2002.12.17 21:47 "CMYK JPEG's", by Dominic Smith

2002.12.18 21:55 "Re: CMYK JPEG's", by Dominic Smith

<x-flowed>I thought this all made sense, but after some more experimenting I'm not too sure.

The "inverted" CMYK JPEG's I have display OK in Paintshop 7 and the Windows XP image viewer. OK, so maybe they are being clever and looking at the Adobe tag...

But when I create a CMYK JPEG from scratch using libjpeg (correct data, and presumably no Adobe tag) both apps show it as negative.

This makes me suspect that, rather than being clever these apps have adopted the Adobe polarity as a default (either deliberately or accidentally). If so, the situation look pretty hopeless :(

Just in case I have made a silly mistake and got everything the wrong way around, does anyone have a sample CMYK JPEG image which they can say for absolute certain is a "white-is-zero" non-Adobe tagged image?