.Light Pen-Light pen іѕ actually one more pointing input gadget. Thіѕ wіll pick up οn existence οf light. It’s a hand held pen fashioned gadget having a photocell installed іn іt’s front-еnd.
.Electrical light pen-іѕ usually combined wіth сrеаtіngcomputer software. Designed screen data files аrе usually joined using a light pen simply bу directing іt tο dіѕрlау positions. A nеw рeасе shows up οn thе screen іn thе area exactly whеrе pen іѕ placed whісh іѕ sensed through thе photocell. Thе pc software operated thе feedback transmission οf thе instrument.
.Stylus pen-іѕ actually lіkе a ballpoint pen. It’s utilized tο compose textual content οr mаkе lines (οr generate drawings аnd аlѕο pictures) οn thе exclusively developed graphics dіѕрlау οr digitizer. Pen input devices found іn several sophisticated graphic devices іѕ called Digital Pen. Generally electronic digital pen supplies much more performance compared tο stylus pen.
2..The purpose of various game controllers: gamepads, joysticksand wheels, light guns, dance pads,
.gamepads-generally feature a set of action button handled with the right thumb and a direction controller handled with the left.
.joystick and wheels-PC joysticks and wheels are going through a rough patch. There are a number of reasons for this. First of all, games that require this kind of device are not what the fashion victims want at the moment. They want First Person Shooter (FPS), action and adventure, strategy and RPG (role-playing) games - the sort of games you play with a mouse and keyboard. Here, gamepads and wheels don't really offer anything novel enough to justify new releases.
.light guns- is a pointing device for computers and a control device for arcade and video games.
.dance pads-also known as a dance mat, dance platform, or jitter deck is a flat electronic game controller used for input in dance games.
3. Explain how resolution affects the quality of a picture captured on a digital camera.
.Resolution refers to the number of pixels in an image. Resolution is sometimes identified by the width and height of the image as well as the total number of pixels in the image. For example, an image that is 2048 pixels wide and 1536 pixels high (2048X1536) contains (multiply) 3,145,728 pixels (or 3.1 Megapixels). You could call it a 2048X1536 or a 3.1 Megapixel image. As the megapixels in the pickup device in your camera increase so does the possible maximum size image you can produce. This means that a 5 megapixel camera is capable of capturing a larger image than a 3 megapixel camera.
4.Describe the uses of voice recognition, Web cams, and video conferencing
.voice recognition-enables the operating system to convert spoken words to written text. An internal driver, called an speech recognition engine, recognizes words and converts them to
text.
.web cams- a video camera which feeds its images in real time to a computer or computer network, often via USB, ethernet or Wi-Fi. Their most popular use is the establishment of video links, permitting computers to act as videophones or videoconference stations. This common use as avideo camera for the World Wide Web gave the webcam its name. Other popular uses include security surveillance and computer vision.
.video conferencing- is a set of interactive telecommunication technologies which allow two or more locations to interact via two-way video and audio transmissions simultaneously. It has also been called 'visual collaboration' and is a type of groupware.
Videoconferencing differs from videophone calls in that it's designed to serve a conference rather than individuals. It is an intermediate form of videotelephony, first deployed commercially by AT&T during the early 1970s using their Picturephone technology.
5.Discuss how various scanners and reading devices work: optical scanners,optical readers, bar code readers, RFID readers, magnetic stripe cardreaders, MICR readers, and data collection devices.
.optical scanners-A device that converts printed images and text into digital information that can be stored as a computer file and processed by graphics software.
converts printed images and text into digital information that can be edited, transmitted, and stored. Optical scanners work by electronically measuring the intensity of color at a large number of individual locations across the page (often using phototransistors), and converting these measurements into digital numerical values usable by computers and other digital devices. See also A/D converter.
.optical reader-captures visual information and translates the image into digital information the computer is capable of understanding and displaying.
An example of optical readers are marksense systems for elections where voters mark their choice by filling a rectangle, circle or oval, or by completing an arrow. After the voting a tabulating device reads the votes using "dark mark logic", whereby the computer selects the darkest mark within a given set as the correct choice or vote.
6. Summarize the various biometric devices:
. finger print reader: Fingerprint biometric is an automated digital version of the old ink-and-paper method used for more than a century for identification, primarily by law enforcement agencies (Maltoni, 2003). The biometric device requires each user to place a finger on a plate for the print to be read. Fingerprint biometrics currently has three main application areas: large-scale Automated Finger Imaging Systems (AFIS), generally used for law enforcement purposes; fraud prevention in entitlement programs; and physical and computer access. A major advantage of finger imaging is the long-time use of fingerprints and its wide acceptance by the public and law enforcement communities as a reliable means of human recognition. Others include the need for physical contact with the optical scanner, possibility of poor-quality images due to residue on the finger such as dirt and body oils (which can build up on the glass plate), as well as eroded fingerprints from scrapes, years of heavy labor or mutilation.
.Face recognition is a noninvasive process where a portion of the subject’s face is photographed and the resulting image is reduced to a digital code (Zhao, 2000). Facial recognition records the spatial geometry of distinguishing features of the face. Facial recognition technologies can encounter performance problems stemming from such factors as non-cooperative behavior of the user, lighting and other environmental variables. The main disadvantages of face recognition are similar to problems of photographs. People who look alike can fool the scanners. There are many ways in which people can significantly alter their appearance, like slight change in facial hair and style.
.Iris scanning measures the iris pattern in the colored part of the eye, although iris color has nothing to do with the biometric 6 . Iris patterns are formed randomly. As a result, the iris patterns in the left and right eyes are different, and so are the iris patterns of identical twins. Iris templates are typically around 256 bytes. Iris scanning can be used quickly for both identification and verification applications because of its large number of degrees of freedom. Disadvantages of iris recognition include problems of user acceptance, relative expense of the system as compared to other biometric technologies and the relatively memory-intensive storage requirements.
.Retinal scanning involves an electronic scan of the retina—the innermost layer of wall of the eyeball. By emitting a beam of incandescent light that bounces off the person’s retina and returns to the scanner, a retinal scanning system quickly maps the eye’s blood vessel pattern and records it into an easily retrievable digitized database 3 . The eye’s natural reflective and absorption properties are used to map a specific portion of the retinal vascular structure. The advantages of retinal scanning are its reliance on the unique characteristics of each person’s retina, as well as the fact that the retina generally remains fairly stable throughout life. Disadvantages of retinal scanning include the need for fairly close physical contact with the scanning device. Also, trauma to the eye and certain diseases can change the retinal vascular structure, and there also are concerns about public acceptance.
.Voice or speaker recognition uses vocal characteristics to identify individuals using a pass-phrase (Campbell, 1997). It involves taking the acoustic signal of a person’s voice and converting it to a unique digital code that can be stored in a template. Voice recognition systems are extremely well-suited for verifying user access over a telephone. Disadvantages of this biometric are that not only is a fairly large byte code required, but also, people’s voices can change (for example, when they are sick or in extreme emotional states). Also, phrases can be misspoken and background noises can interfere with the system.
.It is an automated method of examining an individual’s signature. This technology examines dynamics such as speed, direction and pressure of writing; the time that the stylus is in and out of contact with the “paper”; the total time taken to make the signature; and where the stylus is raised from and lowered onto the “paper”. Signature verification templates are typically 50 to 300 bytes. The key is to differentiate between the parts of the signature that are habitual and those that vary with almost every signing. Disadvantages include problems with long-term reliability, lack of accuracy and cost.
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