you may
       have for either package and/or documentation.

KEYWORDS
       comment, exif, image, jfif, jpeg, thumbnail

COPYRIGHT
       Copyright (c) 2004-2005, Code: Aaron Faupell <afaupell@users.sourceforge.net>
       Copyright (c) 2007, Code:  Andreas Kupries <andreas_kupries@users.sourceforge.net>
       Copyright (c) 2004-2007, Doc:  Andreas Kupries <andreas_kupries@users.sourceforge.net>

jpeg					      0.3.3					  jpeg(n)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 07:00 AM.