This is an extension for Tk-b10 (or later?) which supplies
JPEG format loader for Photo image type.

The sub-directory jpeg is release 5 of the The Independent JPEG Group's (IJG)
free JPEG software with only the addition of a (dubious) Makefile.PL.  

It looks as though it would be fairly easy to add -data loading 
and writing, although the value of saving dithered image as JPEG is 
uncertain.

This package is not distributed with perl/Tk yet as the build process
does not follow a proper MakeMaker mechanism yet.

In particular Makefile.PL in jpeg directory just invokes IJG's GNU-ish
'configure' script. Thus some hand intervention may be required.

  
That said : 

perl Makefile.PL
make 
make test 

Should build it.