On 22 Jul 2005 at 17:10, Joaquim Carvalho wrote: > Yes but those are bad excuses: > - there are 12 bits DVI screens > - for printing the conversion from 8 bits RGB to 8 bits CMYK is worse > than from 12 bits RGB > - on both 8 bit screens and printers the software could do dithering to > show more than 256 levels per channel > - in a few years time these limitations will probably change but people > will be stuck with their 8 bits old pictures
Bad excuses? I have a Windows screen driver that allows 10 bits per pixel (10Bit GigaColour) it's fun to talk about but since virtually all Windows applications (including PS) generate 24 bits pixel for display output it's pretty pointless. And whether 12 bits per colour channel would make make an appreciable visible difference given the dynamics of current display technology is arguable (given the relatively low contrast ratios of even the best TFT displays). I'd be happy to read some practical reviews. RAW camera data may be 12 bits per colour channel but the interpolated file can be delivered at 8 or 16 bits/CC and in a variety of colour spaces. Colour space conversions are in 16 bit/CC precision as far as I'm aware (at least since PS 7 though I'm happy to be proved wrong) and in any case all my photo prints are straight RGB so I don't need to engage in potentially lossy CMYK conversions. Generally dither is only beneficial in print systems without the capability to modulate pixel density. Dither is pointless if it only serves to reduce the print sharpness and acutance. RGB direct to photo paper print systems would not benefit from dither so they don't use it, ink jet print systems can benefit and their drivers generally employ dither of some form. Surprise. Any photographer who currently wishes to ensure that their archived digital images are able to take full advantage of future printing technologies need only save them in an image format which can support 16 bit per colour channel wide gamut colour space. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
