Unless using a specialist service it may be that your best bet for a high quality digital copy is to either scan the slides yourself or project them on a screen and photograph them with a good digital camera.
Tim
>
Yes, I agree. I remember the days when you used to be able to just take your own SCSI hard disk (before USB even existed) into the better places and they'd put your data on that, but those are long gone :-) They should still do CD/DVD/USB-stick, though, and I'd pick USB any time over any kind of optical media.
It's not just longevity of the media itself if placed in storage*, though; optical media's quite fragile during routine handling (e.g. prone to scratches), and I've seen lots of cases where media will read on some drives and not others - i.e. given media that can be read now on a current drive, there seems to be no guarantee that it could be read in a few years on whatever drive the owner happens to have then.
Oh, I saw one drive (manufactured circa 2005) recently where the rubber hub ring had decayed and gone sticky - I've seen that in the pinch rollers for old tape transports a lot, but it's the first time I've seen it on a DVD drive. Time will tell whether it's a problem that's going to become more common or not. It took some major dismantling of the drive to free the disc from the transport mechanism.
Agreed. And keep at least two digital copies, preferably on different types of media, and 'refresh' those copies onto current-generation technology as time goes on.
cheers
Jules
... or they'll scan to JPEGs as normal and then convert to TIFF as a final step, by which time the damage has already been done.
I'd suggest avoiding any kind of high street store - go to a proper reprographics place who should be able to handle this properly (and IME may well be cheaper too)
Yes, I tend to keep things in four formats - hi-res originals, medium-res JPEG for release via the 'net, low-res JPEGs for viewing on screen, and then thumbnails for overviews.
(I remember a decade ago on a project we were dealing with images that were something like 12000x12000 pixel res, scanned from aerial photos - fun for the hardware of the day, although I suppose that's a bit less taxing now)
cheers
Jules
... although I seem to recall a time where there were patent issues involving LZW, which meant that various tools came with LZW support disabled or missing entirely; have those all been resolved such that it's free to use again?
Five -
The highres original TIFF as scanned before cropping and level adjustment, the highres leveled and adjusted TIFF,
Anna - buy a scanner and D I Y ? [g]
Some misunderstanding on your part. JPEGs are compressed using lossy compression. You're pretty much at the whim of the person saving the JPEG what quality you get. BMP is Microsoft's format for saving files in a lossless format. It's OK but the files are huge.
Scaling any bimapped image is problematical. Generally all formats can be reduced in size without loss of quality. No format can be increased in size without severe loss of quality. If you have a decent graphics application such as Photoshop you may choose to increase the size of a bitmapped image and use on of a number of techniques designed to make the loss of quality less obvious.
Given a free choice I would specify TIFF rather than JPEG or BMP provided that the size of the image file was not an issue. Obviously you want the resolution to be as high as possible. An alternative would be to demand Photoshop (PSD) format but only if you have Photoshop yourself. After that, PNG is IMO better than BMP offering some compression without loss of quality.
However above everything else you need to specify the actual resolution and size of image that you want, before you specify the file type. The slides need to be scanned at the full optical resolution of the scanner and saved at that resolution. If you settle for JPEG, you must specify that it is saved at the lowest possible compression ratio.
Indeed, you can't invent detail that wasn't there in the first place! But up-scaling an image doesn't mean you will 'see the pixels' as some people believe; if done properly it won't be 'pixellated' but of course it will be more or less 'blurred'.
Richard.
Hmm, I can see your thinking, but the 'adjustment' step might be redundant - or rather the need to store its output; just leave a "this is what I need to do before resolution changes" comment in the original TIFF, and work off the comments if you ever need to re-generate lower-resolution copies...
I don't think "consumer" stuff has anything like the quality of commercial-grade scanners, though - even if they quote high DPI figures, it's usually via a lot of magic interpolation and the actual 'raw' scan resolution isn't very high. (Went through this with some DEC microfiche a few years ago - the cheapest scanner that could do it justice cost over ten grand)
cheers
Jules
messagenews: snipped-for-privacy@l11g2000yqb.googlegroups.com...
Now you will have to explain that just to get yourself out of the hole.
I've never lost a hard drive to magnetic decay, it's always electronics fails or head crashes. These are of course catastrophic - you lose the whole disc.
Multiple heterogeneous storage on dispersed sites is the safe way to go.
Andy
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I suggest you 'phone a friend or ask the audience.
Or simply look up the definition of image compression,
MBQ
My local sells 1TB external HDDs for £57 + ATM
large enough for you?
messagenews: snipped-for-privacy@v31g2000yqm.googlegroups.com...
messagenews: snipped-for-privacy@l11g2000yqb.googlegroups.com...
I don't need to look up anything its you that is making a claim that you need to explain. Its pointless saying google it as it is you that is making the claim and I have no idea what you are trying to claim so I suggest you explain it.
Data compression like LZW is as I said something you can apply to any data and has nothing to do with images. Jpep, mpeg, etc are image compression and can't be applied to data.
Now what were you trying to say again or are you just arguing because you are bored?
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You just have no idea. period.
Images are just data.
It's not suitable for all images, either.
If you don't mind the data suffering loss of information after being compressed/uncompressed through a lossy scheme, then you can use whatever algorithm you like. Digital data that must be preserved bit accurate is a special case of "data". There are many forms of data that contain sufficient redundancy to be useful after consideralble loss of information.
Whether you compress an image with a lossy or lossless algorithm you are still compressing it (usually to facilitate storage or transport).
You seem to be confusing with audio compression, which is what the BBC do to Radio 3, so you cal listen to it in your car, not to make it easier to store or transmit.
MBQ
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messagenews: snipped-for-privacy@v31g2000yqm.googlegroups.com...
messagenews: snipped-for-privacy@l11g2000yqb.googlegroups.com...
So explain and make yourself feel better.
They are a subset of data, they are organised data and can be compressed using *image* compression.
Why do you think stating the obvious is going to help your case? Just explain what this special compression is that you are an expert in that I don't have a clue what you are talking about is? At least I will then be able to look it up.
You really are scraping the bottom trying to bring yet another subset of data into the argument. Are you going to suggest MP3 compression works on images now? Maybe you think LZW works well on audio, it is just data.
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They can. but they make assumptions about its nature, that lead to loss of information. In a picture, that means slight fractal patterns around detail.
They are not 'lossless' compression.
the other algorithms are. Ultimately compression has to 'know' something about what its compressing to be of any use. Either it will remove detail it thinks is not important, or it wont be able to compress.
Hmm, Aphex Twin spectrograms...
Don't see why you couldn't mp3-compress an image. Decompressing might be trickier ;)
snipped-for-privacy@l30g2000yqb.googlegroups.com...
Because you are the ome who doesn't seem to understand the obvious. A while ago you implied that using LZW was NOT image compression. now you are telling me I'm stating the obvious when I state that using a lossless algorithm is compression. It makes no difference whether the data represents an image or not.
WTF are you on about now? I never said anything about any special compression. We were talking about TIFF containers being used to hold various types of compressed image. You went off on one claiming that LZW was not image compression. Perhaps you should explain your special definition of image compression that you are an expert in.
If you think MP3 has anything to do with what I said about audio compression on radio 3 than you really do need to go and do some reading. Try starting here
I have no opinion on the merits, or otherwise, of LZW for audio.
MBQ
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