Image compression / JPEG Quality

There seem to be two places where I can set the 'JPEG quality' of uploaded images:

admin/settings/image-toolkit
admin/settings/imageapi/config

So, question 1) What does each setting do - why are there 2 settings? As far as I can make out, the imageapi setting affects imagefield and imagecache, whilst the other setting effects other uploaded images.

2) More importantly... How can I disable automatic compression of images? I don't want Drupal screwing with my uploaded images. I have spent time and effort compressing my images exactly the way I want them, to optimise the quality and filesize to my needs. However, when I upload one of these images via a cck imagefield, they get compressed again, and either the quality or filesize is completely messed up.

I have tried setting the 'jpeg quality' to 0 or 100%, neither of which disable the compression. with it set to 0, I get the most blocky looking images on the planet. With it set to 100%, I can't see any change in the quality of the images, but the filesize increases massively - 3 or 4 times in some cases.

The best I have found so far is to set it top about 95%, where I see only a small change in filesize and quality. This is less than ideal. Is there really no way to disable image tampering? I think that users really should be able to decide for themselves if they want Drupal interfering or not.