Author Topic: Tip: Image Quality  (Read 4229 times)

Offline gippeswyc

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Tip: Image Quality
« on: Thursday 06 October 05 17:46 BST (UK) »
This is really an obvious one but one which is easy to forget.

When saving ongoing work always save in a lossless format, ie TIFF or at the very least JPEG with no compression. Only your final piece (assuming it may be loaded here) should have any compression if dictated by the file size constraint.

Sounds obvious but my JPEG compression in PSP is set to around 80-90%. If you forget and keep saving on-going work with compression ON the image will effectively deteriate each time its saved - I know, I've done it  :-\

Offline tomkin

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Re: Tip: Image Quality
« Reply #1 on: Tuesday 11 October 05 14:19 BST (UK) »
Sorry mate,
  I must have missed this posting.Very sound
advice indeed.(and we have all done it)
I always save in Tiff where possible.
 
Thanks for taking the trouble to point it out.
Keep posting any tips you have, That's what
I like about RootsChat.
Tomkin.



Offline 0rinoco

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Re: Tip: Image Quality
« Reply #2 on: Monday 27 April 09 11:56 BST (UK) »
I find PNG an adequate format for editing images. To edit and save in JPEG format will definitely cause detail loss. I store all originals for my website in PNG and only convert copies to JPEG for uploading.
I see quite a few repaired photos on this site that have obviously been worked on in JPEG format, the loss of quality being quite noticeable. Repeated saving in JPEG format can result in excessive detail loss. This does not occur with PNG, as it is loss-less.
Eric
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Offline Gadget

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Re: Tip: Image Quality
« Reply #3 on: Monday 27 April 09 12:35 BST (UK) »
TIF or PSD are perfectly adequate for working with. The problem with PNG is that the file sizes are substantially larger than JPG therefore requesters and restorers have to put up much smaller images to meet the 500kb limit (unless they use something like Imageshack or Photobucket).

Compression is the main problem. I work in PSD  and I only convert to JPG when the restoration is completed and I then upload to Imageshack. I always keep the final PSD, layered image for a few months after.

As has been stated on the Photo Board, time and time again, restoration of an initially highly compressed image will never produce as good a result as uncompressed ones. However, not all members are as adept as some of us with scanners and compression and dpi, etc. and we have to work with what is produced.


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Offline 0rinoco

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Re: Tip: Image Quality
« Reply #4 on: Monday 27 April 09 21:49 BST (UK) »
I'm not saying that members should attempt to upload PNG images, but that the restorers should convert them from JPEG before working on them. I use Reaconvertor or Paint.net
Uploading JPEG will have no effect on the quality of the image. I upload all my website images in this format, as the maximum size allowed by my web host is 2 megabite. Any that are in excess of this size in JPEG format (mainly maps)  I have to split into sections before uploading.
Artus, anywhere UK
Gabb, Glos.
Wathern, Glos.
Littleton, Glos.