[Therion] Progressive coded JPG files??

[Bill Gee]

Hi Olly -

Thanks for the information.  I think it raises some new questions.

If tkimg is required for both PNG and JPG, then why do PNG files work 
and JPG do not?  If I have tkimg, then both should work, and if I do not 
have it then neither should work.  Is that correct?

How can I tell which versions of tcl have tkimg installed?  If tkimg is 
not present, will xTherion then show an error like it does when bwidget 
is missing?

Looking at the code for xTherion, I see line 27254 which has "package 
require Img".  Is that the line where tkimg is loaded?

I have never taken steps to install either bwidget or tkimg specifically 
for Tk/TCL.  I have only used the RPM packages from the Fedora 
repository.  Here are the packages I have installed:

bgee at main2:~$ rpm -qa | grep tkimg
tkimg-1.4.16-4.fc42.x86_64

bgee at main2:~$ rpm -qa | grep bwidget
kf5-kjobwidgets-5.116.0-3.fc42.x86_64
bwidget-1.10.1-1.fc42.noarch
kf6-kjobwidgets-6.17.0-1.fc42.x86_64

bgee at main2:~$ rpm -qa | grep tcl
tcl8-8.6.15-10.fc42.x86_64
tcl-9.0.0-7.fc42.x86_64


===============
Bill Gee

On 8/25/25 16:49, Olly Betts wrote:
> On Mon, Aug 25, 2025 at 10:10:32AM -0500, Bill Gee wrote:
>> According to this, specifying "-file $ffname" will load the image using
>> whatever format handler is registered for that type.  Tk includes by default
>> handlers for GIF and PPM/PGM formats.  That is why PNG images still work.
> 
> Note PNG is a completely different format to PPM/PGM (and also to GIF).
> 
> AIUI it you need tkimg to get support for both PNG and JPG.
> 
>> So what is the deal?  What does wish really do?  Did the set of default
>> image handlers change between wish 8.6 and 9.0?
> 
> "wish" is a windowing Tcl shell.
> 
> My guess is you have tkimg installed for Tcl 8.6 but not for 9.0 (like
> how you had bwidget installed for 9.0 but not 8.6 until you hacked
> around that by adding a symlink),
> 
> Cheers,
>      Olly