Physics project
- 1. The human eye and the colorful world - D Chirag
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- 3. HOW THE IMAGE IS FORMED ABOUT PIXELS WHAT PIXEL MEANS : As we know, the world is made up many – many bits of pixels or tiny little dots which come together to form an image which is formed in the brain. Since explaining the formation of the image treated as 2D is very tough, we break it down to the pixel level. In the image given here, the flower at the left is a high resolution image whereas the image at the right of it is visibly made of pixels. Both the images are made up of pixels but for us to make out the difference, we reduced the resolution of the one on the right.
- 4. FORMATION OF PIXEL IN THE EYE First rule of the pixel world is that light from one point / pixel spreads in all directions. But as you can see in the image, the other rays originating from the pixel are also entering in the eye. So where must the pixel be on the retina? As it turns out, there are only a few rays of light from the pixel that meet exactly at the retina which is identified as a pixel formed in the eye.
- 5. FORMATION OF 1D BY CONSOLIDATION OF PIXELS All the corresponding pixels seem to come together to form a image such as the 1D image show above. However, the smallest object resolution will be ~ 0.116 mm. Resolution is how well you can see two points as two distinct points. For example, if I take two pixels very close to the eye, you see it as two different points but if I move it extremely far away, you see only one single point though there are two points at a very far distance. Thus increasing resolution of any optical device lets you see those two pixels as different points
- 6. FORMATION OF 2D IMAGE BY THE PIXELS The same as we learn in mathematics, 1D forms a 2D image; we can apply the same here too. Many different lines of the formed image come together to form a 2D image. To make this a 3D image, we have two eyes which is used to recognize, how much an object has moved from image in one eye to the image in the other eye. The reason why stuff closer to a moving car moves backward faster than say, the hills at the background or the moon that almost seems to come along with us the whole time; can be used to explain how we feel the third axis in mathematics which is depth.
- 7. MAKING OUT 3D HOW IT IS DONE THE HUMAN BRAIN To make this a 3D image, we have two eyes which is used to recognize, how much an object has moved from image in one eye to the image in the other eye. The reason why stuff closer to a moving car moves backward faster than say, the hills at the background or the moon that almost seems to come along with us the whole time; can be used to explain how we feel the third axis in mathematics which is depth. In simpler words, our brain is naturally intelligent enough to subconsciously decode how nature works. Most of the seeing is done by the brain which is like a Photoshop ; desperately trying to make sense at any way possible of the visual perception it receives.
- 8. HOW WE FEEL COLOR DEFINITION OF COLOR COLOR WITHIN VISIBLE RANGE OF SPECTRUM Color is simply the intensity and wavelength of light. We can feel color just because our eyes are evolved to see color. Identifying wavelength of a light helps us to distinguish two pixels formed in the eye. A typical human eye will respond to wavelengths from about 390 to 700 nm. As mentioned earlier, there are many other rays from a given pixel which enter the eye and is still not falling on the point where we see it as a pixel. So where on retina did this ray fall on and why couldn’t we see that? The answer is simple, though the light falls elsewhere on the retina, since the greatest intensity ( illumination ) of light falling on it is not light of the one that is from the pixel we mentioned, we see some other pixel ( the one whose light intensity is high and within the visible spectrum range ) formed as a pixel there.
- 9. HOW WE SEE COLOR WHICH DO NOT BELONG TO VIBGYOR We come to see the effect of intensity while determining color here. What if there is a high intensity of blue and red. For example, the same way I explained resolution, if I have two pixels of red and blue, close to your eye, you see them as two different point and colors but at a distance where they seem to be a single point, will we still be able to differentiate red from blue. The answer is no; the brain gets confused because both red and blue is falling on the retina, so we associate another color which is pink to explain such a feeling. This is used by TV designers and manufactures to give you a more wide range of color experience. The “triluminos display” can actually emit 3 different types of color : red, blue and green. The fact that they all seem to come from one point, makes us see even other colors.
- 10. HOW WE SEE COLOR WHICH IS NOT A PART OF VIBGYOR In the Additive primary color section, we see addition of a single primary color whereas in the Subtractive primary section, we see subtraction of a single primary color. Additive colors cannot be used because they block two of the primary additive colors. Subtractive colors block only one. This is why layers of cyan, magenta and yellow are used in many color systems, including photography and printing.
- 11. IF YOU ZOOM INTO SCREEN OF YOUR TV SCREEN, THIS IS WHAT YOU WILL SEE This might be strange to know but your computer screen looks like this if you were to zoom in extremely. What makes red, green and blue special is that they constitute the primary colors. A set of colors which can be mixed to derive any color we know of.
- 12. WHAT THE 0 AND 1 FROM BINARY CODES REALLY MEAN Your computer image is also made up of individual pixels. Pixels are very small. On a monitor, there may be 72 (or 96) pixels per inch. Laser printers produce 300 or more per inch. Like a stitch in a needle point image, every pixel resides within a uniform grid, called a "bit map," that cannot be varied. The resolution of output devices is typically much higher than the 72 pixels per inch that you see on your computer monitor, so pixels are smaller. Now, let's see how color values are assigned to pixels. Color must be converted to digital code: zeros and ones. A single bit is one electrical impulse. It can be on or off. White or black.
- 13. POSSIBILITIES OF COLORS EMITTED BY A COMPUTER When two bits are used, the computer can count to four. It can identify four discrete colors or tones. Adding an additional bit raises the possible number of colors by a power of two. Many computers use 8 bits to represent color values. This means that a single pixel can represent 28 or 256 individual colors. Most digital imaging applications use 24-bit color. Three channels of 8-bit color are intermixed. Since each channel has 256 values, the total is 2563 which is 16.7 million color values.
- 14. END NOTES The Eye is the organ of sight. Eyes enable people to perform daily tasks and to learn about the world that surrounds them. Sight, or vision, is a rapidly occurring process that involves continuous interaction between the eye, the nervous system, and the brain. When someone looks at an object, what he/she is really seeing is the light that the object reflects, or gives off. This reflected light passes through the lens and falls on to the retina of the eye. Here, the light induces nerve impulses that travel through the optic nerve to the brain, where it makes an image of the object, and then that image is passed on to muscles and glands. The eye is well protected. It lies within a bony socket of the skull. The eyelids guard it in front. They blink an average of once every six seconds. This washes the eye with the salty secretion from the tear, or lachrymal, glands. Each tear gland is about the size and shape of an almond. These glands are located behind the upper eyelid at the outer corner of the eye. After passing over the eye, the liquid from the gland is drained into the nose through the tear duct at the inner corner of the
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