4. They have stable and precisely known internal geometries and very
low lens distortions.
The principal distance is constant, which means, that the lens
cannot be sharpened when taking photographs.
The image coordinate system is defined by (mostly) four fiducial
marks, which are mounted on the frame of the camera.
Aerial metric cameras are built into aero planes mostly looking
straight downwards.
The elements of interior orientation are known i.e the focal length
and location of the centre of the photograph.
6. The overlapping area of the two photographs (which are called a
stereo pair) can be seen in 3D, simulating man's stereoscopic vision.
In practice, a stereo pair can be produced with a single camera from
two positions or using a stereo metric camera.
A stereo metric camera in principle consists of two metric cameras
mounted at both ends of a bar, which has a precisely measured
length (mostly 40 or 120 cm).
Both cameras have the same geometric properties. Since they are
adjusted to the normal case, stereo pairs are created easily.
7. 3) AMATEUR CAMERAS
These cameras are used when the internal geometry is not stable
and unknown like normal commercially available camera.
They can only be used for purposes, where no high accuracy is
demanded.
The precision will never reach that of metric cameras.
8. SCANNERS:
Scanners allow information such as a photo or text to be input into
a computer.
Various scanners are:
1) ROTATING DRUM SCANNER
2) FLAT BED SCANNER
3) STRUCTURED LIGHT SCANNER
4) ARM AND LINE SCANNER
10. It got its name from the clear acrylic cylinder, the drum, on which the
original artwork is mounted for scanning.
They capture image information with photomultiplier
tubes (PMT), rather than the charge-coupled device (CCD) arrays.
It has the ability to control sample area and aperture size
independently. The ability to control aperture and sample size separately
is particularly useful for smoothing film grain when scanning black-and
white and color negative originals.
They are superior in resolution, color gradation, and value structure
also capable of resolutions up to 24,000 PPI. They are used when a
scanned image is going to be enlarged.
12. This type of scanner is sometimes called a reflective scanner.
They are designed for scanning prints or other flat, opaque
materials.
These scanners work by shining white light onto the object and
reading the intensity and color of the light that is reflected from it.
Some flatbed scanners have available transparency scanning
adapters but these are not suited to scanning film as a dedicated
film scanner.
14. MEASUREMENT PRINCIPLE:
A structured light scanner uses a projector and two calibrated
cameras to generate a 3D point cloud.
The projector projects a structured pattern onto the object. This
pattern is observed by the two cameras.
This generates the necessary data for the software to calculate the
3D position of every point on the lines of the pattern.
When scanning an object, the scanner will be oriented in different
positions and each scan will be aligned by the use of reference
markers or best fit algorithms.
15. RANGE AND ACCURACY:
Range: objects from the size of a coin to full cars can be measured.
Typical accuracy: depends on the size of the object, the accuracy
ranges from 10µm for very small objects (the size of a key) to 0.1
mm for larger objects (the size of a car).
ADVANTAGES:
Measurements can be done on site.
Can be used for objects of nearly any size.
17. MEASUREMENT PRINCIPLE:
It consists of 4 main segments: the base, two arm segments and the
main handle. Each of those is connected with one or more hinges, 7 in
total.
This allows the main handle to be positioned in virtually every
possible direction hence angle of every hinge is measured.
With this information the software can calculate the absolute
coordinate of the probe at the end of the main handle.
With a laser scanner attached to the arm it becomes a scanning
instrument. The arm is used to measure the position of the laser
scanner.
The laser scanner itself is then used to scan a geometric object.
18. RANGE AND ACCURACY:
Range: Both arms offer a total range of 2.4 m. Bigger objects can
be measured by using jump points for different positions.
Typical accuracy for laser scanning: 0.1-0.2 mm.
ADVANTAGES:
Portable and easy to use.
Ability to measure in tight spaces and difficult geometries.
Easy combination of single point measurements and scanned point
clouds.
21. Space Mouse is a professional 3D controller specifically
designed for manipulating objects in a 3D environment.
It permits the simultaneous control of all six degrees of
freedom (translation , rotation or combination).
Drawing time is reduced by 20%-30% increasing overall
productivity.
Going back and forth to the menu is eliminated.
Natural hand position (resting on table) eliminates fatigue.
22. 2)STEALTH 3D MOUSE
The Stealth 3D Mouse provides an two-handed 3D input for
mapping. The mouse has an optical XY motion sensor, a high-
resolution Z wheel and 10 buttons. The standard Stealth 3D Mouse
has two thumb buttons above the Z-wheel. The connection of the
Stealth 3D Mouse requires a single USB port.
23. 3)TRACKBALL
The trackball is an upside-down mouse, with the ball located on
top. A trackball has three sensors. In this the fingers are rolled
over the trackball, and internal rollers sense the motion which is
transmitted to the computer. advantage is that the trackball
remains stationary on the desk, so less room is required to use the
trackball.
24. INFRARED EMITTER:
An infrared emitter is usually an electrically-powered device that is
used to emit light wavelengths in the infrared spectrum, which are
invisible to the naked eye .
These emitters produce a red type of light invisible to the human eye
with a wavelength of around 880 nanometers.
25. OUTPUT DEVICES
Output is the result of processes that are done on the computer which can
read or another machine can read.
An output device receives information from the computer and translates
it from machine language to a form that humans understand .The various
output devices are:
1) 3D GLASSES
2) PLOTTERS
3)DISPLAY DEVICES
4)GRAPHICS CARD
26. 3D GLASSES
Types Of 3D Glasses:-
1) Anaglyph glasses
2) Pulfrich glasses
3) Polarized glasses
4) LCD Shutter glasses
28. Anaglyph 3D is the name given to the stereoscopic 3D effect
achieved by means of encoding each eye's image using filters of
different (usually chromatically opposite) colors
, typically red and blue.
The purpose of 3D glasses is to filter a separate image into each
eye.
The red image goes in the red lens and the blue image goes in the
blue lens(color separation ).
30. The Pulfrich effect is a psycho-optical phenomenon wherein lateral
motion by an object in the field of view is interpreted by the brain
as having a depth component, due to differences in processing
speed between images from the two eyes. The effect is generally
created by covering one eye with a really dark filter.
These glasses use the concept of one dark and one light lens to
form 3D images.
The image through the dark lens reaches the brain slightly after the
image that went through the clear lens, creating a 3D illusion.
32. Polarized lenses are both a gray color and unlike
anaglyph glasses allows color pass through.
The lenses are specially cut at opposing 45 degrees.
Two images are projected on the screen and each one has
a different polarization.
The polarized glasses allow only one of the images into
each eye because each lens has a different polarization.
34. LCD shutter glasses are a type of electronic 3D glasses.
They are used to view 3D images on a computer screen
First, two images are displayed on a screen, each image for
a specific eye.
The images are shown rapidly.
While the image for the left eye is shown, the right eye is
blocked by the glasses, and vice versa for the right eye.
Each lens can be turned off separately .
This happens extremely fast ( 60 flashes per second)The
lenses turn off and on so quickly that the brain just sees one
3D image that is the two images combined.
35. PLOTTERS
Plotters are used to obtain a graphic or pictorial presentation of the
final result (output).Plotters are used for variety of applications
which include drawing graphs, making maps and detailing of
houses or cars.
A plotter is a hard copy output device that reproduces graphic
images on paper using a pen that is attached to a movable arm.
These are slow devices. The graphics they produce are uniform and
of very good quality.
36. Types of plotters:
On the basis of no. of pens used:-
1)SINGLE PEN PLOTTERS
2)MULTIPLE PEN PLOTTERS
On the basis of pen interaction methods:-
1)DRUM PLOTTERS
2)FLAT BED PLOTTERS
37. 1)SINGLE PEN PLOTTER
The single pen plotter contains a single pen into penholder which
can be changed manually. The single pen plotter will consume
more time and method used by it maybe mare frustrating as
compared to multiple pen plotter.
38. 2)MULTIPLE PEN PLOTTER
The multiple pen plotter contains a main pen holder and a pen changing
assembly. The pen that is drawing is holded by the main pen holder and
rest pens lie in the assembly. The main holder collects different pens
from the pen assembly as they are needed automatically. For this, the
computer supplies instructions to the main pen holder.
39. 3)DRUM PLOTTERS
In a drum plotter the paper is placed between a drum and a platen
which holds the paper. The paper moves up and down vertically
and the pen moves left and right horizontally. Any required shaped
graph or image can be plotted on paper using these movements .
For plotting a picture image the paper moves up and down multiple
times in a drum plotter and this reduces over all accuracy of the
plotter.
The size of the graph is therefore limited only by the width of the
drum and can be of any length.
40. 4) FLAT BED PLOTTERS
Flat bed plotters are rectangle shaped open box type instruments. They
are made bigger than the largest sized paper . It contains a pen
assembly in which additional pens are arranged. The holder bar, moves
back and forth along X-axis and the pen holder moves back and forth
along Y-axis to plot an image . The paper remains fixed at its place .
They can plot any sized images, smaller as well as larger with same
accuracy. The accuracy of flat bed plotter is more than .001 inch. Thus
for higher size images the drum plotter is a better option . The pen
speed of these plotter is 15 to30 inches per second and they are slow
for complex graphical images like CAD applications.
41. 5) ELECTROSTATIC PLOTTERS
This plotter can handle large formats up to 90 cm and 120 cm in width
with effectively no limitations in length and generate map images at
moderate resolutions (300 dpi) .The colour electrostatic plotter include
competing single pass and multiple pass technologies for generating
colour hard copy on both film and paper. They are useful to generate
,edit plots , colour proofs and those maps required in small
numbers(i.e. requiring small runs )for plots. An Electrostatic Plotter
produces a raster image by charging the paper with a high voltage.
This voltage attracts toner which is then melted into the paper with
heat .This type of plotter is fast, but the quality is generally considered
to be poor when compared to pen plotters.
42. 6) INKJET PLOTTER
Inkjet plotter is a type of computer plotter that creates a digital
image by propelling droplets of ink onto paper. These printers create
image by spraying jet of ink on the paper surface and hence the name.
The speed of these printers is measured in pages per minute(PPM). It
produce very high quality printouts on any surface. It can be used to get
multicolor print outs. It provides a resolution of 300 dots per inch.
Per page printing cost of these printers is very high. They cannot be
used to take multiple carbon copies. Since it require smaller mechanical
parts, it is popular as portable printers. It provides an inexpensive way
to print full color documents.
43. 7)THERMAL PLOTTER
These plotters use a linear thermal writing head covering the whole
width of the sheet of heat sensitive paper or film.This head sweeps
across the sheet and plots out only in monochrome at reasonable
resolutions (400 dpi).Recently bi colour media have been introduced
allowing the generation of both black and red.These are used for
showing up revision detail on large scale maps.
45. Laser plotter utilizes a laser beam to produce an image and hence the
name. It is also called page printers.
Laser plotter are expensive. Speed is measured in Pages Per Minute
or PPM. It produce very high quality print and print in unlimited
variety of fonts. It cannot be used to take multiple carbon printouts.
The laser light produces the image on a drum. The laser light alters
the electrical charge on a drum whenever it hits. The drum is rolled
through a reservoir of toner, which is picked by the charged portions
of the drum. Finally the toner is transferred to the paper through a
combination of heat and pressure.
47. 1)CRT MONIT0R
The CRT monitor contains a large cathode ray tube that uses an
electron beam of varying strength to “paint” a picture onto the color
phosphorescent dots on the inside of the screen. Monitor screen
size is measured diagonally across the screen, in inches.
The resolution of the monitor is 800 x 600, or 1024 x 768, or 1600
x 1200). The spacing of the screen’s tiny phosphor dots is called
the dot pitch (dp), typically .28 or .26 (measured in millimeters). A
screen with a smaller dot pitch produces sharper images.
48. 2) FLAT PANEL MONITOR
A flat panel display usually uses an LCD (Liquid Crystal Display)
screen to display output from the computer. The LCD consists of
several thin layers that polarize the light passing through them. The
polarization of one layer, containing long thin molecules called
liquid crystals, can be controlled electronically at each pixel,
blocking varying amounts of the light to make a pixel lighter or
darker.
50. A Plasma display is composed of two parallel sheets of glass, which
enclose a mixture of discharged inert gases (like helium
, neon, argon).Groups of electrodes placed at right angles between the
panes, forming rectangular compartments, or cells, between the glass
sheets. Phosphors embedded within each cell individually emit red, green
or blue light and collectively create a single
color pixel when excited. Applied voltages to the electrodes causes them
to generate a discharge in the panel’s dielectric layer
and on its protective surface. This generates ultraviolet light that excites
the phosphors, stimulating them to emit light.
51. 3)HEAD MOUNTED DISPLAY
Head mounted display is usually a helmet like device where there
is two separate displays installed. Using two displays and some
optics it is possible to make very realistic 3D graphics. In HMD
devices we can turn our head and feel that we are inside the 3D
world.
52. 4)GRAPHICS CARD
Graphics Processor / Vendor-NVIDIA Quadro FX 1400
Video Memory Installed-128 MB
Slot type-PCI Express x16
Compatibility-PC
Technology-DDR SDRAM 256-bit
Max monitors supported-2
54. Street Mapper uses laser scanning technology to capture the
position of up to 600,000 3D point measurements per second while
in motion. The typical positional accuracy is better than 2cm and
the point-to-point accuracy within the data is 1cm.
Street Mapper offers a 360-degree field of view, a measurement
range of 300m and a scanning speed of 300kHz per
sensor, delivering high precision performance and coverage
An integrated high-resolution digital camera can be used to capture
either still or video images.
