User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9b2) Gecko/2007121120 Firefox/3.0b2 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9b2) Gecko/2007121120 Firefox/3.0b2 While comparing the ACID 2 rendering of 3.0b2 to the reference, I noticed a discrepancy in the rendering of the nose. I grabbed screenshots and compared and noticed that the nose appears to be antialiased in the FF rendering but not in the reference rendering. At a normal resolution, the image almost appears to be a pixel's width too small. Reproducible: Always Steps to Reproduce: 1. Execute the ACID 2 rendering 2. Compare to the reference rending image I reviewed the technical guide on the ACID2 test but did not see anything immediately that covered this in this level of detail. My understanding was that, other than font metrics, etc., that the reference rendering was to be an absolute pixel by pixel match.
Acid 2 does not require perfect pixel matching for the nose. See bug 343583 comment 6. (Hixie is the creator of the Acid 2 test.)
Indeed, this was discussed and resolved as invalid in bug 343583 already -> dupe.
Note to Hixie: if you are still in control of the test, please update reference.png to the attachment 294110 [details] one.
The antialiasing of the nose is not defined by CSS; the reference image I posted is no more valid than the one linked in the test.