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On 9/30/03 2:15 AM, "Bill Wardwell wrote in reply to Chuck Miller" : > Yes, RGB images can cause errors in making the PDF. I have never tried to > identify the technical reason for this, but have seen it happen anytime an > image is left in RGB instead of CMYK. You need to check all images in > Photoshop before sending the files, or use a diagnostic program such as > Pitstop to catch and correct RGB's. Other possible outcomes for images left > in RGB include no image where the image should be and black images instead > of color. If you get into another situation where you cannot run a page and > no one is around to help troubleshoot, try this long, but useful way of > getting the page out: in Quark, export the page as an EPS, drop it into > Distiller to make a PDF, then save the file as an EPS and place it back onto > the Quark page. It's a lot of work, but it can get you out of a jam until > you can find the person who gave you hte RGBs. RGB is perfectly allowable in PDF files - in fact, this is the preferred method of exchange in PDF/X-3 workflows when PDF files are exchanged as the type of RGB to CMYK conversion is communicated by placing rendering intent color management profiles inside the PDF file. RGB images in PDF files (or PostScript for that matter) do not really cause errors unless you process them in some RIP without using some manner to convert them to CMYK that is acceptable. Most modern RIPs offer RGB to CMYK conversions identical to the method used in Adobe Photoshop using ICC Profiles. Should you want personally to control RGB to CMYK conversions so that you have a PDF that is entirely CMYK (perhaps you may want to send the PDF to someone with a RIP that does not have RGB to CMYK conversion capabilities) there are several options. One method (of course) is to manually convert all the image files using Photoshop, re-import the files into Quark and then print to Distiller (either using the Quark 'export to PDF' or printing to PostScript and then Distilling) This is quite labor intensive, and frankly, a waste of time (I will assume you are a newspaper and have tight deadlines) Because this is such a common issue, several independent software developers in the prepress market have developed several Adobe Acrobat compatible Plug-ins that offer a way to convert all RGB images AND objects (type, rules, etc) to CMYK. http://www.enfocus.com/ http://www.apago.com/ http://www.quite.com/ http://www.callas.com/ Many people use a server based products to do RGB to CMYK conversions in a more automated form - Enfocus offers a product named Enfocus Pitstop Server that can do this - just drop any PDF file into a watched folder and this product can find any an all RGB items and convert them using the same method as Photoshop. Quite software offers "RGB be Gone" in its Quite a box of tricks product. Also, there are several Quark preflight XTensions (and PDF preflight plug-ins) that can automatically examine and report if a Quark Page or a PDF file has RGB images in them. Hope this helps. ===================== Cheers, Michael Jahn 1104 Esplanade Suite 102 Redondo Beach California 90277 Home office : 310 540 6950 Fax: 310 540 8369 ===================== To change your subscription: http://www.pdfzone.com/discussions/lists-pdf.html
