Provided by: libtk-img-doc_1.4.7+dfsg-2_all bug

NAME
       img-jpeg - Img, Joint Picture Expert Group format (jpeg)


SYNOPSIS
       package require Tk

       package require img::jpeg  ?1.4?

       image create photo ?name? ?options?

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DESCRIPTION
       The  package  img::jpeg  is a sub-package of Img. It can be loaded as a part of the complete Img support,
       via package require Img, or on its own, via package require img::jpeg.

       Like all packages of Img it does not provide new commands, but extends the existing Tk command  image  so
       that  it  supports  files  containing raster images in the Joint Picture Expert Group format (jpeg). More
       specifically img::jpeg extends Tk's photo image type.

       The name of the new format handler is jpeg.  This handler provides new additional configuration  options.
       See section JPEG OPTIONS for more detailed explanations.

       All of the above means that in a call like

       image create photo ?name? ?options?

       [1]    Image data in jpeg format (options -data and -file) is detected automatically.

       [2]    The format name jpeg is recognized by the option -format.  In addition the value for the option is
              treated as list and may contain any of the special options listed in section JPEG OPTIONS.


JPEG OPTIONS
       The handler provides six options, two effective when reading from a JPEG image, and five influencing  the
       writing of such. One option is usable for both reading an writing.

       -fast  This option is for reading from JPEG data. It usage activates a processing mode which is fast, but
              also provides only low-quality information.

       -grayscale
              This option can be used for both reading and writing of JPEG data. Usage  of  this  option  forces
              incoming images to grayscale, and written images will be monochrome.

       -quality n
              This  option is for writing JPEG data. It specifies the compression level as a quality percentage.
              The higher the quality, the less the compression. The nominal  range  for  n  is  0...100.  Useful
              values are in the range 5...95. The default value is 75.

       -smooth n
              This option is for writing JPEG data. When used the writer will smooth the image before performing
              the compression. Values in the 10...30 are usually enough. The default is 0, i.e no smoothing.

       -optimize
              This option is for writing JPEG data. It usage causes the writer to  optimize  the  huffman  table
              used to encode the jpeg coefficients.

       -progressive
              This option is for writing JPEG data. It usage causes the creation of a progressive JPEG file.


SEE ALSO
       img-bmp,  img-dted, img-gif, img-ico, img-intro, img-jpeg, img-pcx, img-pixmap, img-png, img-ppm, img-ps,
       img-raw, img-sgi, img-sun, img-tga, img-tiff, img-window, img-xbm, img-xpm


KEYWORDS
       image handling, jpeg, tk


COPYRIGHT
       Copyright (c) 1995-2009 Jan Nijtmans <nijtmans@users.sourceforge.net>