Loss of quality in jpg files

  [DELETED] 14:05 25 Jun 2007

I realise that jpg files are said to lose quality each time they are edited, but do they lose quality each time they are *opened* just to look at? If so, would it work if I do a 'batch convert' to change them all to a *tif file? If so, presumably this would freeze them at their present state of 'quality'?

I want to sort out several thousand photos in my computer, as there are a lot of duplicates, which will involve opening them in windows fax viewer or in Photoshop.

Many thanks.

  [DELETED] 14:10 25 Jun 2007

jpg files should not loose quality each time you open them to look at, if they did mine would be useless by now.

  [DELETED] 14:12 25 Jun 2007

Viewing them will not cause a problem. It is only a problem if you physically edit and then save over the top of the existing file.
If you are concerned, simply mark them all as read only.

  [DELETED] 14:17 25 Jun 2007

Many thanks, both. Do you mean that I will still lose quality if I click on 'save' (which I sometimes do automatically) even if I haven't actually changed them?

Good idea to mark them as 'read only'.

  [DELETED] 14:25 25 Jun 2007

I edit photo's on my PC and have not noticed any lose of quality. You could always save the edited copy under another name and if you are satisfied with it delete the old one.

  [DELETED] 14:33 25 Jun 2007

Yes you will loose quality if you click save or save as. This over-writes the original thus loosing quality. If you only view the photo then click close or exit which will not incur any loss.

  [DELETED] 15:07 25 Jun 2007

The obvious way to this maze is to save originals and work only on 1st copies.
Then if after repeated working particular file[s] 'fades' delete it and make another copy from the master.

  hssutton 15:19 25 Jun 2007

The golden rule of editing images on a pc is, NEVER work on the original file.

Once a file as been saved then reopened, the save command should be greyed out, so you should not be able to select the save command. If you make a modification then "Save As" the quality will be impaired, to a certain extent this impairment can be minimised by using the maximum quality setting in Photoshop this will be setting 12.

If you go the Tiff route this will as you say Preserve the images at their present quality. You will however see a major increase in in file sizes, so consider available storage capacity. Two Jpegs one as master and one as a copy, (Two jpegs will take up far less space than one Tiff) to work on will probably be the better way to go, unless your camera will shoot Tiffs or you decide to go the Raw route

My method is to shoot in "Raw" then convert to Tiff. Both files are then saved to my dedicated photo h/drives. The only time I would convert to Jpg is for posting on the web

  [DELETED] 16:19 25 Jun 2007

Lots of useful information here. Thanks.

I am working on PalaeoBill's 'read only' suggestion. Is it possible to make all the files in a large folder containing other folders and subfolders read only in one go? It doesn't seem to work.

  [DELETED] 16:31 25 Jun 2007

Right click the folder, select Properties, tick Read Only (you may need to click twice or three times, if the box is grey but still clickable it means some files in the folder are already Read Only and some aren't), you should now see a box saying `you have chosen to make the following attribute changes` - make sure you select `Apply changes to this folder, subfolder and files`

  Diemmess 16:35 25 Jun 2007

I'm glad hssutton mentioned increased file size on conversion to TIFF.
It is going to be a factor not only filespace but editing, copying an so on if there is a large number to do.

(soto voce)
"A sense of proportion should be adopted."
I prefer jpgs for most purposes, converting to tiff when I have something very special.
Corel Photopaint can be configured to allow no compression when saving jpgs.
I know a lot of history detail goes at that point, but for family or record snaps it really isn't needed

This thread is now locked and can not be replied to.

Elsewhere on IDG sites

Xiaomi Mi 8 Review

Adobe confirms it’s working on a full Photoshop for the iPad

Apple announces new MacBook Pros for 2018

Qu’est-ce qu’Amazon Prime ?