Uploading jpeg makes Imagemagick do high compression

Without doing any resizing, a jpeg that's uploaded using "directory upload" becomes highly compressed, and highly distorted as a result. Both the original resolution and generated resolutions have high compression. Since there's no resizing for the original size, there shouldn't have been any change in compression or image quality.

This is with Imagemagick selected, and with the jpeg not exceeding the set max image size nor max resolution.