ECE 4331, Fall, 2009. Zhu Han Department of Electrical and Computer Engineering Class 22 Nov. 6 th , 2009. Motivation – Image compression. What linear combination of 8x8 basis signals produces an 8x8 block in the image?. Learning Objectives. Introduction to the DCT and IDCT.
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Department of Electrical and Computer Engineering
Nov. 6th, 2009
What linear combination of 8x8 basis signals produces an 8x8 block in the image?
k = 0, 1, 2, …, N-1.
and i = 0, 1, 2, …, N-1.
Zonal Coding: Coefficients outside the zone mask are zeroed.
Basic idea of Motion Compensation:
Block Matching--how to find the matching block?
Table 1: MPEG-1 Constraints
The six layers of MPEG video bit stream
Available from earlier frame (X)
Available from later frame (Z)
quantizeReconstructing a reference frame that will be the same as at the decoder
I P B B B P B B B P B B B
1 5 2 3 4 9 6 7 8 13 10 11 12
A typical group of pictures in coding order
I B B B P B B B P B B B P
Spatial sampling relationship for MPEG-1
-- Luminance sample
-- Color difference sampleCoding of Macroblock
JPEG quantization table(luminance)
MPEG quantization table(for intra coding)
Non-intra coding of macroblocks
Motion vectorsA Simplified MPEG encoder