"After those two were installed...". Just to be sure, you meant "After those two and Image::Magick were installed...", right?

Does a simple GD program like the one at the top of the perlpod documentation of GD work? I.e. that one:

            use GD;

           # create a new image
           $im = new GD::Image(100,100);

           # allocate some colors
           $white = $im->colorAllocate(255,255,255);
           $black = $im->colorAllocate(0,0,0);
           $red = $im->colorAllocate(255,0,0);
           $blue = $im->colorAllocate(0,0,255);

           # make the background transparent and interlaced
           $im->transparent($white);
           $im->interlaced('true');

           # Put a black frame around the picture
           $im->rectangle(0,0,99,99,$black);

           # Draw a blue oval
           $im->arc(50,50,95,75,0,360,$blue);

           # And fill it with red
           $im->fill(50,50,$red);

           # make sure we are writing to a binary stream
           binmode STDOUT;

           # Convert the image to PNG and print it on standard output
           print $im->jpeg;
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Name it gdtest.pl and test that with

gdtest.pl > test.jpg
xzgv test.jpg
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Use any picture-viewer or a browser to view the jpeg if you don't have or can't use xzgv,