March 2023 507/7EON)

cOMPUTER GRAPHICS

Tìme Alloved: 2.5 Hours Full Marks 60

Answer to Onestion No. Iof Group Ais compulsory and to be answered first. This answer is to be made in
votolonse serints) provided for the purpose. Maximum time allowed is 30 minutes, after which the loose answer
olnts will be collected and fresh answer seripts for answering the remaining part of the question will be provided, On
early submission of answer seripts of Question No. 1, astudent will get the remaining seript earlier.
Answer any Five (05) Questions from Group B.
Group A

1 Choose the correct answer from the given alternatives (any twenty): Ix20

1) The components of interactiye computer graphics are (a) A monitor (b) Display controller
(c) Frame buffer (d) all of the earlier.
i) Apixel mnask is - (a) a string containing only 0's (b) a string containing only 1's (c) a string
containing two 0's(d) a string containing both 1's and 0's.
im) DPI stands for - (a) Dots per inch, (b) Digits per inch, (c) Dots per unit, (d) Diagram per inch.
iv) RGB stands for - (a) Resolution-Global-Bright, (b) Red-Green-Blue, (c)Red-Grey-Black, (d) None
of these.
V) The Cohen-Sutherland algorithm divides the entire region into number of sub
regions. -(a) 4, (b) 8, (c) 9, (d) 10.
vi) In Mid-point circle generation algorithm, if (x,y) is the current pixel position then the x-value of
the next pixel position is - (a) x, (b) x-1, (c) x+1, (d) x+2.
vii) In scaling if Sx Sy, it means - (a) no change in object, (b) uniform scaling, (c) Shrinking object.
(d) Shape distortion.
vii) Which one of the following terms is used for the area of the computer captured by an application?
(a) Display (b) Window (c) Viewport (d) none of the earlier.
ix) Aspect Ration can be defined as - (a) The ratio of the vertical points to horizontal points
(b) collection of pixels (c) both (a) & (b) (d) none of the earlier.
X) The process of positioning an object along a straight line path from one coordinate point to another
is called - (a) Translation (b) Reflection (c) Shearing (dy Transformation.
xi) Which one of the following is the accurate and efficient line generating algorithm? (a) Midpoint
algorithm (b) DDA algorithm (c) Bresenham's line algorithm (d) None of the earlier.
Xii) Which of the following must be specified to generate a rotation? (a) Rotational distance
(b) Rotation angle (c) Co-ordinates (d) none of the earlier.
xiii) A positive value of the rotation angle (a) rotates an object in the clockwise direction (b) rotates
an object in the counter clockwise direction (c) both of the earlier (d) none of the earlier.
Xiv) Which of the following transformation is used for altering the size of the object? (a) Translation
(b) Scaling (c) Rotation (d) none of the earlier.
.According to the Cohen-Sutherland algorithm, where the line lies, if the 4-bit code of both ends is
0000 and also the logical OR gives 0000? (a) Half outside half inside (b) completely inside
(c) completely outside (d) None of the carlier.
XV) Which of the following device is used for the 3D positioning of an object? (a) Trackball (b) Mouse
() Spaceball (d) All of the earlier.
xvi) Which of the following is an example of the impact device? (a) Laser printer (b) Inkjet printer
(c) Line printer (d) None of the earlier.
xvi) Grayscale is used for -(a) Random scan display (b) Monitors with colour capability (c) Monitors
with no colour capability (d) All of the earlier.
xvii) Random scan systems are used for (a) Colour drawing application (b) Pixel drawing application
(c) Line drawing application (d) None of the carlier.
xix) How many phosphor colour dots at each pixel position in the shadow mask CRT? (a) 1(b) 7(c) 2
(d) 3.
XX) In which of the folowing CRT methods, there is an occurrence of convergence problem?
(a) Shadow mask mnethod (b) Beam penetration method (o) Both of the carlier (d) none of the
carlier.
xxi) Plasma panel is a type of- (a) Emissive display (b) Non-Emissivedisplay (c) Printer (d) None of
the carlier.,
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 Xi) Whih of the following algorithm is used to fili the interior of s
polygnt
aloorithm (b) Scan line polygon fill algorithm (c) Flo0d fill algorithm (dy (ayed ndary
Ailof the
xii)) The process of displaying 3D into a 2D display unit is called as (a) Rehetn (bi Pee
(c) Rasterization (d) Transformation.
Xx0V) If (x, V, w), w not cqual to zero, 1s a point in the homogeeous cordinate syters e
equivalentpoint in the two dimensional system 1s-(a) (%, y)Ab) (%,y, 1),(c) (zlw. yw), (6y (wx
wy).
Group B
a) Differentiate Beam Penetration method and Shadow mask method.
b) What is the resolution of an image?
What is image aspect ratio.
d) Compute the size of a 640x 480image at 240 pixels per inch.
22422
3. a) Write DDA line drawing algorithm.
b) In which situations this algorithm ís helpful?
c) What are the problems that we face at the time of implermenting thís algoríthm?
442-2
4 a Using Bresenham's line drawing algorithm, calculate the successive pixel
path between the points (20,10) and (30,18). positions along the line
b) Write full form of- PHIGS and GKS.
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5 a) Explain "Scan-Line Polygon Fill" algorithm with an example.
b Why we use Inside-Outside Tests"?
6-2
6 a) Magnify the triangle with vertices A(0, 0), B(1, 1), C(5, 2) to twíce íts size while
fixed. keeping CS. 2)
b) Prove that successive Scaling are multiplicative in nature.
6-2
7 a Why "Composite Transformatíon'" is needed?
b Derive the reflection matrix with with respect to a line
y=mx+b. 2-6
a) How transformation between coordínate systems ís
achíeved?
b) Define window and viewport in respectof viewing.
c) Find the normalization transformation that maps a window whose lower left
upper right corner is at (3, 5) onto a víewport that is entire normalized device corner
is
screen. at (1, l) and
2-2-4
a) Explain Cohen-Sutherland Line Clipping" algorithm with an example.
b) What is region code"? 6-2
10. a) Explain Sutherland-Hodgeman Polygon Clipping" algorithm with an example.
b) In which situations "Weiler-Atherton Polygon Clipping" algorithm is used? 6-2

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