--- Jon Noring <jon@noring.name> wrote:
But I do believe that those who are submitting scans to DP should seriously consider doing all scans at 600 dpi full color (especially if the scans can be done without page distortion such as if the book is chopped and run through a sheet-feed scanner), and then resample them to 300 dpi (bitonal or greyscale) for submission to DP. Backup the original master scans in lossless form until they can be donated to a future page scan archive. Just some thoughts..
Comments?
Obviously 600DPI full colour looks better than 300DPI bitonal, but this extra quality comes at a high price. Personally, moving from one to the other would not happen until someone buys me a faster scanner, a faster computer, a new large hard disk, and pays me for the extra time it will take me to scan and process the material even with this upgraded equipment. Even then, the high quality scans will never get off my computer unless you buy me a faster internet connection. Even if some people do decide to make high resolution masters, there's little need to make colour scans of black-and-white originals. Grayscale, maybe, but all a colour scan will show you is how yellowed the paper is. You also blithely say 'backup the original master scans', perhaps ignoring just how large lossless full-colour 600DPI scans are. Because I've been scanning for OCR, I can store the over 900 items I've scanned for DP on my hard disk (the folder takes up a little over 33 GB). A single large and long book scanned at 600DPI full-colour could end up taking up that much space by itself... and I don't particularly want to have to burn multiple DVDs every single time I scan something (ah yes, you'll need to pay for the DVD recorder and media). In case you think this is hyperbole, I've just tested out the difference in size and speed, scanning a page of a quarto work (Lloyd's Encyclopaedic Dictionary) using my trusty Epson 1660: 300DPI bitonal: 10 seconds (plus 1 second to save the PNG), 216 KB. 600DPI full-colour: 58 seconds (plus another minute to save the PNG), 42.2 MB. There are 770 pages in this volume (which is one of seven). Assuming these times and sizes are indicative of the average (and it's an average page from the text), and allowing 8 seconds after each page to set the next scan going, scanning at 300DPI bitonal would take a touch over 4 hours without a break, and take up 162 MB. Scanning at 600DPI full-colour without a break would take 25 1/4 hours, and take up *31 GB*. -- Jon Ingram __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com