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8/3/2019 Fully Automated Camera System
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BY:
E.Spurthi
A.Pallavi
Ch.HarikaK.Sowmya
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Camera records and stores images which may be stillimages or moving images such as videos or movies
They may work with the light of the visible spectrum orwith other portions of electromagnetic spectrum
It has an aperture at the front for the light to enter anda recording surface at the rear to focus the light
20th century cameras used photographic film as therecording surface where as the new ones are usingimage sensors
Digital cameras have become the norm today withresolution up to 20 megapixels compared to 1 1.5 MPof the 1st digital camera.
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Captures the light from the subject and brings it toa focus on the film or detector
Design and manufacture determines the quality ofthe photograph
They come in various range of focal lengths fromextreme wide angle, wide angle, standard,medium telephoto and telephoto
Extreme wide angle for architecture due to its
capability to capture wide viewThe telephoto lens is for sports or wildlife
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Due to optical properties of photographic lenses, onlyobjects from the limited range of distances from thecamera will be produced clearly
The simplest cameras have fixed focus and use a small
aperture and wide angled lens to ensure thateverything within a range of distance from the lens is inreasonable focus
Rangefinder cameras allow the distance to objects tobe measured by means of a coupled parallax unit on
top of the camera Digital single lens reflex cameras determine the focus
visually by using objective lens and moving mirror toproject image onto ground glass
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The size of the aperture and brightness of thescene controls the amount of light that enters thecamera during a period of time
The shutter controls the length of time for which
the light hits the recording surface Large apertures with faster shutter speed and
corresponding small apertures with shutter speedslowed down give equivalent exposure
The shutters can be either mechanical orelectronic or both
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It takes the video or still photographs byrecording images via an electronic imagesensor
The image pick up device is electronic hererather than chemical as in film cameras Electronic shutter controls the exposure time
on the light sensor electronically
Both CMOS and CCD image sensors can beconstructed to give a shutter equivalentfunction
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Digital cameras use an electronic image sensorusually a CCD or a CMOS sensor to capture
CCD image sensor is an analog device. When lightstrikes the chip it is held as a small electrical
charge in each photo sensor. The charges areconverted to voltage one pixel at a time as theyare read from the chip. Additional circuitry in thecamera converts the voltage into digital
information.The CCD sensors create high-quality images as
compared to those created by CMOS sensors
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A CMOS imaging chip is a type of active pixel sensor
made using the CMOS semiconductor process. Extra
circuitry next to each photo sensor converts the light
energy to a voltage. Additional circuitry on the chipmay be included to convert the voltage to digital data.
CCD image sensors are widely used in professional,
medical, and scientific applications where high-quality
image data is required. CMOS sensors are most
commonly in cell phone cameras, web cams and in
some DSLRs
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Interline transfer CCD image sensors: Each and every pixel has a charge storage
area, which is masked, next to the light
sensitive pixel area.These form vertical column to the bottom ofthe sensor to transport the pixels down andout the bottom of the sensor.
The row of pixels from the bottom of thesensors is clocked down to a shift registerfrom where it is fed to amplifiers whichconvert charge to voltage
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It is then conditioned and digitized and fed out theback of the camera.
Interline transfer CCD interlaced:
Sensor consists of the pixel from each field
connected through the Xsg switch to a storagepixel area in the vertical CCD. From here thecollected charge is shifted to the horizontal CCDand read out line by line as a video signal. Withframe integration the charge from field 1 istransferred to the vertical CCD by Xsg1 and readout as first field. Then the charge from field 2 isread out as field 2. The result is an interlacedframe.
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Interline transfer CCD-Progressive scan: Similar to interlaced but here, from the
vertical CCD, the collected charge can beshifted to either one or two horizontal CCDregisters. Some sensors allow for twooutputs and so with two vertical shifts perline a field is available from the two video
outputs. The two outputs are then combinedin a frame grabber to a full progressiveframe image. The frame rate is double thatfrom a single output
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INTERLINE CCD INTERLACED
INTERLINE CCD PROGRESSIVE
SCAN
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They capture a full frame in a single shutter(integration) period.They differ from Interline Transfer CCDs because they
do not have a pixel storage area next to the activepixel and instead have a duplicate sensor used for
storage below the active sensor.
The image capture starts with integration period where
pixels collect electrons that are converted fromphotons. It has the advantage of 100 % fill factor and they
require half as much pixel area as frame sensors
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Each of the pixels has a photosite which is uncoveredto collect and store photons in a cavity.
Once the exposure finishes, the camera closes each ofthese, assess how many photons fell into each to
decide intensity levels. Each cavity has a filter placed over it which only allows
a particular colour of light, the common type beingbayer array which consists of alternative rows of red-green and green-blue filters.
Bayer demosaicing is the process of translating bayerarray of primary colours into a final image whichcontains full colour information at each pixel.
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Focal length is the distance between the lens and thesurface of the sensor and this length.
On increasing it, the image is magnified and theobjects appear to be closer and the reverse happens on
decreasing the focal length. Digital cameras provide both digital and optical zoom. Optical zoom lenses modify the focal length of the lens
instead of just magnifying the information that hits thesensor.
Digital zoom forms a full-size image by interpolatingthe pixels from the center of the image sensor. Thismay lead to an output of grainy or blurry images butthat depends on the resolution of the image.
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Most digital cameras have an LCD screen display,which enables to view the picture.
Previously, digital cameras used to have fixed storageinside the camera and the images were transferred by
connecting the camera to a computer. Most of today's cameras use removable storage like
memory sticks which are of removable flash memorycard format.
The images are usually stored in TIFF, which is an
uncompressed format or JPEG, which is a compressedformat and some use RAW format.
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Film Processing: No longer do you have to waste thetime and energy in developing the roll of film in a darkroom. With digital cameras, we simply can transferimage to computer using the camera's data cable.
Massive Photo Storage: Digital cameras can easilystore up to 10,000 photos, depending on the size of thememory card. This completely outweighs the storagecapacity of traditional roll film cameras.
Operating Speed: In case of earlier cameras, one
always had to wind the film after clicking a photograph.inconvenience. No such activity is required in case ofdigital cameras.
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Face Detection: High-end digital cameras have beenmeticulously designed for face detection through thecamera lens. Hence we could say goodbye to all thoseblurry faces and red-eye photographs.
Motion Detection: These days, high-end digital
cameras also come equipped with inbuilt motiondetection mechanisms which adjust moving imagesand thereby avoid blurriness. This becomes particularlyuseful when taking pictures of moving objects: a horserace or a football match in progress.
Night Modes: Clicking pictures in the dark or in dim-litsurroundings has become much easier, with nightmode features that are commonly available in today'sdigital cameras.
Continued..
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Viewing Screens: Digital cameras have viewingscreens on the camera body which allow you to viewthe image as soon as you have clicked it. If you do notlike it, you can simply delete it then and there
Waterproof: These days, there are many waterproofdigital cameras which allow you to indulge inunderwater photography.
Total VFM: Digital cameras are extremely cost-effective, adaptable, and offer total VFM (value for
money). Besides, they are constantly being upgradedwith new features, thanks to continuous technologicaladvances.
Continued..
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PIR Motion Sensors: Passiveinfrared
Detectors of warm bodied targets in motion.
Also detects bodies temperature less thanambient temperature.
Some undesired operations
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Self recording surveillance Camera Detects people moving around and starts
recording
High resolution mode of 640 X 480 pixelsfor every 3.5 or 4 seconds 1gb card stores 50,000 colour frames
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Detects obstacles
Gives signal in audio form to the owner
Avoids accidents
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IP cameras makes the detection of audio bitsimpler
Detects emergency situations and makessense of other events
Audio covers 360 degrees view coverage isextended beyond the field of view
Audio detection can trigger email, or other
alerts automatically direct camera to record.
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Thank you