GD image file format[1] is not an "object", just dumb data stored externally, same as PNG, JPG, TIF, etc. I now see the module on CPAN. Not sure if it's worth re-iterating, what I suggested was no JPGs in t folder, because same image file can't be expected to decode to same data. Neither $new->jpeg(50) is reliable:

v5.32.1
2.76
d0116830c00ed65dbebfd53afec1dcd0

v5.16.3
2.49
a26bc180a0f0067e00788dee47975324
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for CoventryCathedral.jpg source, because (1) comment segments are

CREATOR: gd-jpeg v1.0 (using IJG JPEG v90), quality = 50
CREATOR: gd-jpeg v1.0 (using IJG JPEG v80), quality = 50
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respectively, and (2) APP0 segment stores aspect ratio for the former, vs. dots-per-inch resolution for the latter, for no obvious reason. +Of course I meant image coders/decoders.

1: https://libgd.github.io/manuals/2.3.3/files/gd_gd-c.html
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