Storing digital photos

Thanks for all the suggestions. What interests me most is that from Sailorbaz and using Irfranview to reduce the size to 100kb. I will be interested to see what the quality looks like and the effort required to do this. May well be acceptable as the vast majority of accumulated photos will only be viewed on a PC. This also allows me to continue to use an automated online data backup service.

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JPEG degredation isn\'t true.

There's no theoretical reason why repeated saving of a JPEG using the same compression factor should degrade the image.

As a practical demonstration, here's an image prepared with the popular Photoshop Elements 2.0 that was modified and re-saved 10 times at compression factor 2 - each orange blob at the top represents a separate load, modify and re-save. There is no difference, even down to pixel level, between the first and the final image, other than where the blobs were added.

Before ... After....

test.jpg
testx.jpg


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Re: JPEG degredation isn\'t true.

sky has changed colour and the water too

<hr width=100% size=1><A target="_blank" HREF=http://www.topcatsail.co.uk>Woof</A>
 
Re: JPEG degredation isn\'t true.

Practical example here
http://graphicssoft.about.com/library/weekly/aa0104jpegmyths.htm

<hr width=100% size=1>Me transmitte sursum, caledoni
 
Re: JPEG degredation isn\'t true.

No - try downloading images and expand, set 24-bit colour then sample individual pixels and check their RGB values. I did about 25 at random across the image --- all identical. (Incidentally the successive saves of the image involved closing and reopening the editor).
 
Re: JPEG degredation isn\'t true.

You want to re write history too? It's a fact, so why go against the grain?

<hr width=100% size=1>Me transmitte sursum, caledoni
 
Rewriting history

Come on BrendanS, just do the check yourself.

In fact, I have now found a few pixels with a slightly changed colour value between the two images. But it is only a small minority, even after 10 resaves. My guess is that those who report rapid degradation have been using crummy editors which short-cut the JPEG algorithm in the interests of speed - or they have switched between editors and/or compression levels.

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Re: Rewriting history

I don't look at pixels though. Maybe you are right single pixels are close or the same as the original. But looking on screen at the picture I see a difference. Maybe I am looking as a photographer, but side by side I see it, I can not believe you can't.

The water has lost so much colour and looks quite washed out, the crispness has gone. you are losing colour in the trees and the sky looks like it was over exposed.

Look at them.

Can I ask a non personal question, how old are you, it might be that your colour definition is fading a bit, I am not insulting you. It is like you hearing range changes as you age maybe your eyes just don't see the difference that is there.

I would also like to see the full sized images zoomed in, I bet the artifacts are very visible then.

FWIW.

Storing digital photographs:

You would never cut your old negatives up to squeeze them into a matchbox so why damage you original photographs by squashing 7000 onto a CD.

Blank CD's come in about 20p each. Store your originals 'out of the camera' put the disk safe. Squash copies and put them all onto a single CD if you want that convenience of having all your albums on one CD. But should you ever want a proper print you have lost your original if you compress further.

Most camera algorithms are excellent. I quite often shoot in RAW or TIFF if I am looking for 'that photo'. They come in at 16MB. The highest quality jpeg is excellent though, and around 2.3MB. I would not go smaller than that.

Do though write 2 CD's for each, mirrored. A scratch and you could lose everything. I actually store my backups on the boat, so the house burning to the ground does not mean losing memories.

<hr width=100% size=1><A target="_blank" HREF=http://www.topcatsail.co.uk>Woof</A>
 
Re: JPEG degredation isn\'t true.

re History rewrite.

A good test would be to do multiple saves of a JPEG of a rotating propeller and compare it to the original one of the propeller locked.

John

<hr width=100% size=1>I am the cat but I am only 6.
 
Re: Rewriting history

little piccies posted on internet are going to show little difference. It's what jpeg is good for. Blown up at full size is what matters, unless piccies always meant for internet consumption

There's no telling some people, who won't listen no matter what.

<hr width=100% size=1>Me transmitte sursum, caledoni
 
Re: JPEG degredation isn\'t true.

Sorry Boatless, the devil made me say it /forums/images/icons/crazy.gif.

John

<hr width=100% size=1>I am the cat but I am only 6.
 
Re: Rewriting history

BrendanS is correct in that JPEGs should never be saved more than once - each repeated compression degrades the image. I would only use JPEGs that have been directly saved from a TIFF file.

If a JPEG is saved more than two or three times "halos" and other interference start to appear around the image, and there is a general loss of definition.

BTW: This does not mean that JPEGs cannot be copied - they can by simply copying the file without opening it.

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Some bad advice given

It is a bad idea to use CD's as a primary means of storing photos. The reason is that CD's quickly deteriorate, and the files will be lost forever within a surprisingly short period.

It is possible to buy CD's of varying quality, there are some "archival" ones that should last longer than the standard CD-R's bought in shops, but even then your data is at peril, the use of better quality materials slows down the ageing process rather than stops it. Many music CD's which are burnt on relatively high quality CD's become unusable as the years pass by. And 'normal' CD-Rs are built of material that degrades quickly even if scratches etc are avoided.

There is no perfect answer to safe storage of digital files, but the best solution I've found, and much more convenient than CD's, is to buy a dedicated hard drive for the storage of images only. I bought a 200GB external hard drive for the purpose, whch cost just over 100 pounds. Of course, hard drives can crash too, but they are usually more easily recoverable, and I also back the hard drive up onto a second storage device.

The other huge advantage of a hard drive is that it is possible to surf quickly among your images without hving to load dozens of relatively slow CD's looking for the image that you're after.

A better solution is to take pictures that may be valuable on film! If needed in digital form, they can then be scanned. Despite what the marketing departments tell you, the quality of film is still much better than digital, and I think will be for quite some time to come, and it is esier to keep it in archivally safe conditions.

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Jeez, give us a break!

If the pixels are giving identical RGB values, then any difference you can see certainly isn't down to my eyesight. More likely your manky old PC screen! ;-)

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Re: Some bad advice given

I have to take issue with you on quoting film against digital. Ok, I will not fight that a quality SLR will take a better picture than any digital at the moment, as long as quality film and glass is used.

But for storage I am going to say it is worse than digital.

Last year I bought a slide / negative scanner to put all the family photographs into digital format so we could all benefit (family that is, not you lot). As many keen photographers my father had shot slides rather than film for the quality and colour available in the 1960's and 70's. There were few pictures that I did not have to alter hue and saturation to fix the failings of the film.

The other issue was the quality of the negative, be it a true negative or slide. Many if not most were starting to deteriorate and required a lot of work to repair. The slides were stored in carousels or in plastic boxes and still suffered. Negatives all had blotches, obviously those just dropped in the front of photograph envelopes suffered most. But even negatives in sealed plastic sleeve's were damaged requiring repair.

I also found that I was unhappy with most older developed photographs, it was not until I started scanning in the negatives I realised how soft a developed photo was and how much the labs cropped from the original.

See here;

02_Salcome_Lifeboat_1987_RAW.jpg

The Salcombe Lifeboat 'Baltic Exchange' this was the condition of the negative after 18 years, I took this shot and the negative had never been out of its wallet.

01_Salcome_Lifeboat_1987.jpg

Cleaned up extensively, but never as good as it should be, I have spent a long time trying to clean the water and I don't think I can ever get it 'right'.

So my advice, is go digital, buy a camera based on the lens, everything else is inconsequential as the CCD chips are all bought in. Though algarythms do change between camera's Canon, Nikon and Olympus all make the best mid range cameras IMHO. You may have to re-write older CD's as the CD breaks down, but if you have backed up, the image will NEVER lose quality.

hope this helps

<hr width=100% size=1><A target="_blank" HREF=http://www.topcatsail.co.uk>Woof</A>
 
Re: Some bad advice given

About storage: slides & negative should only be stored in archivally neutral materials, and in dry conditions. Storing them in ordinary plastic will inevitably lead to deterioration as the chemicals work their way out of the plastics into the slides. A lot also depends on the quality of the original processing: for example, whether all the fixer was properly washed out of negatives.

The problem with backing up CD's as they deteriorate is that then it is already too late. Once they have deteriorated, you can't open them to back them up. ALL the information is lost. I would expect the average CD to last about five years. Some become unreadable much earlier than that. Even a badly kept slide lasts longer than that.

I am not really knocking digital, I think digital is a great thing, and I use it frequently across a range of cameras. But I would only ever take my personal work on film. Despite all that the marketing departments tell you, the quality is still considerably better, even when compared to a 3,500 pound professional digital camera. And it is much easier to keep film in archivally safe conditions. Because I don't want to lose any images, I also scan all of my favourite pictures so that I haev digital copies if the original is damaged or lost, but from time to time I lose the digital copies through failure of the storage device, and have to rescan the original.


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"... the average CD to last about five years"

This seems seriously pessimistic. We've been burning CD's at work for over 6 years now, using no more than what is now the equipment fitted to most home PC's. Material includes photographs as well as other types of data. We have had no reports of even one that has degraded or failed later after initially working successfully, except where it has been obviously damaged. Doubtless it happens eventually, but the average would seem likely to be longer than 5 years.

Of course, it is wise to remember the history of recording over the last century: that no recording medium (or the apparatus to play it) lasts forever. We have to expect to update every so often. I have audio recordings that went from 78 discs -> reel-to-reel tape -> tape cassette -> CD. Sure they have degraded, but they continue to give enjoyment long after the original 78's were broken or lost. If digital technology had been around 50 years ago, the recordings might still be as good as new.
 
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