Commands no reduce size in wondows

[eecanoc789]

Good Morning

I have a doubt, I am executing some commands to reduce the size for images, the commands are:

1. convert original.jpeg -define jpeg:extent=300kb output.jpg
2. mogrify -define jpeg:extent=127kb -path c:\images\out c:\images\*.jpg

I tested both in windows environments but it does not reduce the size just 5%, and I executed this command on Linux environments and it works, those commands only work for linux?

Thanks so much.

[fmw42]

use -quality to reduce the file sizes for jpg