从没有外部库的php上的imagecreatetruecolor()创建的jpegs中删除元数据

On my website, I create images at 69% quality with the image GD library. It attaches the following meta-tag into each image I create:

"CREATOR: gd-jpeg v1.0 (using IJG JPEG v62), quality = 69"

Because my website has several hundred thousand JPEG images, people would be downloading at least 30MB of nonsense just to see every pic.

I want to somehow successfully erase this metatag and all other unnecessary junk in the JPEG files without resorting to any more libraries. Even some binary solution would be good if I can find one.