IT-601 Computer Graphics and Multimedia - May 2024 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aExplain the Architecture of a raster scan display with a neat block diagram. How it is differ from Random scan display?
   How to answer

   • Definition and components of raster scan display: frame buffer, video controller, CRT, electron gun
   • Working: horizontal and vertical scanning, refresh, interlacing
   • Neat block diagram of raster scan system
   • Differences from random/vector scan: scanning order, resolution, applications, cost
2. 7 Marks
   bWrite in brief about various interactive input devices.
   How to answer

   • Define interactive input devices
   • List devices: keyboard, mouse, trackball, joystick, light pen, touch panel, digitizer
   • Brief function of each device
   • Role in graphical interaction
3. 7 Marks
   aDescribe with neat diagram the working of DVST. Write its advantages and disadvantages.
   How to answer

   • Principle of DVST: direct view storage tube, storage mesh
   • Working with neat diagram: electron guns, phosphor, storage grid
   • Advantages: no refresh, high resolution, low cost
   • Disadvantages: no selective erase, low contrast, no animation
4. 7 Marks
   bBriefly explain about Rubber band techniques.
   How to answer

   • Definition of rubber band technique
   • Principle of elastic line/shape stretching with cursor
   • Steps for drawing line/rectangle/circle using rubber banding
   • Use in interactive drawing and positioning
5. 7 Marks
   aFind equation of Bezier curve defined by the control points $(2, 1), (3, 2), (5, 0)$ and $(6, 2)$. Draw the curve and find its midpoints.
   How to answer

   • Cubic Bezier formula $P(t) = \sum_{i=0}^{3} B_{i,3}(t) P_i$
   • Substitute control points (2,1), (3,2), (5,0) and (6,2)
   • Derive parametric equations $x(t), y(t)$ for $0 \le t \le 1$
   • Plot curve and compute midpoint at $t=0.5$
6. 7 Marks
   bWrite down midpoint circle drawing algorithm. Draw a circle of radius 5 about origin with the help of this algorithm.
   How to answer

   • Initial decision parameter $p0 = 5/4 - r$ and update rules
   • Stepwise algorithm for 8-way symmetry
   • Iteration table for radius 5 about origin
   • Plot of circle points in all octants
7. 7 Marks
   aExplain Bresenham's line drawing algorithm with example.
   How to answer

   • Principle of Bresenham error decision parameter
   • Algorithm steps for slope |m|<1
   • Decision parameter $p_k$ update formulas
   • Worked example with pixel positions
8. 7 Marks
   bPlot a line from $(1, 1)$ to $(5, 5)$ using DDA algorithm.
   How to answer

   • DDA formulas $x_{k+1}=x_k+dx/steps$, $y_{k+1}=y_k+dy/steps$
   • Compute steps = max(|dx|,|dy|) = 4 for (1,1) to (5,5)
   • Iteration table with rounded pixels
   • Plot of line at 45 degrees
9. 7 Marks
   aRotate a Triangle $A(0, 0), B(2, 2), C(4, 2)$ about the origin and about $P(-2, -2)$ as by an angle of $45^\circ$.
   How to answer

   • Rotation matrix for $45^\circ$: $x' = x\cos\theta - y\sin\theta$
   • Rotation about origin for A(0,0), B(2,2), C(4,2)
   • Translation to P(-2,-2), rotate, translate back for second case
   • Final coordinates of rotated triangle
10. 7 Marks
    bWhat is Z Buffer technique? Write the use of depth and frame buffer.
    How to answer

    • Definition of Z-buffer / depth buffer hidden surface method
    • Algorithm: initialize depth and frame buffer, depth test per pixel
    • Use of depth buffer to store z-values
    • Use of frame buffer to store intensity/color
11. 7 Marks
    aWrite down Cohen-Sutherland line clipping algorithm with suitable example.
    How to answer

    • Region outcodes and window boundaries
    • Trivial accept/reject tests using bitwise AND/OR
    • Clipping intersection calculation steps
    • Suitable line example with before/after clipping
12. 7 Marks
    bDistinguish between parallel and perspective projection.
    How to answer

    • Definition of parallel projection: center at infinity
    • Definition of perspective projection: center at finite distance
    • Comparison on foreshortening, vanishing points, preservation
    • Applications of each type
13. 7 Marks
    aWhat do you understand by multimedia? Explain with its application.
    How to answer

    • Definition of multimedia: text, graphics, audio, video integration
    • Characteristics: interactivity, non-linearity
    • Applications: education, entertainment, medicine, web
    • Example systems
14. 7 Marks
    bDiscuss various multimedia data file formats standards.
    How to answer

    • Need for multimedia file standards
    • Image standards: JPEG, GIF, PNG, TIFF
    • Audio/video standards: MIDI, WAV, MP3, MPEG, AVI
    • Comparison of features and uses
15. 14 Marks
    Write short notes on the following: (any four)

    1. a)Reflection
    2. b)Shading
    3. c)B-spline curve
    4. d)Color models
    5. e)CRT
    6. f)Authoring tools
    How to answer

    • Select any four topics from list
    • Give definition and key points for each
    • Mention formulas/diagrams where relevant
    • Mention applications