Code: DC09                                                                            Subject: COMPUTER GRAPHICS

Time: 3 Hours                                                                                                     Max. Marks: 100

NOTE: There are 9 Questions in all.

· Question 1 is compulsory and carries 20 marks. Answer to Q. 1. must be written in the space provided for it in the answer book supplied and nowhere else.

· Out of the remaining EIGHT Questions answer any FIVE Questions. Each question carries 16 marks.

· Any required data not explicitly given, may be suitably assumed and stated.

Q.1       Choose the correct or best alternative in the following:                                         (2x10)

a. Coloured CRT create image of

(A)  Single colour.                              

                   (B)  Multiple colours.

(C)   Single colour with no intensity information.                                                                

(D) No colours.

b. The portion of memory used to hold pixels is called

(A) Flash memory                               (B)  Frame buffer

(C)  RAM                                           (D)  ROM

             c.   DDA algorithm used for the

(A)  Draw a rectangle                         (B) Draw a circle

(C)  Draw a polygon                            (D) Draw a line

             d.   Reflection relative to a given axis are equivalent to ____ rotation about that axis.

(A)  90º (B)  180º

(C)  60º (D)  270º

             e.   To move the image or object from one position to another.

(A) Scaling                                         (B)  Rotation

(C)  Translation                                   (D)  Skewing

             f.    Cohen-Sutherland algorithm is used for

(A) Line clipping                                 (B)  Graphical representation

(C)  3D modeling                                 (D)  None of the above

             g.   Which model is represented by tables defining edges and points?

(A) Rotation model                             (B) Translation model

(C)  Wireframe model                          (D) None of the above

             h.   When the scaling factor is S<1 then there will be

(A) Increase in size                             (B) Reduction in size

(C) Rotation                                        (D) Reflection

             i.    Hypertext allows you to have ___________ from one section to another

(A) Animation                                     (B)  Games

(C) Anchors                                        (D)  None of the above

             j.    MPEG is a

(A)  Video format                                (B)   Compression format

(C)  Text creation program                  (D)   None of the above

Answer any FIVE Questions out of EIGHT Questions.

Each question carries 16 marks.

Q.2     a.   What is the principle of polarized light?  How it is used in LCD?                          (8)

             b.   Fill the closed polygon with the vertices (5, 6), (5, 12), (14, 12), (14, 6). Use scan line seed fill algorithm with (9, 9) as seed. Fill only two scan lines.                                                                        (8)

Q.3     a.   Using Bresenham’s algorithm draw a circle whose centre is (0, 0) and radius is 8 units.                   (10)

             b.   How computer graphics is useful for simulation, animation and video games?                       (6)

Q.4     a.   Write the advantage and disadvantage of DDA line algorithm.  How it can be rectified?                   (4)

b.   Scale the triangle with vertices A(0, 0), B(1, 1) and C(5, 2) three time its size while keeping C(5, 2) fixed.                                                             (8)

c.   Prove that 2D rotations are commutative.                                                           (4)

Q.5     a.   Describe Floating horizon algorithm. What are the advantages & disadvantages of Floating horizon algorithm.                                                           (8)

     b.   Explain B-spline curve and write the pseudocode for drawing the B-spline curve.  What are the condition for smoothly joining curve segments.          (8)

  Q.6     a. Describe Midpoint subdivision clipping algorithm.                                               (8)

             b.   Explain generation of bar charts and pie charts.                                                   (8)

Q.7     a.   Using the origin as the centre of projection, derive the perspective transformation onto the plane passing through the point  and having the normal vector .     (8)

b.   Explain Z-buffer algorithm.  What are advantages & disadvantages of       Z-buffer algorithm?                                                                    (8)

Q.8     a.   What are the various hardware components required for multimedia applications?  Explain.             (8)

             b.   What are the advantages of MIDI over digital audio?                                          (4)

             c.   Explain any multimedia software.                                                                        (4)

Q.9           Write short notes on the following:

(i) Octrees.            

(ii) Diffuse Reflection.

(iii) Image Scanners.

(iv) Optical Mouse.                                                                                     (44)