Use case: bulk watermarking images.

I first generate a standard overlay image:

        my $text_overlay = Image::Magick->new();
        $text_overlay->Set(size=>'400x140');
        $text_overlay->ReadImage('xc:white');
        $text_overlay->Set(alpha=>'Activate');
        $text_overlay->Transparent(color=>'white');
        
        my $err=$text_overlay->Annotate(text=>"OverlayText",
                        'pointsize'  =>14,
                        'font'       => 'AvantGarde-DemiOblique',
                        'geometry'   => "+20+20",
                        'fill'       => 'black',
                        'antialias'  => 'true',
            );
[download]

Then I composite that onto a base image

    my $imageTool=Image::Magick->new(magick=>'JPEG');
    my $image=$imageTool->read($image_filename);
    my $err=$imageTool->Composite(
        'image' => $text_overlay,
        'opacity' => '15%',
        'compose' => 'Atop',
        'rotate' => 5, 
        'tile'   => 'true',
    );
[download]

The problem is that this outputs an image with the overlay as just a bunch of blocks http://www.wiglaf.org/aaronm/48572-1.jpg When I run via the convert CLI tool, it does as expected

$ convert -size 400x140 -font "AvantGarde-DemiOblique" -pointsize 14 -
+fill black -antialias -alpha set -transparent white -annotate +20+20 
+"OverlayText"  xc:white white_text.png
$ composite white_text.png 48572-1.jpg -tile -compose Atop -dissolve 1
+5% overlay_test.jpg
[download]

http://www.wiglaf.org/aaronm/overlay_test.jpg

This code worked (the perl code) until sometime in the last 8-12 months, but I don't know of anything that changed on the system. Any thoughts?