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| Thread ID: 26719 | 2002-11-03 21:27:00 | Scanning results disappointing, advice welcomed | Billy T (70) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 95713 | 2002-11-03 21:27:00 | Hi Team I have an HP5100C scanner and from time to time I need to scan glossy images such photographs, or coloured images with plain white backgrounds . I have two problems with the resulting scan image quality: Firstly, I find that scans of photos have image degradation due to what appears to be reflections from the glossy surface . This produces watermark effects with coloured flecks/noise in the background . Matt images scan much better so I have assumed the defining factor is the gloss surface . Secondly, if I scan a coloured image (usually from a paper source, either commercially printed or from an inkjet colour print) plain white areas are rendered with a textured effect as if the scanner is picking up surface texture and magnifying it . Prints made from the scanned image then reproduce with a dirty greyish-yellow background which detracts from what is otherwise a good quality image . I prefer to use 300dpi for detailed images and sometimes use 600 dpi for photos if I can cope with the file size and these effects don't seem to be significantly influenced by scan resolution . Has anybody got any advice on how to overcome these problems? I am not averse to buying a new scanner as I want to convert some 35 mm slides to digital images for easier access and storage but I can't see what I am doing wrong for my current requirements . If this is the way it is, then so be it, but hopefully there must be some image editing software that can clean up backgrounds in the same manner that I can easily clean up monochrome scans . I can't imagine the professionals putting up with degraded images, and they must be scanning glossy photos or images with white backgrounds every day . Advice and ideas welcome . Cheers Billy 8-{) :( |
Billy T (70) | ||
| 95714 | 2002-11-03 22:56:00 | Hi Billy I have got a $139 Microtek 3630 Scanner with MGI Photo Suite software. Mine just scans anything I throw at it, perfectly (well as perfect as I need it) everytime I use it - whether it be 100,300,600 dpi. Has your scanner always had the fault? I would be inclined to get it serviced as it may be a minor fault. Usually those HP scanners produce near perfect results. BALDY:-) |
Baldy (26) | ||
| 95715 | 2002-11-03 23:37:00 | Theres no fault with the scanner, its inherent when taking a scan of a photo. Your going to get a second generation picture no matter what. The best way to resolve your problem is to use your software to balance out the gloss. |
roofus (483) | ||
| 95716 | 2002-11-03 23:47:00 | Hi Billy, in the software that comes with a scanner, when you "aquire" an image there should be an option to apply a "descreen" to reduce Moire fringe effects from glossy surfaces. Have a look at this bible on scanning, scroll down to descreen: http://www.scantips.com/ Lots of useful tips and info there. Sometimes a black sheet of paper instead of the white refecting surface can be helpful if the paper with the image on is thin and/or has printing on the back. |
Terry Porritt (14) | ||
| 95717 | 2002-11-04 03:10:00 | Thanks Terry for your "bible " web page reference. I found it very readable and most helpful regarding basic scanning procedures and in particlar the link to my own scanner. Cheers willbry :) |
willbry (1555) | ||
| 95718 | 2002-11-04 04:41:00 | Thanks for that Terry. The first thing I find is that my scanner came with very basic software indeed. I already had an inkling of this as to get half-pie acceptable results I have had to manipulate the images using facilities found in Kodak Photo Enhancer (came with my cheapie Kodak DC20 camera that was bundled with my Toshiba Libretto mini notebook). Those features are limitedbut were probably good enough for the image quality delivered by the DC20 camera. So, it seems that for starters I need some better software for my scanner, or a new scanner and software. My problems with scanned colour photos or printed material do not look like moire effect and Photo Enhancer provides a dot remover for that function that works well but doesn't help either of my scan quality problems. What are the chances of finding better software from HP that will work with my 5100C? Am I stuck with what I have because the drivers are integrated, or can I separate out drivers and image handling features? Any more clues on the textured background when scanning coloured images on plain white paper? I just checked again with a clean blank white sheet of paper at 75, 150 and 300 dpi, and the results are the same, at all resolutions it looks like the page is heavily textured or covered in sand. Cheers Billy 8-{) :( |
Billy T (70) | ||
| 95719 | 2002-11-04 05:06:00 | You can get the GIMP . . . free . Quite clever software . Your textured background is probably a calibration problem . (Or lack of calibration) . CCD detectors have a base level from each cell, and there is thermal noise added to that . That texture is the base+noise levels for the line sensor, repeated over the image size . Astronomical CCD cameras --even though they are cooled with LN2 or Peltier units-- are always pointed at the white inside of the dome, and that "picture" is subtracted from actual images . My Kodak 6"x4" scanner came with a plain white card for calibration . I can't believe that even the simplest HP software would not have a calibration operation . Have a look at the various options . |
Graham L (2) | ||
| 95720 | 2002-11-05 06:56:00 | Thanks Team I retried the ultra-simplistic calibration feature provided (which has only two steps and requires an almost impossible balancing act between two blocks of horizontal lines and a plain grey block) and this helped a little. I had used it before but the balancing act is difficult to get right. This time I took my glasses off (which blurred the image nicely :^* ) and then balanced the luminance for a uniform grey across the lot. Believe it or not, that worked better than any of my previous attempts. :O There were no other calibration adjustments available so I then got desperate and increased the colour resolution to see what would happen. This improved the white background from dirty grey/yellow to plain light grey and also improved photo scanning quite a bit. The trade-off is a huge increase in file size unfortunately. :( That is a considerable help but I'm not sure that this scanner is delivering the kind of quality I would expect. I used to have an HP4P which was vastly superior but died the death somewhat prematurely. Next time I'll look into the bundled software a little more to make sure I get the tools I need. Cheers Billy 8-{) |
Billy T (70) | ||
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