HCFR - Open source projector and display calibration software - Page 208 - AVS Forum | Home Theater Discussions And Reviews
Baselworld is only a few weeks away. Getting the latest news is easy, Click Here for info on how to join the Watchuseek.com newsletter list. Follow our team for updates featuring event coverage, new product unveilings, watch industry news & more!


Forum Jump: 
 386Likes
Reply
 
Thread Tools
post #6211 of 6214 Old 06-30-2015, 12:08 PM
Member
 
Slower's Avatar
 
Join Date: Mar 2010
Posts: 17
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Liked: 1
Quote:
Originally Posted by zoyd View Post
No need to send me any data, I did swap dC and dH in the calculation - thanks for the catch!
You are more than welcome, I'm glad I was able to help and thanks for the updates.

I think something went wrong with the RGB levels to HSV levels transformation. I calibrated an older Epson projector to 75% saturation. The 100% primaries and secondaries are all oversaturated and have lower than reference luminance. R and C have near-perfect hue. See the attached file. All this is in line qualitatively with the RGB levels for each of the six colours. However, switching to HSV levels gives an S value smaller than 100% for both R and M. So in HSV values they appear undersaturated!

In other files B or G appear oversaturated in RGB, but incorrectly undersaturated in HSV.
Attached Files
File Type: zip RGBvsHSV.zip (12.0 KB, 6 views)
Slower is offline  
Sponsored Links
Advertisement
 
post #6212 of 6214 Old 06-30-2015, 02:38 PM - Thread Starter
AVS Special Member
 
zoyd's Avatar
 
Join Date: Sep 2006
Location: Planet Dog
Posts: 5,749
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 901 Post(s)
Liked: 782
Quote:
Originally Posted by Slower View Post

In other files B or G appear oversaturated in RGB, but incorrectly undersaturated in HSV.
This is because the saturation error is calculated as the distance to the white point in 3 dimensions and not the distance of the projection onto the xy plane. So when you are under-luminance you will pull the saturation number down with it and why you can sometimes trade luminance for saturation (or vice-versa) in minimizing dE. If you take the example you uploaded and set the red Y such that the luminance error is close to zero the saturation bar will go positive.
zoyd is online now  
post #6213 of 6214 Old 06-30-2015, 09:54 PM
Member
 
Join Date: Mar 2015
Posts: 37
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 22 Post(s)
Liked: 1
Well, it turns out I just had my brightness set to high. This made 16 appear as a dark grey instead of black or video black. I'm still watching TV on this Toshiba 46sv709u. Experienced the artifacts that appear after adjusting color brightness, now I've solved that by increasing color while monitoring the CIE chart, thanks for the help Zoyd and the rest of you guys, now to start from scratch.
DisplayCalNoob is offline  
post #6214 of 6214 Old Today, 05:22 AM
Senior Member
 
Join Date: Dec 2014
Location: Mississauga, ON, Canada
Posts: 315
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 157 Post(s)
Liked: 22
Quote:
Originally Posted by zoyd View Post
The way it's supposed to work and let me know if it doesn't is that when you enter a black Y value via the preferences page (not directly in the grid), the 0% pattern should be skipped in both manual and automatic mode when measuring grayscale, near-black, and contrast.
zoyd,

I seem to have come across an issue with the "Override black" feature. If I turn it on and do a "Near black gray scale" run, all the points will show the manual value, i.e. I will get a flat line.

Also, it would be useful to display the Target Y in the gray scale grid, especially in situations like this when it's no longer 0. Or highlight the column to indicate it's been overridden.

Thanks.
Dominic Chan is online now  
Sponsored Links
Advertisement
 
Reply Display Calibration



Forum Jump: 

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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off