DPChallenge: A Digital Photography Contest
 

DPChallenge Forums >> Current Challenge >> jpg compression
Pages:  
Showing posts 1 - 5 of 5, (reverse)
AuthorThread
 03/15/2002 02:24:27 PM · #1
I wanted to know if anyone else has had this experience. In a recent submission I had to resize (to 640 x 480) and save my picture in jpg format. This was done in Photoshop. However, I found that even at the highest compression level my file size was twice the allowed file size (300 kb), and the image looked like hell. I almost gave up submitting the image because of the file size limit (set at 150 kb), until I decided to use ACDSee to resize. And low and behold the ACDSee resized image was well under the file size limit (136 kb), and the compressed image looked great.

If you have had this same experience & have found the explanation for the difference please post a response.
 03/15/2002 05:13:16 PM · #2
Not sure why it's doing that, you sound like you've got very odd settings for Photoshop.

If you have a fairly recent version, next time try doing "Save For Web", which gets really good quality to compression in my opinion (hence the name!).
 03/15/2002 05:30:39 PM · #3
Excellent question. I think I know what you are experiencing and I will try to explain it. When you are viewing the file size in the image size dialog box in Photoshop I don't believe it is measuring the size with the compression included. This information might be useful for a bitmap or some other lossless file. Go ahead and save your file in whatever jpeg setting you want using Photoshop, keep in mind that you will need to close the file and reopen to see if that setting looks good in the image, any moderate setting will look good. But use your explorer to navigate to the file and check it's size, that is the files exact size. I also believe that the Save to web dialog box in Photoshop will allow you to jpeg compress a file and accuratly see the resulting image and it's size.

Tim J.

* This message has been edited by the author on 3/15/2002 5:31:37 PM.
 03/15/2002 08:59:54 PM · #4
a file that results in a 300kb .jpeg at max compression would open up in photoshop to ~20MB. Must be a glitch somewhere. In PS 5.5, there's an info line at the bottom of the 'save as' dialogue box that will show you the resulting .jpeg filesize for whatever compression level you've chosen. 150kb is actually pretty generous; most places limit you to 100kb, and I've seldom had a problem at that size except with images that have been heavily sharpened and had a lot of dynamic range to begin with. Hope this helps.
 03/15/2002 11:38:45 PM · #5
I agree with the 'Save for Web' comment. Simply saving as a JPG is not enough for reducing file size and retaining crispness.
Pages:  
Current Server Time: 09/17/2026 04:35:56 PM

Please log in or register to post to the forums.
Theme: Classic / Light / Dark
Home - Challenges - Community - League - Photos - Cameras - Lenses - Learn - Help - Terms of Use - Privacy - Top ^
DPChallenge, and website content and design, Copyright © 2001-2026 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 09/17/2026 04:35:56 PM EDT.