<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On Nov 14, 2009, at 1:03 PM, Hal V. Engel wrote:</div><blockquote type="cite"><div>...</div></blockquote><blockquote type="cite"><div>on the new pdftoraster filter to add CM support shouldn't it be capable of <br>doing DeviceN separations if it is supplied a DeviceN output ptofile?</div></blockquote><div><br></div>CUPS raster currently does not define DeviceN color spaces, so there is no way to send DeviceN data to the driver if N > 4.  Adding DeviceN to CUPS raster isn't hard, but so far there has been no need for it.</div><div><br></div><div><blockquote type="cite"><div><font class="Apple-style-span" color="#000000">...</font></div><div>prematched using a DeviceN profile.  What happens now if CUPS gets a PDF spool <br>file that has been prematched to DeviceN?  Does it fail even if the device <br>supports DeviceN and the separations are correct for that device?  Or does it <br>convert it to some other format like CMYK?<br></div></blockquote><div><br></div>That depends on the PDF filter you use.  For Mac OS X, CoreGraphics can't do more than 4 color channels, so I'm not sure what you'd get if you provided a 6 channel color in a PDF file.</div><div><br></div><div><blockquote type="cite"><div><blockquote type="cite"><blockquote type="cite">I'm dubious of sRGB-only command sets for inkjet printers.  It<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">artificially restricts the available gamut, and doesn't work if you<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">use a medium other than that specified by the manufacturer.<br></blockquote></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Like it or not, you're going to see more sRGB/AdobeRGB-only devices in the<br></blockquote><blockquote type="cite"> future, even from Epson. Only the high-end printers will support a DeviceN<br></blockquote><blockquote type="cite"> mode that can be used by third-parties...<br></blockquote><br>Again almost no one here is using the hardware vendor supplied drivers.</div></blockquote><div><br></div>I'm not talking about drivers, I'm talking about hardware.  Most of the HP Deskjet/Photosmart/OfficeJet printers and many of the low-end HP DesignJet printers only support printing using PCL3GUI, which is an sRGB raster pipe. No CMYK or DeviceN path exists for these devices - legacy PCL CMYK data, when supported, is converted to sRGB for printing.  I'm seeing similar paths being taken by recent Canon and Epson printers.</div><div><br></div><div>So, even if you wanted to write your own DeviceN driver for these printers there would be no way to get the data to the printer since they only take sRGB.</div><div><br></div><div>___________________________________________________</div><div><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Monaco; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div>Michael Sweet, Senior Printing System Engineer</div><div><br></div></span><br class="Apple-interchange-newline"> </div> <br></body></html>