Provided by: libtk-img-doc_1.4.16+dfsg1-1build2_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
       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.

       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.

       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 the following options:

       -fast  This  option is for reading from JPEG data. If specified, it 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.  If  specified,  it  causes  the  writer  to
              optimize the Huffman table used to encode the JPEG coefficients.

       -progressive
              This  option  is  for  writing JPEG data. If specified, it causes the creation of a
              progressive JPEG file.


SEE ALSO
       img-bmp, img-dted, img-flir, 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) 1995-2023 Jan Nijtmans <nijtmans@users.sourceforge.net>