“How to recognize whether the photograph is 2 D or 3 D”
“How to recognize whether the photograph is 2 D or 3 D”
Nowadays everyone is
fascinated with ‘selfie’. Everybody’s mobile memory is full of photos. Usually most of
the information is collected from ‘Google’. After the invention of Laser, in 1960, the technique of
storage of information got vastly modified. Today we get stored information in
variety of forms. Mostly we come across 2 D and 3 D photographs. Now question
arises like “Whether the photograph is 2 D or 3 D?” Let’s discuss ---
“How to recognize whether the photograph is 2d or 3d”
Working of eye:
Fig A 
Fig B Light reflects off objects and travels in a
straight line to your eye.(Fig A) Light passes through the cornea into the
pupil and then through the lens. The cornea and lens refract the light to focus
on the retina. (Fig B) Photoreceptors on the retina convert the light into
electrical impulses. The electrical impulses pass along the optic nerve to the
brain. The brain processes the signals to create an
image.
When we look around, our eyes gather
information about the size, location, brightness, clarity and movement of the
objects around us. The optic nerve sends this visual information to
the brain.
Stereopsis is
the visual ability to see your surroundings in three dimensions (3d), allowing
a person to judge the distance between themselves and objects around them.
Depth perception allows us to see the world in three dimensions and to judge
the distance and movement between objects and ourselves. Light rays enter the pupil and
land on the retina, forming two-dimensional images. The brain processes
these images and interprets them as a three-dimensional representation of the
world around us.
2 D Photography:
2 D (two dimensional) is "flat", using the horizontal and vertical (X and Y) dimension; the image has only two dimensions and if turned to the side becomes a line. (Fig C)
Fig CFew examples of the 2 D shapes are rectangle, square, circle, triangle, or any other polygon.
Photography
is a technique to generate 2D images of 3D objects. Photography is
the art, application and practice of creating long-lasting images by recording
light radiation, either electronically by means of an image sensor or
chemically by means of a light-sensitive material such as photographic film.(
Fig D)
Fig DA photograph is a 2 D record of intensity distribution of the light scattered from a 3 D source object. In photography, the details of phase distribution are lost. Due to this different parts of an object which are at different depths appear in the same plane. Consider the photograph of a person; nose and eyes appears in the same plane, even though the phases of light waves coming from these are different. Thus the phase details which convey depth of the object are lost in the photograph.
1. In 2 D photography only intensity is
recorded therefore photography produces two dimensional picture of the object.
2. A 2 D photograph can be recorded using
normal light sources such as sunlight etc.
3. A lens is required in 2 D
photography to record the image.
4. In 2 D photography, the destruction of even
very small portion of negative or photography results in an irrecoverable loss
of information.
5. In 2 D photography, a single photo film
cannot record several images at the same time.
6. 2 D Photograph has less information
capacity.
7. Multiple images cannot be superimposed together.
8. In conventional 2 D photography, a negative pattern is produced on the film.
3 D Photography:
3 D adds
the depth (Z) dimension along with X and
Y dimensions. This third dimension
allows for rotation and visualization from multiple perspectives.
Few examples of the 3 D shapes are cube, sphere,
cone, prism, cylinder, pyramid, etc. Nowadays the monogram of company is pasted
on product package (glossy silvery sticker). This is 3 D photograph (Hologram) .
(Fig E and Fig F)
Fig E
Fig F The
traditional way of creating a 3 D image is to capture two photos from slightly
different angles to simulate the way our eyes perceive depth. If you're
shooting a stationary object, that can be done by simply moving the camera
slightly to the side in between consecutive shots.
Fig G
Fig H In
1948, Dennis Gabor (Fig G) developed a technique of recording the amplitude as
well as the phase of the light wave to get 3 D image of an object. The
technique of producing 3 D image of an object is called holography.
Holography is a technique which allows, 3 D
picture to be taken of a given object or scene. (Fig H)
The word holography is derived from two
Greek words- “holos” means “complete or whole” and “graphein” means “writing”
i.e. holography means complete writing, in other words it is 3D photography.
Holography
is a technique to generate 3 D images using interference and diffraction of
light. It uses a coherent and monochromatic source of light. A hologram is
needed to regenerate an image.
1. In holography, both intensity as well as phase of light waves
is recorded, thus holography gives 3 D picture of the object.
2. Holography requires a monochromatic, coherent light source (laser
light).
3. While recording a holography, the light from the object is
scattered directly onto the recording medium.
4. If the hologram is broken into parts, each part is capable of
reconstructing the entire object.
5. Several images can be recorded on hologram at the same time.
6. Information capacity of the hologram is very large.
7. Multiple images can be superimposed together on hologram.
8. Hologram is a positive pattern
How to recognize whether the photograph is 2 D or 3 D:
Consider the photographs of building of Dnyanshree Institute
of Engineering and Technology, Satara (Fig I Front view, Fig J Left view, Fig K Right view). Fig I represents
front view of building. Fig J represents
left view of building. Fig K represents
right view of the building. The details
of information obtained from each photograph are different. If you view one
photograph, by changing the angle of view, you won’t get any different
information. Every time you get same details from the photograph which is 2 D.
But in reality if you are observing the building, then by changing the angle of
view you will get different information from the scene which is 3 D.
From this it is concluded that in 2 D scene
the information doesn’t change even if the angle of view is changed.
2 D photography:
“When the angle of view is changed then there is no modification in the scene to be recorded that photography is 2 D”. This is because the photography records only intensity distribution of the scene. This record records only some part of information with low resolution of scene.
3 D photography:
“When the angle of view
is changed then there is modification in the scene to be recorded that
photography is 3 D”. This is because the
photography records intensity as well as phase distribution of the scene. This
record records complete information with high resolution of scene.
Thus, if you want to recognize whether the photograph is 2 D or 3 D,
then change the angle of view to see the photograph. If the information from
scene is not changed then photograph is 2 D. On the other hand if
the information from scene gets modified then the photograph is 3 D.
Courtesy: Google,
Youtube, Dnyanshree institute of Engineering and Technology, Satara.
Please observe the 3d video by 360° video recording
1.
https://youtu.be/kK_MuPEm2kQ
2.
https://youtu.be/dJNGi-bt9NM
👍👍
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