JPEG to JP2 result in much bigger file size

[cachila]

Hello,

I'm pretty new to ImageMagick and I'm building a service where anyone can upload a JPEG file and automatically convert it to a lossless JP2 in order to save a smaller file.

I'm using the default command posted at https://imagemagick.org/script/jp2.php

command convert wizard.jpg -quality 0 wizard.jp2

but the result was a much larger jp2 file.

Is there any command or options to make this work as expected? supposedly JP2 files are much smaller than JPEG.

convert -version
Version: ImageMagick 7.0.8-21 Q16 x86_64 2018-12-28 https://imagemagick.org
Copyright: © 1999-2019 ImageMagick Studio LLC
License: https://imagemagick.org/script/license.php
Features: Cipher DPC HDRI Modules
Delegates (built-in): bzlib freetype jng jp2 jpeg lcms ltdl lzma png tiff webp xml zlib

Thanks in advance