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Homework #3: Video Processing, DCT, and JPEG Encoding

Goal:

Assignment Date: 3/1/2010

Due Date: 3/8/2010

Related References:

• http://cs.uccs.edu/~cs525/video/video.PDF
• http://cs.uccs.edu/~cs525/dct/dct.pdf
• http://cs.uccs.edu/~cs525/dct/dctmatlab.html
• http://cs.uccs.edu/~cs525/jpeg.pdf

Description:

Part1:

1. In year 2009, ATSC decides to start developing the next generation of HDTV standards with four times the resolution of today's HDTV system. Assume one simple solution is to increase the scanning lines from 1125 to 2250 and increase the BW 4 times, other paramters (CH, AR, FR, CV, Kf) not changed. What will be the RH and Rv numbers? What will be number of equivalent pixel in one frame? See pages 12 and 13 of video.pdf for the related formula.

2. What is the main difference between a composite TV system and a component TV system? (See Page 25 of video.pdf)

3. The video standards converts RGB signal to YIQ signal format. how can we take advantage of the YIQ format, in terms of video compression utilizing the human perception system? (See Page 26 of video.pdf).

Part2:

• Blocking:  The following are the 8x8 block data for a block in a Y plane.  It has a black-white i pattern.

  
  hw3p2 =
  
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
      20    20    20    20    20    20    20    20
      20    20    20    20    20    20    20    20
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
        

• Note that the above matrix can be created with
  

  hw3p2=zeros(8,8); hw3p2([4 5],:)=20*ones(2,8)

• Question A: Apply FDCT: What is the results 8x8 DCT coefficients, expressed in matrix form?
  Note that you can run dctdemo.m for compute the dct coefficients:
  • enter the above statements to create hw3p2 matrix
  • enter getdctf(hw3p2) to display the 8x8 DCT coefficients.
  • Note that you can use format short e to see those small numbers.
• Threshold and quantization: Round the coefficients to the nearest integer numbers, given the above DCT matrix values.
• Question B: Zigzag sequence:Describe the order and content of the coefficients after arrange them in the zig-zag sequence.
• Question C: Run length and VLI Coding:Encode the intermediate sequence in (size, magnitude), (runlength, size, magnitude)+ symbol using runlength and VLI coding. Describe each data pattern of these fields in its equivalent decimal value.


• Question D: How many bits will be used to encode the intermediate sequence?
• Question E: Assume each of original source 8x8 block data is 8 bit,  the runlength and size field are 4bits without using VLC Huffman coding, magnitude fields are encoded with VLI code.  What is the compression ratio between the original data size and the encoded intermediate encoded sequence?
• Question F: If all elements of a JPEG block have the same non-zero value. How many zeros will appear in the transformed coefficients?