Image-stitching and virtual tour solutions My account Updates
It is currently Fri Oct 24, 2014 12:36 pm

All times are UTC + 1 hour

Post new topic Reply to topic  [ 2 posts ] 
Author Message
 Post subject: Color correction modes 2
PostPosted: Thu Feb 23, 2006 5:26 pm 
User avatar

Joined: Mon Nov 14, 2005 4:56 pm
Posts: 5901
Location: Francin, France
Here's a full page on this sample :
Advanced color correction


 Post subject:
PostPosted: Fri Feb 24, 2006 9:06 pm 

Joined: Tue Dec 06, 2005 1:57 pm
Posts: 2946
Location: Grenoble
In this tutorial, just under the "HDR color correction" sub-title ,there is a Macromedia movie, but it don't play.

To see it I can can left click the image and select "Play" (...ou plutôt "Lire".) Another solution is to scroll down to this image quickly when the web page is opened...

About Macromedia Flash Player , my situation (XP + IE 6.0 or FireFox) is: "You have version 8,0,22,0 installed".

Alexandre wrote:
BTW : the histogram is working like photoshop level in two pass : first pass applied on each individual channel (red, green, blue) and a common final pass for every color. This isn’t well known and is in fact the cause of many misunderstanding of the level tool. It’s not a single operation on pixel, it’s a double operation on pixel.

The reason why those two pass are useful to avoid color clipping and the difference between RGB histogram and luminance histogram are explained in this short and well illustrated tutorial: (Sean T. McHugh's Cambridge in colour web-site.)

The same and not well known problem occurs when the Photoshop Curves command is used : as an example, changing the green curve while leaving the RGB curve unchanged is either impossible (a drastic change like G = 0 is impossible to recover!) or necessitates small changes to the red and blue values of most image pixels...

This suggest that using Lab mode and restricting user access to L could result in an easist interface (easiest for the user, that is) ...but I have only a keyhole view of the involved problems!


Last edited by GURL on Sun Feb 26, 2006 11:32 am, edited 1 time in total.

Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC + 1 hour

Who is online

Users browsing this forum: No registered users and 1 guest

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group