Conversion from jpg to pdf, file gets bigger with PerlMagic

[knuno]

I use montage to put together 3 jpg-files to one. The files are each about 300KB, and by using reasonable geometry the resulting jpg file is about 5-600KB. But I want a pdf-file so I do:

Code: Select all

$image = Image::Magick->new;

$image -> Read('16161722_1.JPG', '16161722_2.JPG', '16161722_3.JPG');

$doc = $image -> Montage(geometry=>'800', tile=>'1x3');

$doc -> Write('pres.pdf');

The problem is that the resulting pdf is about 4MB large! But if I let my program write the finished image as a jpg-file and then use a simple convert from bash:
convert pres.jpg pres.pdf
the resulting pdf file is only a few kilobytes larger than the jpg, about 600KB. Are there some options to Write that I'm missing or?

Knut