The IMG [package] by [Jan Nijtmans] provides the handling of several
image formats beyond the standard formats in [Tk].   The formats supported by Img 1.2.4 (the latest stable version) are:

   * [BMP]
   * [XBM]
   * [XPM]
   * [GIF] (with transparency, but without [LZW], due to patent restrictions)
   * [PNG]
   * [JPEG]
   * [TIFF]
   * [postscript]

The Img homepage can be found here: [http://members1.chello.nl/~j.nijtmans/img.html]

Sources available at [SourceForge]:
http://sourceforge.net/projects/tkimg/ 

Img is bundled as part of ActiveState's [ActiveTcl] binary distributions.


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[LV] Does Img work with Tk 8.4 ?

[AK] It should. I remember that I did an experimental build of ActiveTcl against 8.4cvs and the compilation went through without a hitch.

Note: This is about the Img sources in the CVS. Img 1.2.4 most definitely does not compile against 8.4 because of changes in some public API functions of Tk regarding Img handling.

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I often have a need to convert from one graphics format to another.  As
long as I have ActiveTcl around, the chore is easy; all I need is a
script on the order of
    package require Img

    cd /temp

    foreach file [glob *.bmp] {
        set root [file rootname $file]
        set image [image create photo -file $file]
        foreach {format suffix} {JPEG jpg GIF gif PNG png} {
            $image write $root.$suffix -format $format
        }
    }


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[['Would be valuable to compare its capabilities with [Xbit]'s.]]

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'''Capture a window into an image''' (screenshot) (posted by [Mark G. Saye] in [the comp.lang.tcl newsgroup]):
 proc capture {W format file} {
   set image [image create photo -format window -data $W]
   $image write -format $format $file
   puts "capture -> '$file' ([file size $file] bytes)"
   image delete $image
 }

   package require -exact Img 1.2.4

   set top .t
   toplevel $top
   frame $top.f
   pack  $top.f -fill both -expand 1

   label $top.f.hello -text "Hello World"
   pack  $top.f.hello -s top -e 0 -f none -padx 10 -pady 10
   update
   bind $top <Key-x> [list capture $top gif capture.gif]
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Saves a white image only, however ;-(. [Paul Obermeier] has this:
 proc canvas2Photo { canvId } {
    # The following line grabs the contents of the canvas canvId into photo image ph.
    set retVal [catch {image create photo -format window -data $canvId} ph]
    if { $retVal != 0 } {
       puts "\n\tFATAL ERROR: Cannot create photo from canvas window"
       exit 1
    } 
    return $ph
 }
[RS] experimented with this and found that it can convert [canvas], [text] and [listbox] widgets, but not a compound [toplevel]. Hence, the name might better be ''widget2photo''... or, by using default error handlers, be simplified to an [interp] alias:
 interp alias {} capture {} image create photo -format window -data
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''David Easton: 17 Jun 2003'' [Capture a window into an image] extends this to work for a whole [toplevel] window complete with sub-widgets.
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[[ [Category Package] | [Category Graphics] ]]