Revision as of 16:46, 11 November 2014

ECE Ph.D. Qualifying Exam in Communication Networks Signal and Image processing (CS)

Question 5, August 2013, Part 1

Part 1 , 2

@@ Line 8: / Line 8: @@
 = [[ECE-QE_CS5-2013|Question 5, August 2013]], Part 1 =
-:[[ QE637_T_Pro1 | Part 1 ]],[[ QE637_T_Pro2 | 2 ]]
+:[[ QE637 2013 Pro1 | Part 1 ]],[[ QE637 2013 Pro2 | 2 ]]
 ----
-== Solution: ==
+== Solution 1: ==
-a) <math>\gamma=1</math>
-b)
-<math>
-(x_r,y_r)=(\frac{a}{a+d+g},\frac{d}{a+d+g})
-</math> <br \>
-<math>
-(x_g,y_g)=(\frac{b}{b+e+h},\frac{e}{b+e+h})
-</math><br \>
-<math>
-(x_b,y_b)=(\frac{c}{c+f+i},\frac{f}{c+f+i})
-</math>
-c)
-<math>
-(x_w,y_w)=(\frac{a+b+c}{a+b+c+d+e+f+g+h+i},\frac{d+e+f}{a+b+c+d+e+f+g+h+i})
-</math>
-d)
-If <math> (X,Y,Z)=(0,1/2,1/2) </math>, then <math> (x,y)=(0,1/2) </math>.  [[ Image:Pro1_d.PNG ]]<br />
-In the chromaticity diagram, this point is outside the horse shoe shape, so its RGB values are not all larger than 0 (<math>R<0,G>0,B>0</math>).
-e) We are likely to see quantization artifact in dark region.
 == Solution 2: ==
-a) The gamma is 1
-b)
-<math>
-(x_r,y_r)=(\frac{a}{a+d+g},\frac{d}{a+d+g})
-</math> <br \>
-<math>
-(x_g,y_g)=(\frac{b}{b+e+h},\frac{e}{b+e+h})
-</math><br \>
-<math>
-(x_b,y_b)=(\frac{c}{c+f+i},\frac{f}{c+f+i})
-</math>
-c)
-<math>
-(x_w,y_w)=(\frac{a+b+c}{a+b+c+d+e+f+g+h+i},\frac{d+e+f}{a+b+c+d+e+f+g+h+i})
-</math>
-d) This color is imaginary. At least one of R,G,B values must be negative. Cannot be produced by this device. [[ Image:Pro1_d2.PNG ]]<br />
-<span style="color:green"> The student can be more specific about the positive or negative of each R,G,B value of this color. </span>
-e) Quantization artifacts in the dark area.
 ----
 ===Related Problem===
-Consider a color imaging device that takes input values of <math> (r,g,b) </math> and produces ouput <math> (X,Y,Z)</math> values given by
-<math>
-\left[ {\begin{array}{*{20}{c}}
-X\\
-Y\\
-Z
-\end{array}} \right] = \left[ {\begin{array}{*{20}{c}}
-a&b&c\\
-d&e&f\\
-g&h&i
-\end{array}} \right]\left[ {\begin{array}{*{20}{c}}
-r^\alpha\\
-g^\alpha\\
-b^\alpha
-\end{array}} \right]
-</math>
-a) Calculate the white point of the device in chromaticity coordinates.
-b) What are the primaries associated with the r,g, and b components respectively?
-c) What is the gamma of the device?
-d) Draw the region on the chromaticity diagram corresponding to <math> r < 0, g > 0, b > 0</math>.
 ----
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Difference between revisions of "QE637 2013 Pro1" - Rhea

Revision as of 16:46, 11 November 2014

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ECE Ph.D. Qualifying Exam in Communication Networks Signal and Image processing (CS)

Question 5, August 2013, Part 1

Solution 1:

Solution 2:

Related Problem

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