Naked Science Forum

Non Life Sciences => Geek Speak => Topic started by: neilep on 06/02/2009 11:50:32

Title: Why Do Thumbnails Of Edited Pictures Retain The Original Information ?
Post by: neilep on 06/02/2009 11:50:32

I don't know if this is just a peculiarity of my ancient crappy laptop (soon to replaced by a desktop..thanks Mummy !!)

But when I crop a picture, why does the thumbnail image of it remain as the original ?...Even more extraordinary is that on some other pictures I have edited, the thumbnail is a completely different photo !!...I have three cropped and edited pictures of rings (we make them ewe know !)...and the thumbnails of them are all the same picture of another ring !

So, why does this thumbnail hostility happen ?

Title: Why Do Thumbnails Of Edited Pictures Retain The Original Information ?
Post by: RD on 06/02/2009 13:15:07

I often use the free GIMP photo editing programme.
When an image is edited in GIMP (2.6.5) its old thumbnail is only displayed for a fraction of a second before it is updated.

http://en.wikipedia.org/wiki/GIMP

Title: Why Do Thumbnails Of Edited Pictures Retain The Original Information ?
Post by: LeeE on 06/02/2009 13:24:11

It's because of poor software design/implementation.

Title: Why Do Thumbnails Of Edited Pictures Retain The Original Information ?
Post by: Vern on 07/02/2009 17:54:49

If you're viewing folder contents as thumbnails your computer makes a file of the thumbnails the first time through; it then gets the folder contents from that file next time in. The file may be called something like thumb.jbf or such. If you delete that file, your computer will remake it with the latest image data.

Title: Why Do Thumbnails Of Edited Pictures Retain The Original Information ?
Post by: Ultima on 26/02/2009 00:54:36

As vern said, this is generally known as "caching" and is the cause of all sorts of problems that are similar to this. However, it is poor implementation too, since the file browser could just see that the file has been updated since the thumbnail cache was created and make you a new thumbnail!  [:-'(]

Title: Why Do Thumbnails Of Edited Pictures Retain The Original Information ?
Post by: Karen W. on 26/02/2009 04:51:09

Mine asks if I want to replace the thmbnail...I click No and it saves both the old and the new pictures .
 If I say yes, it deletes the original thumbnail...and keeps the newly croped and edited piccy.

Title: Why Do Thumbnails Of Edited Pictures Retain The Original Information ?
Post by: Ultima on 26/02/2009 09:05:54

Mine does it automagically without asking [:P] But then I'm not using Windows!