Thanks for the clear summary. There is only point that disturbs me. This argument of opponent colors doesn't make sense to me: "We can perceive purple as a combination between blue and red, but we cannot perceive a color that is a combination of blue and yellow" Well, I can see a grey color in between that as their mixture. I would not call it blueish yellow, but neither would I call purple blueish red. "Likewise there is a perception of orange as a combination of yellow and red, but there is no color perceived as greenish red." But that's just what olive in the center is. Just because we don't call it that way, it doesn't mean it is a fundamentally different color. I can perceive all those colors as combinations of two component colors. And of course orange will look more similar to yellow and red, because it's closer. Same for the first example. "The mixture gets yellow, but not greenish red." You could have made the same argument with purple to "prove" that blue and red are incompatible opponent colors. What is greenish red as opposed to yellow? Labels don't say anything about the colors itself. At best I would agree that magenta and green, red and cyan and blue and yellow are opposite pairs of colors, but so is an infinate number of combinations in between and this doesn't support opponent process theory. I'm not saying opponent theory is wrong, but the argument above doesn't support it and we should rather focus on the biological research data that we have, which appear to be unambiguous. You mentioned that another step of processing is required for creating the actual color perception. I'm wondering what that step is and if it is known or only hypothized in order the gap between opponent process theory and actual color perception.
Very good graphics explaining the opponent process. One anomaly worth rectifying is in the image at 1min into the video were R-G should be G-R. this is important as Green is the negative impulse not the red and this misinterpretation can lead to other anomalies further along the way.
Very good questions. I chose Unique Hue values from 1955 Jameson paper to honor their work. Billock (2010) has a nice graphic (color version of Jameson) that shows std theory for how color channels add together, as presented in the video. Re your question, Webster (2000) and others show nonalignment of R-G color axes (p1546), and variability of unique hues. Neitz (2008) for general comment. Would be interested to hear a comment from a color researcher.
Spectral yellow, as in the rainbow, is a pure color. Your brain processes four colors (RGB and Y), but it doesn't have a yellow cone, so it uses the combined input from red and green cones to create that sensation. Your eye, however, cannot tell the difference between the two. And stimulating all three receptors makes the sensation of white, amazing.
This proves that there is a two-way colour communication from the cones to the cortex, AND from the cortex to the cones... so do the eyes do the seeing, or does the brain do the seeing...
Brilliant video! Could you please have the "selected reference" section pasted in comment in the format of text? That could save us quite a lot of time...
wait! No, the 1:56 is totally the opposite! the cones/rods see are hit by the light, then it passes the impulse to the bipolars which in turn pass the into to the ganglions.
In the human eye the layers are thus inverted, the layers above the photoreceptors must be largely transparent and allow sufficient light to pass through to the rods and cones.
Thanks for the clear summary.
There is only point that disturbs me. This argument of opponent colors doesn't make sense to me:
"We can perceive purple as a combination between blue and red, but we cannot perceive a color that is a combination of blue and yellow"
Well, I can see a grey color in between that as their mixture. I would not call it blueish yellow, but neither would I call purple blueish red.
"Likewise there is a perception of orange as a combination of yellow and red, but there is no color perceived as greenish red."
But that's just what olive in the center is. Just because we don't call it that way, it doesn't mean it is a fundamentally different color. I can perceive all those colors as combinations of two component colors. And of course orange will look more similar to yellow and red, because it's closer. Same for the first example.
"The mixture gets yellow, but not greenish red."
You could have made the same argument with purple to "prove" that blue and red are incompatible opponent colors. What is greenish red as opposed to yellow? Labels don't say anything about the colors itself.
At best I would agree that magenta and green, red and cyan and blue and yellow are opposite pairs of colors, but so is an infinate number of combinations in between and this doesn't support opponent process theory.
I'm not saying opponent theory is wrong, but the argument above doesn't support it and we should rather focus on the biological research data that we have, which appear to be unambiguous.
You mentioned that another step of processing is required for creating the actual color perception. I'm wondering what that step is and if it is known or only hypothized in order the gap between opponent process theory and actual color perception.
I wish I found this months ago. I have been looking for books to read further on the topic. Great video. Thanks
Very good graphics explaining the opponent process. One anomaly worth rectifying is in the image at 1min into the video were R-G should be G-R. this is important as Green is the negative impulse not the red and this misinterpretation can lead to other anomalies further along the way.
Great Video! It helped me finally understand what exactly is going on! Thank you!
Thank you very much, this material is very precious.
Thank you! I find it all more logical if blue green red is changed to S M L all way through. Again thanks!
Very good questions. I chose Unique Hue values from 1955 Jameson paper to honor their work. Billock (2010) has a nice graphic (color version of Jameson) that shows std theory for how color channels add together, as presented in the video. Re your question, Webster (2000) and others show nonalignment of R-G color axes (p1546), and variability of unique hues. Neitz (2008) for general comment. Would be interested to hear a comment from a color researcher.
We need a video about visual acuity please
Great explanations! Thank you for uploading.
Very informative and yeilding video.... thanks
how is yellow a pure color (not seen as a combination of other colors) if it is a combination of green and red?
Spectral yellow, as in the rainbow, is a pure color. Your brain processes four colors (RGB and Y), but it doesn't have a yellow cone, so it uses the combined input from red and green cones to create that sensation. Your eye, however, cannot tell the difference between the two. And stimulating all three receptors makes the sensation of white, amazing.
Thank you sir! This was very helpful.
This proves that there is a two-way colour communication from the cones to the cortex, AND from the cortex to the cones... so do the eyes do the seeing, or does the brain do the seeing...
Brilliant video! Could you please have the "selected reference" section pasted in comment in the format of text? That could save us quite a lot of time...
I first learned about the color processing reading "color vision in invertebrate".
Is the slide at 9:21 mislabeled? Should R+G switch sides with Lumin?
Wonderful explanation! Thank you :)
Is was a remarkably good explanation, thank you thank you very much good sir.
I'm curious though, magenta wasn't explained in this model, why?
why does this sound like it was recording from a record player?
wait! No, the 1:56 is totally the opposite! the cones/rods see are hit by the light, then it passes the impulse to the bipolars which in turn pass the into to the ganglions.
In the human eye the layers are thus inverted, the layers above the photoreceptors must be largely transparent and allow sufficient light to pass through to the rods and cones.
Great video. Thank you.
One suggestion is to not "push" in on some of your slides. I personally find it very distracting.
I see pink after seeing green but you are saying its red
thank you so much
This is excellent!
I have opponent color phobia.
Can you see gray, in the sick people's eye's. I can. There is a dog in my home with sick gray eye dieses.
i am color advanced i have a yellow cone i can se 100,000,000 colors and normal eyes see 1,000,000