Title:
PREDICTIVE CODING DEVICE FOR VIDEO SIGNAL
Document Type and Number:
Japanese Patent JPH01171376
Kind Code:
A
Abstract:
PURPOSE:To widely decrease the generating degree of picture quality degradation by equipping a leak quantity controller, which sets the degree of a leak based on the output of a controller, and a variable leak device to multiply a first predictive value by a prescribed coefficient for the leak according to the instruction of this leak quantity controller and to introduce a multiplied result to a second adder. CONSTITUTION:Now, when correlatively is lowered, the absolute value of a predictive error 4 goes to be large and a switch 7 is closed to the side of a first quantizer 5. At such a time, a quantization representative value is also the large absolute value and for a value to be impressed to a second adder 17, the value from a first predictor 15 is occupational. At first, a coefficient in a variable leak device 19 is set to be small by a leak quantity controller 18 and the degree of the leak is strengthened. This is form a countermeasure against erroneous propagation at a predictive coding and decoding time. Here, the first coefficient in the variable leak device 19 is temporarily set to 0.5. After that, during a prescribed period, this condition is maintained. Here, the condition is maintained for five times operation. After that, the degree of the leak in the variable leak device is decreased by the leak quantity controller 18.
Inventors:
IDE AKIFUMI
Application Number:
JP33076187A
Publication Date:
July 06, 1989
Filing Date:
December 25, 1987
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
H04N19/182; G06T9/00; H04N19/105; H04N19/124; H04N19/136; H04N19/137; H04N19/50; H04N19/593; H04N19/65; H04N19/85; (IPC1-7): H04N7/137
Attorney, Agent or Firm:
Toshio Nakao (1 outside)