A Photography forum. PhotoBanter.com

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » PhotoBanter.com forum » Digital Photography » Digital Photography
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Does Downsampling Reduce Image Quality?



 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
  #1  
Old December 22nd 05, 09:00 AM posted to rec.photo.digital
external usenet poster
 
Posts: n/a
Default Does Downsampling Reduce Image Quality?

Ken Hall writes:

I understand that upsampling can result in a poor quality image, but I
have always been under the impression that downsampling does not
reduce the image quality.


You have to be more precise about what "image quality" means to,
particularly the size of the image when you are looking at it.

Upsampling results in *the same* quality image when viewed with the
images all the same size, or it can be better if it reduces staircasing
along edges. Downsampling reduces the image quality at the same size,
because there are fewer pixels and less fine detail.

On the other hand, if you're talking about looking at a small area of
the image at 100% scale, then the comments above make more sense.
Upsampling spreads the same information over more pixels, so the image
looks less sharp at 100%. Downsampling usually gives an image that
looks sharper at 100%, because features are smaller - but there is less
information.

The view at 100% is not what matters - it's the view of the full image
that's important.

Dave
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
8Mp Digital The Theoretical 35mm Quality Equivelant Matt Digital Photography 1144 December 17th 04 09:48 PM
Thumbnail Software? Dave Digital Photography 40 September 23rd 04 06:28 AM
Papers for the Epson 2200 - Best image quality hassy_user Digital Photography 7 September 20th 04 02:07 AM
acdsee full screen display resampling quality lacking? [email protected] Digital Photography 15 September 13th 04 11:32 PM
Dots per inch question Phil Stripling Digital Photography 13 August 19th 04 04:00 PM


All times are GMT +1. The time now is 12:01 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
Copyright 2004-2022 PhotoBanter.com.
The comments are property of their posters.