Multimedia

Question 1

What is multimedia?

Answer 1

Multimedia is a combination of two or more categories of information
having different transport signal characteristics
Typically, one medium is a continuous medium while another is discrete.
Image, audio, video and graphics are examples of media

Question 2

Five main elements of multimedia?

Answer 2

Multimedia combines different types of media such as text, audio, video, graphics, and animations to deliver information or entertainment content.

Question 3

What are the steps from analog to digital conversion?

Answer 3

Analog to Digital Conversion consists of three
steps to digitize an analog signal:
1. Sampling
2. Quantization
3. Binary encoding

Question 4

What is sampling?

Answer 4

Sampling is the process of capturing and digitizing analog data signals such as audio and video. The process involves measuring the amplitude of the analog signal at specific intervals of points and converting the measurements into digital data.

Question 5

What is the standard sample rate for analog?

Answer 5

It depends on the device for the telephone it is 8Khz ,for voice over 16Khz and for audio CD and mp3 44KHz and some even go to 1MHz (blu-ray disc).

Question 6

Quantization is

Answer 6

Refers to the process of reducing the precision of equality of digital data such as images audio video to make it manageable to store. It takes infinite points and turns them into finite number of points.

Question 7

Binary encoding is

Answer 7

representing info into ones and zeros.

Question 8

What is PCM?

Answer 8

Pulse Code Modulation
(PCM) a method used to
convert analog signals to
digital signals

Question 9

Nyquist’s Sampling Theorem is

Answer 9

fundamental concept in the field of signal processing and digital communication. It says that to not lose data from continuous signal from its sampled version the sampling rate should be twice or equal to the highest frequency component in the signal.

Question 10

DAC is

Answer 10

DAC- A digital-to-analog converter takes digital audio data and transforms it into an analog signal to send to
headphones or speakers.

Question 11

Sample rate is

Answer 11

Sample Rate- Measured in Hertz (Hz), this is the number of digital data samples captured every second.

Question 12

SNR is

Answer 12

SNR- Signal-to-noise ratio is the difference between the desired signal and the background system noise. In a
digital system this is linked directly to the bit-depth.

Question 13

Text data is (how is it stored)

Answer 13

is stored when typed, and then there is software that converts text into normal code. From ASCII to binary code.

Question 14

Audio data is (how is it stored)

Answer 14

we store it according to its frequency, every frequency has its code, when we compile it and turn into machine code.

Question 15

How do we know the difference between frequencies in audio data?

Answer 15

We store the analog sound waves info in digital signals then we take in the info with different voltages of 0 and 1.

Question 16

Analog signal path is

Answer 16

when the audio stays analog from input to output.

Question 17

Image sampling is

Answer 17

is the process of converting a continuous two-dimensional image into a discrete grid of pixels.

Question 18

Image quantization is

Answer 18

turns the intensity value of each pixel into a finite set of discrete values using a specific bit depth.

Question 19

Pixel (how is the word made)

Answer 19

(Pic)ture (el)ement

Question 20

Image compression

Answer 20

trying to reduce the size while keeping the quality

Question 21

What is an Image?

Answer 21

an image is a two-dimensional array or matrix of pixels (picture elements), each containing color and brightness information

Question 22

Why do we compress data?

Answer 22

To save storage;
to save time;
optimize resources;
reduce memory requirements;
improve the data access rate;
faster transfer;

Question 23

Redundancy is

Answer 23

refers to the amount of wasted space consumed by storage media to record picture info into digital image.

Question 24

What are the 3 types of image compressions?

Answer 24

Spatial redundancy: elements that are duplicated within a structure,
such as neighboring pixels in a still image. Exploiting spatial
redundancy is how compression is performed.
Spectral redundancy is due to correlation between different color
planes.
Temporal redundancy: pixels in two video frames that have the
same values in the same location. It is due to correlation between
different frames in a sequence of images such as in
videoconferencing applications in broadcast images. Exploiting
temporal redundancy is one of the primary techniques in video
compression

Question 25

What is revisable compression

Answer 25

• Reversible compression
  (loss-less compression)
  – Decoded data is the same as original
  – Applied for computer, medical data

Question 26

What is non-revisable compression

Answer 26

• Non-reversible compression
  (lossy compression)
  – Decoded data is not the same as the original
  – Compression ratio is better than reversible
  compression
  – Applied for audio and video

Question 27

Run- length

Answer 27

is a reversible compression
easy to implement
it is not fit for data in 0 n 1

Question 28

Huffman coding

Answer 28

assigns shorter words for frequent patterns

Question 29

Arithmetic coding

Answer 29

adaptively assigns words according to the statistics of objects data.

Question 30

Jpeg is

Answer 30

compressed picture or graphics

Question 31

Mpeg is

Answer 31

compressed video

Question 32

MP3 MP4 is

Answer 32

compressed audio

Question 33

Lossless methods are

Answer 33

Run-length
Huffman
Lampel Ziv

Question 34

Lossy methods are

Answer 34

JPEG MPEG MP3 MP4

Question 35

We use lossless when

Answer 35

we cant afford to lose any data, such in medical or legal data.

Question 36

We use lossy when

Answer 36

when we want to save on storage, also out eye can not notice the difference in the image or video.