img-jpeg(n) img-jpeg(n)

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

SYNOPSIS
       package require TTkk

       package require iimmgg::::jjppeegg  ??11..33??

       iimmaaggee ccrreeaattee pphhoottoo ?name? ?options?


DESCRIPTION
       The  package  iimmgg::::jjppeegg  is a sub-package of IImmgg. It can be loaded as a
       part of the complete Img support, via ppaacckkaaggee rreeqquuiirree IImmgg,  or  on  its
       own, via ppaacckkaaggee rreeqquuiirree iimmgg::::jjppeegg.

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

       The name of the new format handler is jjppeegg.  This handler provides  new
       additional  configuration  options.  See  section JJPPEEGG OOPPTTIIOONNSS for more
       detailed explanations.

       All of the above means that in a call like

       iimmaaggee ccrreeaattee pphhoottoo ?name? ?options?

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

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

JJPPEEGG OOPPTTIIOONNSS
       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.

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

       -ggrraayyssccaallee
              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.

       -qquuaalliittyy n
              This option is for writing JPEG data. It specifies the  compres-
              sion  level as a quality percentage. The higher the quality, the
              less the compression. The nominal range for n is 00...110000. Useful
              values are in the range 55...9955. The default value is 7755.

       -ssmmooootthh n
              This  option is for writing JPEG data. When used the writer will
              smooth the image before performing the  compression.  Values  in
              the 1100...3300 are usually enough. The default is 00, i.e no smooth-
              ing.

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

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

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

KKEEYYWWOORRDDSS
       image handling, jpeg, tk

COPYRIGHT
       Copyright (c) 1995-2003 Jan Nijtmans 



Img                                   1.3                          img-jpeg(n)