Question

Question 2 (1 point) List the factors that comprise the image formation model. Describe each briefly.

Question 3 (2 points) List three types of video signals. Compare their mutual advantages and disadvantages.

Answer 1

Question 2 :

The study of image formation encompasses the radiometric and geometric processes by which 2D images of 3D objects are formed. In the case of digital images, the image formation process also includes analog to digital conversion and sampling.

Question 3 :

There are three types of video signals as follows:

• Composite Video
• Component Video
• S-Video

Composite Video

• The first analog video color format, which uses one channel and a single cable (the audio tracks transmit in separate channels and cables). All old analog TVs and many digital TVs have composite video inputs (LG example below)

• The original TV standard combined (Y) and both color signals (U) and (V) into one channel, which uses one cable and is known as "composite video."

• Composite video was created when color was added to black & white TV in 1954. Two color signals (U and V) were multiplexed with the original monochrome signal (Y) and transmitted in the same TV channel.

• Composite Video Is Yellow

• The yellow RCA jack is the composite video socket found on video devices.

• In composite video, three source signals are combined with sync pulses to form a composite video signal. The three source signals are referred as YUV in which Y represents the brightness of the picture and it also includes the synchronizing pulses.

• The color information is carried between U and V. However, two orthogonal phases of a color carrier signal are mixed with them in the first place to form a signal called as chrominance. The Y signal and the UV signal are then combined together.

• The signals are compressed and then channeled through a single wire.

• The chrominance and luminance components can be separated at the receiver end and then the two color components can be further recovered.

• When connecting to TVs or VCRs, Composite Video uses only one wire and video color signals are mixed, not sent separately.

• The audio and sync signals are additions to this one signal. Since color and intensity are wrapped into the same signal Some interference between the luminance and chrominance signals is inevitable (unavoidable).

S-Video

• S-video was one of a number of enhancements in bringing the signal from the video cassette player to TVs, and separated video signal (luminance) and color signal (chrominance).

• S-video is a technology for transmitting video signals over a cable by dividing the video information into two separate signals: one for color (chrominance), and the other for brightness (luminance).

• When sent to a television, this produces sharper images than Composite Video, where the video information is transmitted as a single signal over one wire. This is because televisions are designed to display separate Luminance (Y) and Chrominance (C) signals.

• Computer monitors are designed for RGB (short for Red, Green, Blue monitor) signals. Most digital video devices such as digital cameras and game players produce video in RGB format. The images are clearer when displayed on a computer monitor. When displayed on a standard television, however, they look better in S-Video format than in Composite Video format.

• To use S-Video, the device sending the signals must support S-Video output and the device receiving the signals must have an S-Video input jack. Then you need an S-Video cable to connect the two devices.

• S-Video cable doesn't always come standard with a TV, and usually must be purchased separately.

• S-Video cables carry four or more wires wrapped together in an insulated sleeve, with S-Video connectors at either end. It is only for video and requires separate audio cables, but it provides a slightly better picture than a composite video cable.

• Like composite video, S-video connectors are widely used on VCRs, DVD players and receivers. The audio for both composite video and S-video uses common left/right stereo connections.

• As a result, there is less crosstalk between the color information and the crucial gray-scale information.

• S-Video cables are used for computer-to-TV output for business or home use.

Component Video

• Component video is a video signal that has been split into two or more components. In popular use, it refers to a type of analog video information that is transmitted or stored as three separate signals.

• Component analog video signals do not use R, G, and B components but rather a colorless component, termed luma, which provides brightness information (as in black-and-white video).

• This combines with one or more color-carrying components, termed chroma, that give only color information.

• In component video, the luminance (Y) and two color difference signals (U and V or I and Q) are separated into three separate analog signals that can be transmitted over three separate wires.

• Component video is used in professional video production and provides the best quality and the most accurate reproduction of colors.

• Component Video gives the best color reproduction since there is no crosstalk between the three channels. Component video requires more bandwidth and good synchronization of the three components.

• Component video cables come in three-wire sets shown below.

•