It seems that both PerlMagick and Netpbm are not pure perl solution,
I could be proved wrong, but I would not expect to find a pure perl
program to convert BMP to JPEG format.
so If I want to make a EXE file(using Perl2EXE etc.) and send to
others, I should send some other DLL/EXE files with it, right?
The original question was that -you- wanted to do the conversion. Now
it seems that you want to equip others (but of unstated skillsets) to
perform the conversion?
In general they could follow the same recipes to download and install
the software, that you would have followed yourself. I'm no great fan
of folks re-packaging existing versions of software (that never get
bugfixes, and stick at a frozen version), even where the terms of use
permit it. Unless of course they have an effective procedure for
supporting the repackaged software.
Do you know any other way to solve this problem?
Sure: set up the converter as a CGI script on your web server and let
them use it.
I just want to convert the JPG files to BMP files,
You originally said the opposite. But these solutions can do either
(and much more).
good luck