Lossless scan over AirPrint

I have an EPSON printer that I use to scan documents. I find that regardless of the file format and target DPI in the AirPrint scanner settings, it comes out with very visible JPEG artifacts, leading me to believe that there is some sort of compression going on within AirPrint. Scanning directly from the printer to a USB with JPEG does not leave artifacts of this magnitude. [Edit: it might be just masked by other noise. See added comparison photo. Or is it actually not JPEG noise, just noise that the AirPrint managed to remove from the background but not around the text?] Is this a problem with AirPrint? Is it possible to scan lossless over AirPrint? Edit: I also tried EPSON's own scanning utility downloaded from the support section of the printer page. Selecting "TIFF" results in a 100MB file with similar magnitude of artifacts. Is this then a problem with how EPSON handles wireless transfer of image? Edit 2: see comparison between three printing methods. TIFF and BMP files are uncompressed. JPEG file are compressed at 94% quality based on output of imagemagick. From left to right: vuescan, canon JPEG to USB thumb drive, AirPrint. All set to 600DPI.