Image signal coding system

• US 6,307,973 B2
• Filed: 12/04/2000
• Issued: 10/23/2001
• Est. Priority Date: 10/22/1991
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Yamada, Yoshihisa, Nishikawa, Hirofumi, Asai, Kohtaro, Murakami, Tokumichi
• Primary Examiner(s): Couso, Jose L.
• Application Number:
  US09/728,076
• Publication Number:
  US 20010000072A1
• Time in Patent Office: 323 Days
• Field of Search: 382/232, 382/233, 382/236, 382/238, 382/240, 382/248, 382/250, 348/384, 348/394, 348/395, 348/400, 348/401-404, 348/407-416, 348/420, 348/421, 348/425, 348/430, 348/431, 348/699, 358/432, 358/433
• US Class Current: 382/238
• CPC Class Codes: H04N 19/105 Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
• CPC Class Codes: H04N 19/112 according to a given display mode, e.g. for interlaced or progressive display mode
• CPC Class Codes: H04N 19/119 Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/152 by measuring the fullness of the transmission buffer
• CPC Class Codes: H04N 19/16 for a given display mode, e.g. for interlaced or progressive display mode
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/577 Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

An adaptive blocking coding system selects an effective blocking of an input image signal to be encoded in accordance with the correlation between fields, even if motion is detected between the fields. The blocking patterns include an individual field blocking, a non-interlace blocking, a split blocking and an inverted split blocking. Further, the coding system searches for motion from both odd and even fields of a frame for producing a motion compensated prediction signal in order to provide high-efficient coding.

Claims

1. A predictor for a system for communicating digital video signals, the predictor producing an output predictive signal for combination with an input signal to produce a video output signal comprising:

a video memory for storing a previously input video signal as field signals obtained by dividing a frame of said previously input signal into a plurality of fields;

means for outputting a plurality of predictive signals which predict a change of the input video signal based on the signals stored in said video memory; and

means for interpolating between at least two of the plurality of predictive signals and for providing an interpolated predictive signal which is different from other predictive signals, said interpolated predictive signal being supplied by said predictor as the output predictive signal to facilitate interpolative prediction.

2. The predictor of claim 1 further comprising:

a switch for receiving at least one of the predictive signals from said means for outputting and the interpolated predictive signal from said means for interpolating for selecting one of said predictive signals.

3. The predictor of claim 1 wherein said video memory includes first and second field memories.

4. The predictor of claim 2 wherein said switch selects one of said predictive signals having the lowest encoded signal quantity.

5. The predictor of claim 1 wherein the interpolation means produces the interpolated predictive signal by computing the arithmetic mean of the plurality of the predictive signals from said means for outputting.