What colors do people see differently. Gray or pink: Why we see colors differently. Ophthalmologists tried to explain why people see the dress differently
The photo, which divided netizens into two irreconcilable camps, was published on February 25. The girl asked her subscribers to tell how they see the dress, and suddenly it turned out that different people perceive it differently. It seems impossible: how can you mix up black and gold?
The same dress
The arguing suspected each other of deceit, cursed and even divorced. A few days later, journalists became interested in the dress, who asked the scientists what was the matter. According to the researchers, photography, due to its low quality, turned out to be an ideal model that clearly shows how the brain processes information that comes from the eyes. We automatically "subtract" the color of the background lighting from the image in order to determine how things are actually colored. Similarly, photographers adjust the white balance before shooting.
In an overexposed shot with an indistinct background, it is not clear how the room in which the dress hangs is lit. Either the room is filled with bright reddish light from incandescent lamps, or the room is in twilight, and cold halogen lamps are flickering. Those who lean (not consciously!) To the first option see the dress as white and gold, the supporters of the second version are sure that it is black and blue (if you check the colors in a graphic editor, it turns out that it is beige and blue).
The ability to perceive an image differently depending on the surrounding background is the most valuable evolutionary acquisition. Thanks to this talent, our ancestors could make the right decisions in conditions when there was clearly not enough information (for example, they noticed a spot that was suspiciously bright for a darkened cave and decided that it was a tiger). The brain adapts perception all the time - this process cannot be paused - and this is why amazing optical illusions are possible. A robot, even with a very perfect perception of colors, will never see what we see. , perhaps, will give them such an opportunity, moreover, the ability to be deceived by optical illusions can become one of the criteria to understand whether the machine is really intelligent or whether it acts according to a very complex, but initially given algorithm.
You can check that you are not a robot right now, with the help of a dozen wonderful illusions that the "Attic" has collected.
colorful dogs
This illusion is stronger in its own way than the dress illusion.
The left dog appears yellow and the right dog appears blue. In fact, they are the same, but the brain adapts the images, "removing" the main background color from them.
"Two-color" cube
Cover the junction of the two faces and the background with a sheet of paper, and it turns out that they are the same
Face A appears to be much darker than face B, but in reality they are the same color. The painted areas of shadow and bright white highlights prevent the brain from seeing the real coloring: we "by default" believe that the illuminated edge should be lighter.
Chess
Perhaps the most amazing of black and white illusions
White pieces on top, black ones on the bottom, right? Any graphics editor will tell you that they are the same.
Rectangles
Very simple and clear
The gray rectangles do not differ in color, but the brain cannot abstract from the background and perceives figures on a black background as darker, and on a white one as lighter.
artificial brightness
How to make an image brighter without increasing the brightness
When looking at vertical stripes I want to close my eyes. Moreover, when you look at them, the pupils constrict. That is, the physiological reaction that protects the eyes from excessive light occurs in response to an imaginary increase in brightness, which the brain invented itself!
Motion
It does move, doesn't it?
"Volumetric" "folds" in a two-dimensional picture move smoothly due to two features of our perception. The first is relatively simple: the eye (more precisely, the brain) automatically highlights contrasting circles so that they seem to protrude slightly from the plane of the screen. Waves appear because when we look at any image, our eyes make micro movements in all directions. At any given time, we are focused on a relatively small fragment, but thanks to micro-movements, the eyes seem to "feel" the details around the focus point, helping to perceive the whole picture. The purple circles in the illustration are framed by white and black arcs, which we unconsciously perceive as more and less illuminated areas, that is, the brain makes a flat image three-dimensional. Black and white borders are arranged in such a way that, "running" from circle to circle, our eyes "pull out" three-dimensional folds from the picture. If you focus on one place in the image, the "excitement" will stop.
vanishing spot
The most economical bleach
Slightly move away from the monitor and you will see a large stain on the sweater. Lean towards the screen or just look at it carefully, and the smudge disappears. An amazing effect was discovered back in 1804 by the Swiss physician Ignaz Troxler: he found out that if you focus on a certain part of the image, the surrounding motionless details will disappear after a few seconds. For soft and blurry details, the effect is more pronounced. In the same way, a person forgets about the ring on his finger and does not notice it, even if initially it seemed a little narrow. The illustration for this section is taken from an advertising poster for a bleach company that used the Troxler effect remarkably well.
illusory points
Count how many black dots are in the picture?
This is a very well-known illusion, and there is no clear explanation for it. Until recently, experts were sure that black dots at the intersections of gray lines appear due to some features of how retinal cells work. But now many scientists are leaning towards the idea that our brain is primarily "to blame" for the appearance of non-existent dots.
Shadow on the board
Cell A is darker than cell B, right?
Another classic illusion invented in 1995 by MIT professor Edward Adelson. It's hard to believe, but cells A and B are the same color. Adelson explains the illusion by saying that our brain interprets the image according to the context. In this case, the shaded area should be darker. According to the professor, such "self-deception" of the brain is an indicator of its strength, not weakness. For survival, it is much more important to perceive objects not in the abstract correctly, but precisely in the context of the situation.
virtual color
Look at the colored dots on Gagarin's face for a minute, and then look at the white field on the right. You will see a color image of an astronaut
An afterimage that appears before the eyes when looking at an object, especially a bright one, for a long time is called an afterimage. It occurs due to overwork of photoreceptors - light-sensitive cells in the retina. In a normal situation, due to the micromovements of the eyes, which were discussed above, different photoreceptors are excited at each moment of time. When you look at one point without looking away, the same cells are constantly working. Taking your eyes away from the object, you will see its trace for several seconds due to the fact that tired cells that have adapted to the perception of a particular image do not have time to reorganize and transmit an inadequate signal to the brain. We can say that tired photoreceptors retain the "settings" that are needed to perceive the previous picture. If the original image was colored, then additional colors will appear in the afterimage - those that, when mixed, produce gray. For example, for red, green is complementary, for yellow, purple, and for blue, orange.
They asked neurologists to explain the phenomenon of different perceptions of the color of a black and blue dress, which social media users have been discussing for the past 24 hours.
Recall that yesterday a Tumblr user under the nickname Swiked in his tumblog, a photo of a dress and asked for help determining its color. According to Swiked, she and her friends cannot agree on the same opinion: some see the dress as black and blue, others see it as white and gold. University of Washington neurologist Jay Neitz, who sees the dress in white and gold, says it's the biggest individual difference in color perception in his 35 years of practice.
The eye perceives color through reflected light waves, explains Wired. Light hits the retina of the eye, the pigments of which process the information and send it to the brain. Pigments perceive different colors depending on the wavelength of the light received. In this case, the first flash of light that hits the retina can have any wavelength (that is, a different color). After the retina receives the light reflected from the object, the brain tries to “subtract” the subsequent information from the data of the first flash.
Because people are active during the daytime, they most often perceive daylight. It can range from pinkish red to blue-white to reddish. "This will happen if the visual system sees an object and tries to ignore the chromatic shift of daylight," says Bevil Conway, a neuroscientist at Wellesley College. - So people will either ignore bluish and see a white and gold dress, or yellowish and see black and blue dress". He probably means the current lighting around the person.
Knights edition of Vice has two theories. First, differences in perception may be related to age. According to him, over time, the human retina changes and begins to perceive less of blue color. This may explain why Knights, 61, sees a white and gold dress while his student sees a black and blue one. However, this theory does not explain the differences in people of the same age.
The second assumption concerns color constancy. and colored lighting. Illumination constancy means that a person will see red in both bright and dim light. But with colored lighting, the brain makes a correction. “If I go into a room and turn on red lighting, then white objects will reflect red. And if I have some red thing with me, then it will also reflect red. By processing this information, the brain can decide that a red object is actually white, even if it saw it as red in normal light.
“I observed this with my red Volkswagen,” adds the scientist. - I got into the car when it was dark enough outside, and someone in front of me turned on the brake lights. Then my car was lit only by brake lights - and it looked white! Vice journalist tried to transfer this theory to a photo of a dress and decided that it was taken under bluish lighting. Therefore, the brain, perceiving colored lighting, thinks that the dress is actually white.
Wired asked for an in-house designer work with the photo and decompose individual sections in the RGB palette. The blue areas did turn out to be blue, but the designer attributed this to the larger area of blue in the photo. At the same time, some dark areas in the image had a palette (R 93, G 76, B 50) close to orange color. The specialist attributed this to the fact that we see this place on a white background and perceive it as black. If you cut it out and look at it on a black background, then the area R 93, G 76, B 50 may seem almost orange.
The same is said by Knights, who saw the dress in white and gold: “I printed out the picture, then cut out a piece and looked at it out of context. The color turned out to be somewhere halfway between gold and blue, but not dark blue. It's just that my brain thinks that there is blue in the light source, and the brain of other people that there is blue in the dress. Conway adds, “Most people will see blue on a white background as blue. But some may see blue on black as white."
Jay Knights ended his conversation with Vice with a promise to dedicate the rest of his life to this phenomenon. “I thought I would treat blindness, but now I will do it,” he said.
Most likely you have already seen this dress, and you probably have your own opinion about its colors. But the whole world still cannot come to an unambiguous opinion. For some, it is invariably blue and black, for others it is white and gold and nothing else!
There were even cases when at first it seemed to a person that the dress was of the same color, and then after some time he was sure of the opposite!
This dress has already done too much trouble. It's time to face the truth and find out what color it really is.
The same photo of the dress, because of which there are so many disputes:
According to some, original dress, if the lighting were better, it should look like this:
The rest believe that if it were not for the excessive light, the dress would be like this:
But why do people see different colors in the same photo? There is one version on this subject, and it has nothing to do with the monitor settings, nothing depends on them, we checked.
It's all about how the eyes of each individual person react to the illuminated object. Some decide that the dress is underlit (or that its surface is highly reflective) and their brain signals to their eyes to compensate. Hence the white and gold color. Others think that there is too much light falling on the dress (or the surface is less reflective) and their eyes show them that it is blue-black.
Everything is like in the famous Adelson optical illusion. In the picture, square "A" is the same color as square "B", although it seems that this is not the case.
In general, it turns out that the human eye sees the image as the brain perceives it. Also great importance has past experience. If a person has seen a fabric with a similar texture or a similar dress in a certain color, this will most likely affect what color they see in the photo with the dress. Little is known about this phenomenon called "difference in perception" by scientists.
Here is a photo of the actual dress. It still turned out to be blue and black.
Have you ever argued with your loved one about the color of your blouse or shirt? Have you ever been surprised to hear that a thing that you sincerely considered green is perceived by someone else as blue?
Color recognition is a delicate thing, we all have our own characteristics that affect exactly how our brain interprets visual information. There is no correct answer to the question “blue or green” in this case, since different people can perceive the same shade of color in different ways.
In order to avoid discrepancies, there is a color coding system (RGB model). From a technical point of view, each color is a mix of three tones - red, green and blue (red, green, blue), and the final shade depends on which of the tones is present in the shade in what quantity. However, the human brain sometimes interprets this mix very freely, and this is the reason for the difference in the perception of the same shade by different people.
Experiment
An experiment conducted by scientists at Optical Express showed this difference very clearly. What color do you think this square is - blue or green? Or so: this color is for you personally rather blue than green, or vice versa?
The results of the experiment showed the ambiguity of the perception of shades by different people. The researchers showed this image to non-colorblind participants (1,000 people took part in the survey) and asked them to answer the question “what color is this rectangle?”. For 32% of respondents, this color is blue, for 64% - green, and 4% could not decide. Here is how scientists themselves explain such a scatter of opinions:
Each person is unique, and many different factors can affect the perception of a color shade. The light beam enters the eyeball and reaches the retina, the light-sensitive tissue that lines the bottom of the eyeball. Next comes the process of interpretation, when the light is transformed into an electrical signal that is transmitted through the optic nerve to the cortex, the part of the brain responsible for processing the information received. How exactly the brain interprets the hue of a color can be influenced not only physiological features but also the psycho-emotional state of a person. In particular, stressed people are less sensitive to green shades, and among them there are many more of those who called the specified shade of color blue.
And yet - green or blue?
Green. From a technical point of view, the model of this color is described as RGB 0.122.116 (green tones - 122, blue - 116, red - zero). After the participants in the experiment named the color, the scientists placed two more images on both sides of the picture, a pronounced green and a pronounced blue color, after which they were again asked to answer the question “what color is this rectangle?”. Having clear color references, 97% of the participants in the experiment called the original rectangle green.
Well, if you still saw this color as blue, then think about it - maybe it's just time for you to take a vacation!
