converting RGB levels to YUV levels

kingmob · 7th October 2005, 15:44

It seems to be impossible for me to create anything logical with YV12lut to adjust levels. I cannot seem to grasp how the colors are going to change or what i need to tweak, while i do not have this problem with RGBlut.
So now i was thinking, isn't it possible to somehow convert these numbers to YUV? I'm guessing you can describe either Y, U or V by using RGB values, so each RGB combination is linked to a YUV combination. Extrapolating on this it should be possible to use this while changing levels.
If so, this would save me the colorspace conversion to RGB and back to YV12, which i now need to do on my underwatervideos.
So, am I way off with this or is it possible?

To show what i mean here is something i found by googling:

Code:

From RGB to YUV


Y = 0.299R + 0.587G + 0.114B
U = 0.492 (B-Y)
V = 0.877 (R-Y)


It can also be represented as:


Y =  0.299R + 0.587G + 0.114B
U = -0.147R - 0.289G + 0.436B
V =  0.615R - 0.515G - 0.100B




From YUV to RGB


R = Y + 1.140V
G = Y - 0.395U - 0.581V
B = Y + 2.032U

7th October 2005, 15:44	#1 \| Link
kingmob Registered User Join Date: Jun 2004 Location: Netherlands Posts: 129	converting RGB levels to YUV levels It seems to be impossible for me to create anything logical with YV12lut to adjust levels. I cannot seem to grasp how the colors are going to change or what i need to tweak, while i do not have this problem with RGBlut. So now i was thinking, isn't it possible to somehow convert these numbers to YUV? I'm guessing you can describe either Y, U or V by using RGB values, so each RGB combination is linked to a YUV combination. Extrapolating on this it should be possible to use this while changing levels. If so, this would save me the colorspace conversion to RGB and back to YV12, which i now need to do on my underwatervideos. So, am I way off with this or is it possible? To show what i mean here is something i found by googling: Code: From RGB to YUV Y = 0.299R + 0.587G + 0.114B U = 0.492 (B-Y) V = 0.877 (R-Y) It can also be represented as: Y = 0.299R + 0.587G + 0.114B U = -0.147R - 0.289G + 0.436B V = 0.615R - 0.515G - 0.100B From YUV to RGB R = Y + 1.140V G = Y - 0.395U - 0.581V B = Y + 2.032U Last edited by kingmob; 7th October 2005 at 15:46.