Sunday, May 11, 2003: On Thursday, November 14, 2002, I published an article at this place "SIGMA Photo Pro improving JPEG output" about an imperfection of the initial SIGMA Photo Pro 1.0 release in the JPEG output configuration.
I'm glad to state that SIGMA has now announced an updated Photo Pro 1.1 release which fixes the discovered JPEG color quality deficiency.
Foveon and SIGMA have chosen to alter the color subsampling parameter from 2x2 (4:2:0) to 1x1 (4:4:4) at half the quality scale (6 to 7), similar to the proven solution used in the Photoshop software. This is OK and easy to use.
While I had rather suggested a more controllable solution with manual parameter selection, I have in the meantime come to the opinion that color subsampling is generally a bad idea for color quality control in JPEG, and that it should better be replaced in the future by a new method with quantization adaption which I am currently working on.
See also my article "Quantization vs. Subsampling".
Here is an image example which I used to test the function of the new software during development:
Lossless crop at 100 % Lossless crop at 100 % Look at fine red and blue color details, particularly the red "o" in "Mobil" in the lower right corner.