Sony RDR-GX7 - Manual (Page 26)

■ Motion Adaptive Block Noise Reduction
Block Noise Reduction is used to effectively reduce both noise
and block noise, which are characteristics of MPEG processing.
The RDR-GX7 is equipped with a Block Noise Reduction
circuit, which detects higher harmonic block noise and works
effectively in both horizontal and vertical directions in order to
minimize the appearance of block noise borders. It operates in
tandem with the Field Noise Reduction circuitry (explained
later), in a motion adaptive manner to minimize detection errors,
while automatically applying block noise reduction to video
images in which block noise is easily generated.
■ Motion Adaptive Field Noise Reduction
The most noticeable drawback of MPEG playback is video
background noise. Conventional digital noise reduction (DNR)
has the negative effects of residual images and loss of detail, so it
is not a thoroughly effective approach. The RDR-GX7, however,
employs Motion Adaptive Field Noise Reduction which
precisely detects movement and extracts the noise through
Hadamard transform, to achieve a highly efficient reduction of
noise components. In addition, there are virtually no adverse
effects to either movement or detail, making this a much more
thorough and effective approach to noise reduction than
conventional methods.
Chapter 4-4
High quality
image & sound
RDR-GX7 Technical Notes
26
Video input Video output
MC residual
movement vector
Block noise
detection
Detecting the degree
of encoding difficulty
Compensator
output
Compensation
Amplitude
Before compensation
After compensation
Block border
Block border
Block noise
Block diagram
Operation theory
The Theory of Motion Adaptive
Block Noise Compensation
Subtraction
Field one Field two Output
Noise
Video
input Video
output
Limiter
Noise detection
Motion compensation
Hadamard transform
Inverse Hadamard transform
Field memory
Movement
compensation Subtraction, Hadamard
limiter processing
Region of blocks
with movement
Blocks are analyzed and movement
vectors are calculated
is zero vector blocks only are moved, and subtraction processing is performed.
Block diagram
Operation theory
The Theory of Motion Adaptive
Field Noise Reduction
(-8 , -4)
(0 , 0)
(+7, +3)
16 pixels
4 pixels
-1 to -8 +1 to +7
Compensation pixels
Search area
Vertical search area
Horizontal search area
-1 to -4
+1 to +3
Representational Diagram of Motion
Detection by Block Matching