Black point, white point, brightness, contrast : which formula between them ? -- RAW, Post Processing & Printing in photography-on-the.net forums

Goldmember

2,625 posts
Likes: 36
Joined Feb 2003
Location: Paris

More info

Oct 19, 2010 14:55 | #1

I'm looking for the formula that can give me the brightness and contrast values from the values of the white and black points.

I have noticed in DPP, when you change the white point or the black point in the RGB histogram, the values of RGB brightness and contrast are adjusted automatically. So I'm looking for the formula that is used there. I' have tried to search for a linear relation but it is not a linear relation...

Best DPP Threads
DPP++ Video Channel
New Version DPP++ 11.3 released

LIKES 0

chauncey

Cream of the Crop

9,696 posts
Gallery: 1 photo
Likes: 467
Joined Jun 2007
Location: MI/CO

More info

Oct 20, 2010 06:19 | #2

Your question is not very clear, what are you trying to achieve?

The things you do for yourself die with you, the things you do for others live forever.
A man's worth should be judged, not when he basks in the sun, but how he faces the storm.

My stuff...http://1x.com/member/chauncey43

LIKES 0

René Damkot

Cream of the Crop

39,856 posts
Likes: 8
Joined Feb 2005
Location: enschede, netherlands

More info

Oct 20, 2010 07:26 | #3

Looks like "brightness" moves the curve straight up and down without affecting the angle, and "contrast" changes the steepness "rotating about" the center point (what's originally 128,128).

Looks pretty linear to me...

Brightness - 100: Blacks at 0;127, whites at 255;128
Brightness + 100: Blacks at 128;0, whites at 127;255

"I think the idea of art kills creativity" - Douglas Adams
Why Color Management.
Color Problems? Click here.
MySpace
Get Colormanaged
Twitter
PERSONAL MESSAGING REGARDING SELLING OR BUYING ITEMS WITH MEMBERS WHO HAVE NO POSTS IN FORUMS AND/OR WHO YOU DO NOT KNOW FROM FORUMS IS HEREBY DECLARED STRICTLY STUPID AND YOU WILL GET BURNED.

LIKES 0

chauncey

Cream of the Crop

9,696 posts
Gallery: 1 photo
Likes: 467
Joined Jun 2007
Location: MI/CO

More info

Oct 20, 2010 08:02 as a reply to @ René Damkot's post | #4

I knew that...yeah right I did. :lol:

LIKES 0

Jump to forum... • Rules • Forums • New posts • RTAT • 'Best of' • Gallery • Gear • Reviews • Member list • Polls • Image rules • Search • Password reset • Home

Not a member yet?

Registered members may log in to forums and access all the features: full search, image upload, follow forums, own gear list and ratings, likes, more forums, private messaging, thread follow, notifications, own gallery, all settings, view hosted photos, own reviews, see more and do more... and all is free. Don't be a stranger - register now and start posting!

COOKIES DISCLAIMER: This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and to our privacy policy.
Privacy policy and cookie usage info.

THEME: Paper White | Darker
MARGINS: (this page: defaults)

Latest registered member is Mihai Bucur
1021 guests, 175 members online
Simultaneous users record so far is 15,144, that happened on Nov 22, 2018

Photography-on-the.net Digital Photography Forums is the website for photographers and all who love great photos, camera and post processing techniques, gear talk, discussion and sharing. Professionals, hobbyists, newbies and those who don't even own a camera -- all are welcome regardless of skill, favourite brand, gear, gender or age. Registering and usage is free.

	x 1600
	y 1600