27

"Colour" is essentially a property of the distribution of wavelengths of visible light (as perceived by humans). Digital cameras only detect the amount of light at each pixel, they can't measure the wavelength and thus can't record colours directly. Colour images are produced by placing alternating red/green/blue filters in front of each pixel. By placing a ...


17

The image we can see from an infrared camera is what is known as a false color image. What this means is that a range of wavelengths in the infrared spectrum are rendered with a corresponding wavelength of visible light. Just as with visible light, a particular wavelength of infrared light can vary in intensity from just above black (shadows) to near ...


17

My monitor is calibrated (less than a month ago). I see the white/gold dress, but the highlights on the white piping have a blue tinge to me. However I have seen pics of the (supposedly) original dress, and it is a deep blue and black. To me, the only way I can reconcile this pic, and the pic of the actual dress is that if this pic was taken with a really ...


12

Our eyes and brain do things on a daily basis that make LSD's effects seem relatively tame. One of the things our brains do is a color balancing activity of their own. No one knows why for certain, but its theorized we do it so that it would be easier to track prey as they dodge in and out of shadows (prey reflect the blue sky while in the shadow, so they ...


11

Color photography is indeed based on the tri-color theory. The world saw the first color picture in 1861 made using red, green, and blue filters by James Clark Maxwell. Today’s color photography is based on his method. In 1891, Gabriel Lippmann demonstrated full color images using a single sheet of black & white film, no filters, no colored dye or ...


11

The phenomenon you describe is called color constancy, and it is enabled partially by the human vision system's chromatic adaptation and partially by something I will describe using the scientific term complicated stuff in our brains. That may sound a bit glib, but this is actually a complicated topic with whole books just scratching the surface and ...


9

The perceived color of an object depends on two elements: the intrinsic color of the object, and the color spectrum of the light shining on it. A red apple for example, will appear nearly black with a pure blue light shining on it. Depending on the difference in spectral density of different lights, the absolute perceived color of the red apple will change,...


8

Viewing these three images side by side from this article makes it fairly obvious what is going on with the viral photo: Choices about exposure and white balance determine how colors in a photo are perceived. Even black objects can be so overexposed as to over-saturate all three channels (RGB) and make black appear to be white. Amplifying the three color ...


8

To me the image appears white with a bluish tint (perhaps even a light baby blue) and the gold. or brown. It just won't read as black no matter how hard I try to convince myself. I think its the black object behind it that makes it never go there for me. I can't reconcile the deeper blue of the actual dress with the slight blue cast in the image. It reads ...


8

No. The picture straight out of your camera is what you look like to others. You don't need to reverse it. Think about it - when you take a picture of something else with your camera, you don't need to reverse it to see it how others would. (Otherwise any text in a photo would be backwards!) So it's the same when taking a picture of yourself. You might be ...


7

Is this already being done? Sure. The Hubble Space Telescope senses the near IR, visible, and near UV spectrum. Any images you see from Hubble that contain information outside of the visible spectrum are false color images. Similarly, images from Chandra, which observes the X-ray spectrum, can only be visualized by mapping its "tones" to the visible light ...


7

It's hard to tell with this low quality of image (and one which has presumably undergone some degree of post-processing), but at first glance it appears that the image is not inverted; the reflection in water is below and the real sky is above. That's because it would be quite odd for the water to be brighter than the sky — and because without prompting, one ...


7

It's more complicated than this because: Moiré appears when there is a slight difference of spatial frequency between the image and the sensor. But the cones and the rods, being organic, are not in a neatly equally spaced grid so you cannot define a spatial frequency for them (or at least there is a frequency range so the moiré is severely attenuated). Our ...


6

As a photographer, I understand both what I see (blue) and the likelihood that others don't "see" exactly what I see, for any number of reasons -- especially if you allow for different photos of the same subject taken under different lighting conditions and/or different white balance settings. If anything, I have a (completely unsubstantiated) belief that ...


6

Yes, infrared photography does record infrared wavelengths. Usually, a filter is used to make sure no visible light gets recorded. Sensors and films are not based on human eye, so their limitations are different. We can see the infrared light on resulting photographs because it is displayed in some other color(s) than infrared. In photography, colors in ...


6

The image has an obvious yellow colour cast. If i wanted to correct it, i'd put the eyedropper on the white flecks on the fabric in the lower left, which results in a blue/black dress. If we wanted to pull the blue tinge to a shade of white, we'd have to increase the yellow, and the image would look completely unnatural and clipped. So, no, there is no ...


6

Some general use photographic cameras actually record outside the visible spectrum, so there is some experience with that. Leica M8 was notoriously known for recording IR. The extended range had bad impact on color accuracy and Leica had to give customers IR/cut filters for their lenses to resolve that. Extending to UV is difficult as glass in the lenses ...


6

Have a look at this introduction to color perception and reproduction. It also contains a comparison of CIE, RGB and CMYK gamuts at the bottom, where CIE represents what the eye can do and RGB and CMYK what cameras, monitors and printers can do. In your detailed question, you basically ask, if choosing different RGB filters would accurately model human ...


6

If humans can not see it, they can not see it. But this kind of photography happens all the time using a device that is sensitive to that wavelength. For example Astrophotography or infrared photography. What it is done is that the received data is reinterpreted and re-coloured. There are not "official" colors to reinterpret the image, they can be simply ...


5

Two reasons: A camera objective (made up from many lenses) needs to focus on a plane, not an arc. And we dont see the image projected on the back of our eye ball. We build up the image from features extracted by many neurons with each their specialty. That's why we don't have to show reality to the eyes for us to see the same, we just need to construct ...


5

This is described by the Kruithof curve, and the answer depends on the brightness as well as color temperature. From Wikipedia: At the brightness of direct sunlight (along the top of the chart), anything from 4500K up will appear basically natural. At low light levels, though, much warmer (in the art sense — lower K!) light feels more natural.


5

If you'll look at the exposure data of both images you will see, that they are not equivalent. That means that the shadow spot was exposured differently and thus has different intensity. That's how auto exposure work. Generally speaking, it "thinks" that the average intensity of all pixels in a picture must be grey and so adjusts the exposure for such a ...


5

Short answer: Lenses and field of view. Long answer: Your eyes work very much like a camera, with field of view for binocular vision at about 115 degrees. According to this site, the true central focus field of view is around 40-60 degree. Now pulling out another site that I found here, you can see that for a normal AFS-C (DX format) sensor, around 20-...


5

The colors used in a Bayer filter are already centered as closely as possible to the three wavelengths of light to which human eyes are most sensitive. How sensitive each color is relative to the other two is determined by how the raw data from the sensor is processed. Changing the multipliers used for the red-filtered and blue-filtered pixels is normally ...


4

I think I found something interesting. It feels like a revelation to me! There are some articles about using the eyedropper but on CMYK model. I found a very, very simple method that I feel works well to adjust skin colors on RGB model. I am currently testing on Caucasic skins, but I feel it works for almost all skin tones. Open your color panel and use RGB ...


4

The intensities recorded by each specialized pixel can be mapped to the hue spectrum below. The Bayer matrix does not map to any color. The image is interpolated to yield a full-color-per-pixel image, where each pixel has an R, G, and B component. These RGB components can be mapped to a color space, such as sRGB or adobeRGB, but the RGB mode does not ...


4

Our eyes have a wide range of color (chromatic) adaptation.


4

I love this question. There are several concepts of resolution and several aspects that affect each one. I will be playing with different names, sorry for that, ppi, lpi, pixel density, etc, but you simply focus on the number. These variables are Distance to the viewer/physical size. Density of the display media. Interaction with the image. 3. ...


3

Let me throw a question back at you: What is the bitrate and bit depth of a vinyl record? Cameras are devices designed to, as faithfully as possible, reproduce the image that is projected onto their CCD. A human eye is an evolved device whose purpose is simply to enhance survival. It is quite complex and often behaves counter-intuitively. They have very few ...


3

Why do we 'correct' this by distorting the values according to the light source?] Because your visual system responds to relative changes in the intensities of different colors, whereas the camera sensor records absolute intensities. If you stand under a sodium streetlight for a while, you get used to that light being "white" even though it's quite a ...


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