Human eye and the colorful world

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

15. THANK YOU