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willbry
31-07-2004, 04:55 PM
Not having jetstream I find that when I send digital images[jpeg] via the net to a photo lab overseas for processing and printing it can take virtually all day and my provider keeps cutting me off. The image files vary in general between 700 and 1200 kbs in size.
My question - if I compress these images to say 50% to speed up the process will the prints be markedly poor in quality? I'm not looking for fantastic results but would be happy with "reasonable" snaps if I could cut down the time. If 50% compression is too drastic what level would give me satisfactory results?
{ To avoid the obvious replyI, know I can take my flash card or a CD to have it done locally but these are to be fowarded overseas , processed, and the prints posted, locally to a particular person. I won't see them. Incidentally I get 6X4's done too for only 15p each,
thanks willbry

kiki
31-07-2004, 06:15 PM
Get a copy of WinRAR and RAR the good quality files before sending them.

willbry
01-08-2004, 03:46 PM
Thanks kiki for your suggestion. Will see what they have to offer and how much to buy.
willbry

Graham L
01-08-2004, 04:17 PM
You might find that the JPG files "compressed" with RAR are actually bigger than the original JPGs. :D JPG is already a compressed format. There is very little redundancy in JPG files. Redundancy is what compression gets rid of.

Life is like that. :_| :D

willbry
01-08-2004, 04:58 PM
Looks like it Graham! Seems as if I'm back to square one. Yhanks for your comment.
willbry

caffy
02-08-2004, 12:34 PM
> You might find that the JPG files "compressed" with
> RAR are actually bigger than the original JPGs. :D
> JPG is already a compressed format.

What about using Winzip? does zipping make the photo sizes any smaller?

R2x1
02-08-2004, 01:05 PM
> What about using Winzip? does zipping make the photo sizes any smaller?

Same problem as Rar, for the same reason. The file is compressed by jpg, there is no surplus or redundant bits left to shrink. A jpg will normally be smaller than either win or rar files, because it is a "lossy" compression method and will sacrifice detail and fidelity to acieve a small file, whereas zip and rar files are lossless and will put accurate restoration of the data (or picture) ahead of minimum size. Horses for courses I suppose.
R2

tweak\'e
02-08-2004, 01:14 PM
i would start by cutting down the resolution for the pics. try setting quality to 80%. if still to big just redo them at 80% again and it will drop them down in size and quailty another notch. as far as final quailty goes you will have to print some out and see.

R2x1
02-08-2004, 01:15 PM
Possibly an acceptable method of reducing the file size, is to reduce it at source, re-size your images to 6"x4", and with a resolution of 100dpi. If you can rduce the colour depth, that will drop file sizes quite markedly in some instances, also select "optimised" colours, and you can get quite marked reduction at times. You have to judge if the image quality is acceptable, but a commercial printing shop will normally achieve quite good results from apparently mediocre jpg files. Another reason for the low speed sending; upload speeds are markedly slower than download speeds on dial-up connections.
R2

willbry
02-08-2004, 06:20 PM
Thanks guys for all your comments.You've given me plenty to think about

Cheers