Course Presentation

Multimedia Systems 33DD Technologies

Mahdi Amiri

May 2012 Sharif University of Technology (Two Eyes) Advantages A spare eye in case one is damaged. A wider field of view (FOV). Maximum horizontal FOV of humans: ~200º (with two eyes) One binocular FOV (seen by both eyes): ~120º Two uniocular FOV (seen by only one eye): ~40 º Binocular summation: The ability to detect faint objects is enhanced (neural summation). Perception of depth .

Page 1 Multimedia Systems, Mahdi Amiri, 3D Technologies Cyclopean Image Cyclopean image is a single mental image of a scene created by the brain by combining two images received from the two eyes.

The mythical Cyclops with a single eye

Page 2 Multimedia Systems, Mahdi Amiri, 3D Technologies Depth Perception Cues (Cont.) Accommodation of the eyeball (eyeball focus)

Focus by changing the curvature of the lens. Interposition Occlusion of one object by another

Occlusion

Page 3 Multimedia Systems, Mahdi Amiri, 3D Technologies Depth Perception Cues (Cont.) Linear perspective (convergence of parallel edges)

Parallel lines such as railway lines converge with increasing distance.

Page 4 Multimedia Systems, Mahdi Amiri, 3D Technologies Depth Perception Cues (Cont.) Familiar size and Relative size subtended visual angle of an object of known size

A retinal image of a small car is also interpreted as a distant car.

Page 5 Multimedia Systems, Mahdi Amiri, 3D Technologies Depth Perception Cues (Cont.) Aerial Perspective Vertical position (objects higher in the scene generally tend to be perceived as further away) Haze, desaturation , and a shift to bluishness

Hight Shift to bluishness Haze

Page 6 Multimedia Systems, Mahdi Amiri, 3D Technologies Depth Perception Cues (Cont.) Light and Shade

Shadow

Page 7 Multimedia Systems, Mahdi Amiri, 3D Technologies Depth Perception Cues (Cont.) Change in size of textured pattern detail.

Page 8 Multimedia Systems, Mahdi Amiri, 3D Technologies Depth Perception Cues (Cont.) Motion When an observer moves, the apparent relative motion of several stationary objects against a background gives hints about their relative distance.

This effect can be seen clearly when driving in a car. Nearby things pass quickly, while far off objects appear stationary.

Page 9 Multimedia Systems, Mahdi Amiri, 3D Technologies Depth Perception Cues:

We see a single, Cyclopean, A person’s eye are about 6565mmmm apart image from the two eyes' images. from each other. The two eyes converge on the object of attention.

The cube is shifted to the right in left The cube is shifted to the left in the eye's image. right eye's image.

The brain gives each point in the Cyclopean image a depth value, represented here by a grayscale depth map ..

Page 10 Multimedia Systems, Mahdi Amiri, 3D Technologies Depth Perception Cues, Summary Monocular Cues (involve those cues that exist for a single eye) Accommodation of the eyeball Interposition (Occlusion) Linear perspective Familiar size and Relative size Aerial Perspective Light and Shade Change in size of textured pattern Monocular Movement Parallax Binocular Cues (Cues that involve both eyes) Stereopsis

Page 11 Multimedia Systems, Mahdi Amiri, 3D Technologies 3D Technologies Types of 33DD Displays Stereoscopic Provides a different image to the viewer's left and right eyes (generally user has to use special spectacles ). Autostereoscopic Uses optical components in the display , rather than worn by the user, to enable each eye to see a different image. Computer-Generated (CGH) Create a light field identical to that which would emanate from the original scene. Volumetric displays Display points of light within a volume. Such displays use voxels instead of pixels.

Page 12 Multimedia Systems, Mahdi Amiri, 3D Technologies Definition Presenting two offset images separately to the left and right eye of the viewer. Three strategies: Have the viewer wear eyeglasses to combine separate images from two offset sources .

Have the viewer wear eyeglasses to filter offset images from a single source separated to each eye.

Have the light source split the images directionally into the viewer's eyes (no required , ).

Page 13 Multimedia Systems, Mahdi Amiri, 3D Technologies 18021802--18751875 Stereoscopy Two Offset Sources A stereoscope is composed of two pictures mounted next to each other, and a set of lenses to view the pictures through. Each picture is taken from a slightly different viewpoint that corresponds closely to the spacing of the eyes. The left picture represents what the left eye would see, and likewise for the right picture. When observing the pictures through a special viewer, the pair of two-dimensional pictures merge together into a single three-dimensional photograph. First invented by Sir Charles Wheatstone in 1838 .

Page 14 Multimedia Systems, Mahdi Amiri, 3D Technologies Stereoscopy Two Offset Sources Viewers

Conway Stereo Viewer

HeadHead--MountedMounted Display (HMD) An HMD with a separate source displayed in front of each eye to achieve a stereoscopic effect. 19201920ss--3030ss Stereo Viewer Page 15 Multimedia Systems, Mahdi Amiri, 3D Technologies Stereoscopy Filtering Single Source

Anaglyph image

Polarization of light Anaglyph ((33DD photograph) of a column head in Persepolis, Iran. Linearly polarized Circularly polarized

A linear polarizer converts an unpolarizedbeam into one with a single linear . The vertical components of all waves are transmitted, while the horizontal components are absorbed and reflected.

Page 16 Multimedia Systems, Mahdi Amiri, 3D Technologies Autostereogram Stereogram 3D craze of the 90’s

Page 17 Multimedia Systems, Mahdi Amiri, 3D Technologies www.magiceye.com Autostereogram Stereogram 3D craze of the 90’s

MultimediaPage 18 Systems, Spring 2011,Multimedia Mahdi Systems,Amiri, 3D Mahdi Technologies Amiri, 3D Technologies Autostereogram Stereogram 3D craze of the 90’s

www.magiceye.com

Page 19 Multimedia Systems, Mahdi Amiri, 3D Technologies Autostereogram Viewing Instructions The hidden image Magic Eye images may be easier to see if viewed on paper rather than a computer screen. If possible, print this image and follow the instructions below. (You don't need to print in color.) Hold the center of the printed image right up to your nose. It should be blurry. Focus as though you are looking through the image into the distance . Very slowly move the image away from your face until the two squares above the image turn into three squares. If you see four squares, move the image farther away from your face until you see three squares . If you see one or two squares, start over! When you clearly see three squares, hold the page still, and the hidden image will magically appear. Once you perceive the hidden image and depth, you can look around the entire 3D image. The longer you look, the clearer the illusion becomes. The farther away you hold the page, the deeper it becomes. Good Luck!

Page 20 Multimedia Systems, Mahdi Amiri, 3D Technologies Autostereogram Random Dot Autostereogram

The hidden image

Page 21 Multimedia Systems, Mahdi Amiri, 3D Technologies Autostereogram Random Dot Autostereogram

Page 22 Multimedia Systems, Mahdi Amiri, 3D Technologies Dr. Bela Julesz Autostereogram Stereogram was invented by Dr. Bela Julesz in 1959.

Fig. 11.. By using uniform, randomly distributed dots, Dr. Julesz eliminated the depth cues that are inherent in recognizable images.

Fig. 22.. Within the rectangle select a group of dots that make Fig. 44.. When the two up a small shape (here a circle). rectangles (Fig. 1 and Fig. 33)) are viewed together as a Fig. 33.. Create a new rectangle pair, the image of the identical to the original rectangle, circle appears to float above except that the dots within the small the background. shape have been shifted to the left. Page 23 Multimedia Systems, Mahdi Amiri, 3D Technologies Christopher Tyler Autostereogram Birth of Autostereogram In 1979, Christopher Tyler, a student of Dr. Julesz, assisted by computer programmer Maureen Clarke, discovered that the offset scheme could be applied to a single image.

The hidden image

Page 24 Multimedia Systems, Mahdi Amiri, 3D Technologies Anaglyph Image Concept

RedRed--blueblue glasses

The anaglyph method produces two slightly offset images, each individually tinted in either or . The redred--cyancyan glasses then filter the light appropriately, meaning individual eyes only see the image meant for them. The brain then merges the two slightly RedRed--cyancyan glasses different images to produce the 33DD effect. This is the main process cyan = + currently being used on 33DD BluBlu--RayRay releases and on TV broadcasts.

Page 25 Multimedia Systems, Mahdi Amiri, 3D Technologies www.decotechsoftware.com/sim/manual/pages/others/basic_concepts_of_stereo_img.html Anaglyph Image Concept How to create

Page 26 Multimedia Systems, Mahdi Amiri, 3D Technologies Anaglyph Image Example 3D Box

Page 27 Multimedia Systems, Mahdi Amiri, 3D Technologies Anaglyph Image Computer Process

Page 28 Multimedia Systems, Mahdi Amiri, 3D Technologies 3D Technologies That’s not all. To be continued…

Page 29 Multimedia Systems, Mahdi Amiri, 3D Technologies Polarization of Light Concept

The polarisedmethod is one which is becommingthe Linear Polarized 33DD Glasses method of choice when displaying 33DD images. Two images are projected at right angles to each other which are then filtered by the polarisingglasses, again meaning each individual eye only sees the image intended for it, much in the same was as the anaglyph method.

Page 30 Multimedia Systems, Mahdi Amiri, 3D Technologies Polarization of Light The Common Types of Polarizers Linear Eyeglass contain a pair of orthogonal polarizing filters Low-cost eyeglasses If viewers tilt their heads  Corrupts Circular The most widely used technology for watching 3-D films in theatres

RightRight--handed/Clockwisehanded/Clockwise circularly polarized light displayeddisplayed with and without the use of components. This would be considered LeftLeft--handed/Counterhanded/Counter--ClockwiseClockwise circularly polarized if defined from the point of view of the source.

Page 31 Multimedia Systems, Mahdi Amiri, 3D Technologies Polarization of Light Circular Polarization

RealD glasses A LeftLeft--handed/counterhanded/counter--clockwiseclockwise A rightright--handed/clockwisehanded/clockwise circularly circularly polarized wave as defined polarized wave as defined from the from the point of view of the source. point of view of the source.

Page 32 Multimedia Systems, Mahdi Amiri, 3D Technologies 3D Technologies Autostereoscopic Concept

Example of . Each eye sees different pixels of the image. Comparison of parallaxparallax--barrierbarrier and lenticular autostereoscopic displays. Note: The figure is not to scale.

Page 33 Multimedia Systems, Mahdi Amiri, 3D Technologies 3D Technologies Autostereoscopic Example devices

The Nintendo 33DSDS uses parallax barrier autostereoscopy to display a 33DD image.

Page 34 Multimedia Systems, Mahdi Amiri, 3D Technologies 3D Technologies Holography Invented in 1947 by Dennis Gabor. Holography is a technique that allows the light scattered from an object to be recorded and later reconstructed so that when an imaging system (a camera or an eye) is placed in the reconstructed beam, an image of the object will be seen even when the object is no longer present.

Dennis Gabor, 19001900--19791979

Page 35 Multimedia Systems, Mahdi Amiri, 3D Technologies Holography Concept

Holographic recording process

Holographic reconstruction process

Page 36 Multimedia Systems, Mahdi Amiri, 3D Technologies Holography ABC ABC

Workspace

Holographic recording process

Page 37 Multimedia Systems, Mahdi Amiri, 3D Technologies Holography Interference ABC

Interference

Page 38 Multimedia Systems, Mahdi Amiri, 3D Technologies Holography Diffraction Diffraction example

Diffraction

Page 39 Multimedia Systems, Mahdi Amiri, 3D Technologies Voxels

A series of voxels in a stack with a single voxelhighlighted.

Page 40 Multimedia Systems, Mahdi Amiri, 3D Technologies A pair of CrystalEyes 3D Technologies shutter glasses Liquid Crystal (LC) Shutter Glasses Pros Mostly eliminate "ghosting" which is a problem with other 3D display technologies such as RealD 3D Unlike red/cyan color filter 3D glasses, LC shutter glasses are color neutral enabling 3D viewing in the full color spectrum. Cons Flicker can be noticeable except at very high refresh rates, as each eye is effectively receiving only half of the monitor's actual refresh rate. LC shutter glasses are shutting out light half of the time ... darker picture perceived by the viewer. Expensive glasses (Over $100) Shutter glasses are also matched to the TV so it may not be possible to use your shutter glasses with a different brand 3DTV.

Page 41 Multimedia Systems, Mahdi Amiri, 3D Technologies 3D Technologies ABC Ghosting

Page 42 Multimedia Systems, Mahdi Amiri, 3D Technologies D Technologies D 33D Technologies 33D

Thank You Thank 1. http://ce.sharif.edu/~m_amiri/ 1. http://www.dml.ir/ 2. 43 Multimedia Systems Multimedia Page FIND OUT MORE AT... AT... MORE OUT FIND