Code: AC15 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
· 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. For resizing the image of size
pixels
to the image of with 512 pixels, the height would be (aspect ratio is same)
(A) 1560 pixels (B) 390 pixels
(C) 673 pixels (D) none of the above
b. Which of the following is video compression algorithm?
(A) MPEG (B) NLN algorithm
(C) Phong’s method (D) Shadow mask
c. What is the location of the second pixel to be plotted with centre at origin and radius equal to 8?
(A) (0, 8) (B) (8, 0)
(C) (1, 8) (D) (8, 1)
d. In half toning, to avoid introducing unwanted artifacts into image, pattern should
(A) be symmetrical (B) not be symmetrical
(C) similar (D) not similar
e. An optimum 
dither matrix is
given by 
.
The 
dither
pattern is 
where
(A)
(B)
(C) 
(D) 
f. U is the unity matrix in Cyrus Beck algorithm a line is completely outside the region or invisible if
(A) t < 0 (B) t > 1
(C) 
(D)
All of the above
g. For second order
parametric continuity in Bezier curves with control points 
and 
where 
, we must have
(A)
(B)
(C) 
(D) 
h. For an area
representing 
pixels
the quad tree will have
(A)
levels (B)
n levels
(C) 
levels (D)
levels
i. To model decreasing speed between frames of an animation we use the function
|
(A) |
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(B) |
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(C) |
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(D) |
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j. The following KNOT vector [0, .2, .6, .9, 1.0] represents
(A) Open B-spline (B) Non uniform B-spline
(C) Periodic B-spline (D) None of the above
Answer any FIVE Questions out of EIGHT Questions.
Each question carries 16 marks.
Q.2 a. Give the first five pixel positions in the region x = 0, y = x, for a circle with centre at origin of the x – y co-ordinate system and the radius equal to 12 units. (6)
b. Using scan line seed fill algorithm fill the closed region with vertices at (10, 10), (10, 20) (35, 20) (35, 10). Give first two scan lines only. Seed is (20, 10). (6)
c. What do you mean by aliasing? Discuss one method to handle it. (4)
Q.3 a. What is the role of video controller in interactive graphic system? Explain. (7)
b. Define run length encoding and cell encoding in raster system. (4)
c. Depict pictorially the organisation of random scan system and describe it briefly. (5)
Q.4 a. Using Cyrus Beck algorithm give the co-ordinates of the clipped line with end points (0, 3) and (14, 10) in rectangular region having vertices at (6, 0) (6, 8) (12, 8) & (12, 0). (8)
b. Describe briefly the Cohen-Sutherland algorithm in 2D. (3)
c. Give the composite transformation matrix for an object which is scaled, rotated about (10, 20) and then translated. (5)
Q.5 a. Drive the transformation matrix in 3D for converting left handed system into right handed system. (4)
b. If the projector to
the plane is inclined at an angle of 
with the projection plane z = 0.
What will be the co-ordinates of the oblique projection of the point P(3, 4, 6)
onto the plane. The line joining the orthographic projection and oblique
projections makes an angle of 
with the base of plane. (9)
c. What do you mean by vanishing point? Give its application. (3)
Q.6 a. Write the characteristics of cubic B-splines. Give an example of quadratic B-spline. (6)
b. Describe briefly B-rep model of representation of solids. (6)
c. Describe the method of simulating acceleration in animation. (4)
Q.7 a. Write algorithm for traversing a BSP tree. (8)
b. Write scan line z-buffer algorithm for solving the hidden surface problem. (8)
Q.8 a. Describe the multiple sources of light illumination model of combined diffuse and specular reflections including intensity attenuation. (9)
b. Find the perspective projection of (3, 4, 5) onto the view plane Z = 3 when centre of projection is the origin. (7)
Q.9 a. What do you mean by Mandelbort set? Describe a procedure to generate the set. (6)
b. Describe briefly morphing and its applications. (6)
c. Differentiate between Gourand and Phong shading. (4)