Computer Graphics and Multimedia Solved Question Paper – To Score Better – RGPV (IT-601)

by

RGPV (IT-601) B.E. VI Semester

Examination, June 2015

Computer Graphics and Multimedia

l. a) What is a Computer Graphics? Explain.

Source: Click me

Use of computer to create 2D or 2D pictures.

What is the definition of computer graphics?

It is the use of computers to create and manipulate pictures on a display device. It comprises of software techniques to create, store, modify, represents pictures. It includes creation of normal pictures, graphs, lines, curves etc. on computer display which later can be easily shared with others.

What are the benefits of computer graphics?

  1. Easy capture of images and of high resolution,
  2. Easy sharing of images,
  3. Easy presentation of huge amount of information in charts and graphs,
  4. Easy presentation of flow charts.

b) Write Beam Penetration Method.   

  • Refer the following article for full answer on this.

c) Explain the working principle ofJoystick.  

  • Working principle of joystick: Explains the whole functioning of joystick how it functions, how changes in circuit happens to enable movement and various application of it that normal people will be aware about.

d) Explain the working Cathode Ray Tube?

Source: Click me

Que. Cathode ray tube (CRT) working depends on?

  1. Flow of neutrons
  2. Flow of protons
  3. Flow of electrons
  4. All of the above

Ans. 3. Flow of electrons

Cathode ray tube working depends on movement of electron beams inside vacuum chamber from one end to another, which then hits the screen and causes visible changes.

Que. What is the use of electron guns in cathode rat tube (CRT) method?

  1. To produce heat
  2. To produce electrons
  3. Both 1 & 2
  4. None of the above

Ans. 2. To produce electrons

Electron guns are used to produce focused electrons which are accelerated enough before hitting the screen. Once this accelerated electrons hits the fluorescent screen a luminous spot is generated.

What is the function of deflection plates in cathode ray tube (CRT) method?

Function of deflection plates in cathode ray tube (CRT) is to maintain voltage difference at two ends, which in turn leads to change in trajectory of electrons by deflecting them from their conventional paths.

How many deflection plates are present in cathode ray tube method?

There are two pairs of deflection plates one to deflect the ray horizontally and another to deflect it vertically.

What is the need for creating vacuum in cathode ray tube method?

To make sure that electrons move freely from one end of the tube to another.

  • Refer part-b of this question above to understand more about beam penetration method that is based on CRT.

OR

Why shadow mask used in graphics Monitors? How VGA Monitor different from SVGA Monitors?

What is the advantage of using shadow mask in graphics monitors?

Shadow mask is used in graphics monitors because of several advantages like providing very realistic images, possibility of generation of different type of colours and possibility of creation of shadow scenes.

VGA
(Video Graphics Array)		SVGA
(Super Video Graphics Array)
Provides a max resolution of upto 640 x 480 pixelsProvides a max resolution of upto 1024 x 760 pixels
Less memory intensiveMemory utilisation is high
Consists of 256 colours onlyProvides higher resolution with more colours

2 a) Give difference between DDA and Bresenham’s line algorithm.

DDA (Digital Differential Analyzer)Bresenham’s Line Algorithm
Uses Floating purpose valuesUses spherical off functions
In this algorithm rules involves multiplication as well as divisionAddition and subtraction as most performed operations
Less efficientMore efficient
CostlierCheaper
Less accurateMore accurate
Calculation is quite complexCalculation is relatively simple
No chances of optimisation is providedChances of optimisation

b) Explain B spline Curve in detail.

  • Source: Link 1 | Link 2
  • Link1 provides the difference between “Bezier curve” vs “B spline curve”
  • Link2 provides the detailed information on different types of curves i.e. properties, curves, formulas etc.
    • Implicit curves
    • Explicit curves
    • Parametric curves
    • Bezier curves and
    • B-Spline curves

c) Find the points lying on the circle centered at (5,10)having radius 8 using Bresenham’s circle Algorithm.

  • Source: Click me

3 a) Explain Composite transformation in three dimension.

Source: Click me

What happens in 3D composite transformation?

3-D Transformation is the process of manipulating the view of a three-D object with respect to its original position by modifying its physical attributes through various methods of transformation like Translation, Scaling, Rotation, Shear, etc.

What are the different types of transformations?

Different types of transformations includes translation, scaling, rotation, shearing and reflection.

  • Translation: It is the movement of an object from one place to another
  • Scaling: Is used to change the size of an object
  • Rotation: In it the object is rotated about a fixed point either in clockwise or anticlockwise direction. Amount rotated is called as angle of rotation and fixed point is called as center of rotation.

b) Explain RGB and HSV color models.

HSVRGB
Stands for hue, saturation, valueStands for red, green, blue
Cylindrical model formed by remapping the RGB coloursColour model with 3-dimensions and is depicted as cube
Hue: Specifies angle on RGB circle
– 0 degree for red
– 120 degrees for green
– 240 degrees for blue
Saturation:
– Controls the amount of colour used e.g. 100% saturation means purest colour
Value:
– Controls brightness i.e. 0% is pure black and 100% has no black present in it		—

c) Atriangle having vertex at A(0,0),B(5,5),and CO 0,4). Find the transform matrix for rotation of 45 degree about origin.

  • Source: Click me

d) Find the standard perspective projection of a point in the plane X = 25 where enter of projection at (0, 0, 0).

  • Source: Click me

OR

Why are homogeneous coordinate system used for transformation computation in computer graphics?

Reason why we use homogenous coordination in computer graphics?

Homogeneous coordinate system used for transformation computation in computer graphics because they allow common vector operations such as translation, rotation, scaling and perspective projection to be represented as a matrix by which the vector is multiplied. Also, Using homogeneous coordinates we can represent translation with a linear operator as well and thus we may shift a coordinate frame in space

4 a) Explain MIDI File Format.

  • Refer the following link: MIDI File Format
    • In the link mentioned it’s difference with normal audio files, it’s purpose, advantages and how to use it are explained in brief i.e.
      • How it stores only notes and not full audio
      • How one can use it to decode it and get the audio notes encoded in it etc.

b) Define Sampling and quantization.

  • Source: Click me
  • Follow the above link the difference between the two is very well explained.

c) Describe the architecture of a multimedia System.

d) Discuss about card, icon and page based authoring tools.

  • Source: Link 1 | Link 2
  • Refer the two links above both has very crisp and nice explanation about authoring tools their advantages and disadvantages.

OR

What is multimedia transmission protocol? Explain their role in transmission.

Source: Click me

What is the goal of multimedia transmission protocol?

The goal of multimedia transmission protocols is to make sure the secure transmission of multimedia signals between two points i.e. Point A to Point B, where the two points are connected by communication network working on specific protocols.

Function of encoding in transmission?

The function of encoding in transmission is to reduce bit rate.

What is the function of transmission protocols?

Function of transmission protocols is to make sure packetization and delivery of stream. Once stream reaches to another end it is reconstructed and decoded to finally produce a useful multimedia signal for further use e.g. Internet Protocol (IP)

What is Transport Control Protocol (TCP)?

Transport control protocol (TCP) is most used and highly reliable data transmission protocol, but is not used in real time application because of delay in retransmissions and degraded quality. Also, it does not supports multicast.

For further details on other protocols like User Datagram Protocol (UDP) and Real Time Control Protocol (RTCP) follow the above mentioned link.

5. a) What is Animation? Explain.

  • Source: Link 1 | Link 2
  • Follow the above mentioned two links animation is very well explained there.

b) What are the steps for image compression?

Source: Click me

There are three major steps in image compression transformation, quantization and encoding. (Refer the link above for detailed explanation of all the three steps)

What happens in transformation step of image compression?

In transformation images that are function of pixels i.e. x and y coordinates are transformed from spatial domain to frequency domain. It makes the computation cost cheaper because of switching to frequency domain.

What happens in quantization step of image compression?

In quantization step of image compression various levels of intensity are grouped into a particular level based pixel based mathematical function

What happens in encoding step of image compression?

In encoding step of image compression distinct characters of images are encoded in such a way that that optimal bits are consumed to represent a character. Various available encoding algorithms available are “Huffman variable-length encoding”, “Run-length encoding” etc.

c) Explain image editing plug-ins.

  • Source: Click me

d) Discuss the JPEG and MPEG File format standards.

  • Source: Click me
  • Follow the link “Joint Photographic Expert Group (JPEG)” and “Moving Picture Expert Group (MPEG)” both are explained in-depth.
  • JPEG:
    • Works on the standards for compression of digital images.
    • It’s lossy compression i.e. chances of loss of some features during compression.
  • MPEG
    • Works on the standards for compression of digital movies.
    • It has 3 main parts i.e. audio, video and system; where MPEG coordinates between audio, video and external synchronisation for playing.
Why do we compression images, what is the use of it?

Image compression saves storage by decreasing image size, hence space requirement decreases and subsequently cost for such spaces. And secondly less bandwidth is required during transfer to different devices or systems.

OR

What are different multimedia databases used for storing of images? Also explain its architecture.

  • Source: Click me
  • Images can be stored in something like
    • AWS S3,
    • HDFS,
    • a Content Delivery Network (CDN),
    • a web server,
    • file server
    • or what suits the use case

Follow the link above for architecture i.e. how JSON containing metadata information and key/value containing the main image can be used.

Refer the article “Storing and retrieving images” for understanding various nuances of image storing and retrieval.

Other relevant articles: