Introduction to Multimedia

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Questions and Answers

What is the main reason why GIF is considered a poor format for photographic images?

GIF can only support 256 colors maximum. (correct)

GIF applies lossy compression to images.

GIF cannot support animations.

GIF files are larger than JPEG files.

How does the GIF format handle images with more than 256 colors?

It renders them without any loss of quality.

It uses a lossy compression method.

It loses nearly all color information. (correct)

It converts them into JPEG format.

Which file format is known for being the main graphics format used for photographs on the internet?

JPEG (correct)

BMP

GIF

TIFF

What is a key feature that differentiates PNG from GIF?

PNG is a lossless format. Signup and view all the answers

What type of images does JPEG format perform poorly with?

Line drawings Signup and view all the answers

Which statement highlights a significant limitation of the JPEG format?

JPEG does not support animations. Signup and view all the answers

What is a reason why GIF images became popular for advertisements?

GIF can be easily animated. Signup and view all the answers

What advantages does PNG-24 have over JPEG?

PNG-24 supports lossless compression. Signup and view all the answers

Which of the following keys is NOT considered a special purpose key on a keyboard?

F1 Signup and view all the answers

What is the primary function of a mouse?

To control the position of the cursor on the screen Signup and view all the answers

Which input device is specifically designed for use in Computer Aided Designing (CAD)?

Joystick Signup and view all the answers

What mechanism does a light pen use to function effectively?

Detecting light from the monitor screen Signup and view all the answers

How does a trackball differ from a traditional mouse?

It is a stationary device with a movable ball Signup and view all the answers

What is the purpose of a scanner?

To capture physical documents and convert them into digital form Signup and view all the answers

What type of input device is characterized by a spherical ball at both ends and allows movement in all four directions?

Joystick Signup and view all the answers

Which device is MOST likely to be used for selecting displayed menu items on a computer screen?

Light Pen Signup and view all the answers

What distinguishes emissive displays from non-emissive displays?

Emissive displays use light to create images, while non-emissive displays use existing light. Signup and view all the answers

Which type of printer typically produces quieter prints?

Laser Printer Signup and view all the answers

Which printer type is best suited for producing high-quality color prints?

Inkjet Printer Signup and view all the answers

What is a primary feature of a Dot Matrix Printer?

Creates characters using a matrix of dots Signup and view all the answers

What is a defining characteristic of Inkjet Printers?

They can produce multiple copies of printing. Signup and view all the answers

What is the primary function of a screen image projector?

To display computer information on a large screen. Signup and view all the answers

Which type of printer prints one line at a time?

Line Printer Signup and view all the answers

Which printer technology is known for being economical and widely used?

Dot Matrix Printer Signup and view all the answers

What is the process of determining the difference between current sample values and predicted values called?

Prediction error Signup and view all the answers

In predictive coding, what is typically predicted from previous samples?

The current sample value Signup and view all the answers

What is the desired characteristic of the prediction error in predictive coding?

It should be as small as possible Signup and view all the answers

Using the formula $f¯n=\frac{1}{2}(fn-1 + fn-2)$, what does $f¯n$ represent?

The mean of the last two sample values Signup and view all the answers

What type of coding exploits differences between successive sample values?

Lossless predictive coding Signup and view all the answers

What is the main advantage of predictive coding compared to traditional PCM?

Decreased storage requirements Signup and view all the answers

If $fn$ is the actual signal value, how is the prediction error $en$ calculated?

$en = fn - f¯n$ Signup and view all the answers

Which statement is true regarding the correlations in predictive coding?

Successive sample values show significant correlation. Signup and view all the answers

What does the DPCM process primarily utilize to predict the next sample?

The previous sample values Signup and view all the answers

What is the effect of using DPCM compared to PCM on the number of bits required for encoding?

DPCM reduces the number of bits required by about 25% Signup and view all the answers

In the context of DPCM, what does the prediction error represent?

The difference between the actual sample value and its predicted value Signup and view all the answers

What role does the quantizer play in the DPCM process?

It quantizes the prediction error Signup and view all the answers

Why is the predictor in DPCM based on the reconstructed, quantized signal values?

To avoid accumulation of quantization error Signup and view all the answers

What is the primary output produced by the DPCM encoder?

Quantized error values Signup and view all the answers

Which encoding technique is used for the codewords in DPCM?

Huffman coding Signup and view all the answers

What would happen if the original signal was used in the predictor instead of the quantized version?

Quantization error would tend to accumulate Signup and view all the answers

What process converts an integer base-10 number to a binary number?

Encoding Signup and view all the answers

What describes the difference between the actual sample value and the quantized value assigned to it?

Quantization Error Signup and view all the answers

What is the effect of a higher Signal to Noise Ratio (SNR) in audio quality?

Increased voice quality Signup and view all the answers

Which technique helps manage quantization error by compressing and expanding the analog signal?

Companding Signup and view all the answers

What must happen before transmitting digital audio signals over a network?

De-modulation to recover the analog signal Signup and view all the answers

Which method is standard for transmitting analog data in a digital format?

Pulse Code Modulation Signup and view all the answers

What is the primary objective of audio coding?

To achieve compact digital representations Signup and view all the answers

What describes the waveform after the quantization process?

Stepped waveform resembling the source signal Signup and view all the answers

Study Notes

Multimedia

Multimedia is an interactive medium that presents information using various methods like text, audio, video, graphics, and animations.
It facilitates powerful communication and is employed in education, training, presentations, advertising, and documentaries.

Definition of Multimedia

Multimedia is a representation of information using a combination of text, audio, video, graphics, and animations to ensure an engaging and attractive presentation.
It's a computerized way to combine different media types, such as textual data, visuals, and audio, for presenting information effectively.
Examples include email, video conferencing, instant messaging, and multimedia message service (MMS).

Components of Multimedia

Text: Used in multimedia productions to present information in various font sizes and styles.
Graphics: Enhance multimedia applications visually; two types exist:
- Bitmap images: Real-world images taken from digital cameras or scanners, non-editable, and require substantial memory.
- Vector graphics: Drawn on a computer, editable, and require less memory.
Audio: Includes speech, music, and sound effects; used for interactive teaching and multimedia presentations.
Video: Moving pictures with sound; used for conveying information in short duration, frequently used in multimedia applications for presentation of real life objects.
Animation: A technique that gives static images the appearance of movement; important for attractive presentations.

Applications of Multimedia

Business: Used for projects, team communication, and global teamwork via multimedia technology enabling team members to work globally.
Education: Educational games enhance learning for kids, allowing them to explore various capabilities in various forms like drawing, coloring, playing rhymes.
Banking: Multimedia is employed to display information about bank schemes and services to customers, assist in various transactions, training staff.
Hospitals: Multimedia aids in real-time patient monitoring, expert consultations, and diagnosis, including multimedia presentations for training for junior staff.
Pedagogy: Multimedia can aid the presentation process. Pedagogues can provide detailed and interactive challenges to students for stimulating and motivating them.

Multimedia Hardware

Processor: The brain of the computer, today Core 15 or higher processors are recommended for multimedia applications.
CPU: The central processing unit that performs data processing, stores data and instructions (program), and controls the computer's operations.
Memory and Storage Devices: Essential for storing multimedia files, original audio/video clips, project files, and backups.
- Primary Memory (RAM): Temporary storage for data and instructions currently being used by the computer, volatile.
- Flash Memory: High-speed temporary storage, act as a buffer between CPU and main memory.
- Secondary Memory (e.g., hard disk, CD, DVD): Permanent storage for multimedia files.

Input Devices

Keyboard: Inputting data to the computer, various key layouts available.
Mouse: Popular cursor-control device used to control the position of the cursor on the screen.
Joystick: A pointing device used to control cursor position; used in CAD and computer games.
Light Pen: Pen-like input device for selecting menu items or drawing on the monitor screen.
Trackball: Input device that moves the cursor by moving the ball with fingers, used in notebooks/laptops.
Scanner: Captures images from hardcopy document and transfers into digital form for editing before printing.
Digitizer: Converts analog data to digital format; used in drawing and image manipulation.
Magnetic Ink Card Reader(MICR): Primarily used in banks to read the information printed on cheques; high-speed and error-proof..
Optical Character Reader (OCR): Scans text optically and converts it into machine-readable code and stores it in memory.
Barcode Reader: Reads barcodes, transforms them into alphanumeric values, and sends them to computer.
Optical Mark Reader (OMR): Reads the marks made by a pen or pencil on sheets, commonly used in exams.

Output Devices

Monitors: Display images formed from tiny dots called pixels. Two types:
- CRT Monitors: Traditional monitor type.
- Flat Panel Displays (LCD, LED): More modern monitors with reduced volume, weights, and power requirements.
Printers: Output devices for printing documents or images.
- Dot Matrix Printers: Impact printers.
- Line Printers: Print one line at a time.
- Laser Printers: Non-impact page printers.
- Inkjet Printers: Non-impact character printers that spray ink onto paper.
Screen Image Projector: Projects information from a computer onto a large screen.
Speakers: Output devices to produce and display audio.
Digital Video Cameras: Capture images/video and store them in digital form, used for presentations.

Multimedia Software

Multimedia software tells the hardware what to do; it handles and combines different media file formats.
It includes categories like Text Editing Tools, Drawing Tools, Image Editing Tools, Sound Editing Tools, Video Editing Tools, and Multimedia Authoring Tools.

Multimedia File Formats

GIF: Graphics Interchange Format, 256 colors (suitable for simple diagrams, icons, and animations).
JPEG: Joint Photographic Experts Group, supports 24-bit color (ideal for photographic images).
PNG: Portable Network Graphics, lossless compression (supports transparency).
TIFF: Tagged Image File Format, vector graphics; high quality.
BMP: Bitmap, widely used on Windows, uncompressed; large file size.
EPS: Encapsulated Postscript, vector graphics; can be imported into nearly any application.

Digitization of Sound and Audio

Converting analogous signals to digital signals consists of Sampling(measuring amplitude at regular intervals), Quantizing(assigning discrete values to each sample), and Encoding(converting these values into binary form).
Sample Rate: Number of samples taken per second (measured in Hertz) affects the quality and file size of the audio. Higher sample rates produce greater accuracy.
Bit Depth: Number of bits used to represent each sample; greater bit depth means higher quality audio.
Pulse Code Modulation (PCM): Standard for digital audio; involves sampling, quantization, and binary encoding.
Differential Pulse Code Modulation (DPCM): Encodes the difference between successive samples, which requires fewer bits than raw PCM.
Adaptive Differential Pulse Code Modulation (ADPCM): A more sophisticated approach, where the coding parameters adapt to the characteristics of the audio.

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Description

This quiz covers the basics of multimedia, including its definition, components, and applications. Learn how text, audio, video, and graphics work together to create engaging presentations in education and advertising. Test your understanding of the various methods used in multimedia communication.