摘要:
In an encoding system responsive to a sequence of coefficient signals which results from a predetermined linear transform and which is divided into a sequence of blocks, anterior processing is carried out prior to quantization about the coefficient signals in each block to determine a significant area of the coefficient signals by comparing each level of the coefficient signals with a threshold level. Only the coefficient signals within the significant area are judged to be valid and produced as a sequence of significant coefficient signals from a classifying circuit (20) to be quantized by a quantizer (15) into a sequence of quantized signals. The quantized signal sequence is subjected to posterior processing to produce a sequence of encoded signals. The significant area may be decided by the use of a selected one of zone detection, zigzag scanning, and adaptive scanning. In the posterior processing, the quantized signals may be encoded into the encoded signals by the use of a plurality of code sets or tables.
摘要:
A motion compensation difference interframe or inter-frame coding system having a block data redundancy compression and coding unit (30a), a PIXEL data coding unit (40) and a prediction data generating unit (20). The block data redundancy compression and coding unit (30a) codes a motion compensated (MC) difference between an input image in a form of a block and a motion predicted image from the prediction data generator unit (20), and transmits a coded data to a receiver. The PIXEL data coding unit (40) receives an error between the MC difference and a decoded MC difference from the block data redundancy compression and coding unit (30a), rearranges the error in the PIXEL data and codes the PIXEL error, when the error is greater than a predetermined value. The PIXEL coded data is also transmitted to the receiver. The prediction data generator unit (20) generates a predicted block data of the motion of the image. The redundancy compression and coding unit (30a) may include a filter circuit (9) rejecting pulse components contained in the MC difference.
摘要:
In an encoder responsive to a sequence of coefficient blocks each of which is composed of a plurality of orthogonal transform coefficients subjected to predictive encoding and orthogonal transform, the coefficient blocks are classified by a classification circuit (55) into a plurality of classes to produce a control signal (CONT) representative of the classes. A quantization unit (60), a code conversion unit (6l), and a coefficient selection unit (62, 64) are controlled by the control signal to select quantization characteristics, code conversion characteristics, and coefficient selection characteristics. The quantization unit comprises a plurality of quantizers corresponding to the quantization characteristics while the code conversion unit and the coefficient selection unit comprise a plurality of code converters and a plurality of selection tables corresponding to the code conversion characteristics and the coefficient selection characteristics, respectively. Consequently, the coefficients are adaptively encoded into a reduced amount of encoded codes on encoding a moving image.
摘要:
In an encoder responsive to a sequence of coefficient blocks each of which is composed of a plurality of orthogonal transform coefficients subjected to predictive encoding and orthogonal transform, the coefficient blocks are classified by a classification circuit (55) into a plurality of classes to produce a control signal (CONT) representative of the classes. A quantization unit (60), a code conversion unit (6l), and a coefficient selection unit (62, 64) are controlled by the control signal to select quantization characteristics, code conversion characteristics, and coefficient selection characteristics. The quantization unit comprises a plurality of quantizers corresponding to the quantization characteristics while the code conversion unit and the coefficient selection unit comprise a plurality of code converters and a plurality of selection tables corresponding to the code conversion characteristics and the coefficient selection characteristics, respectively. Consequently, the coefficients are adaptively encoded into a reduced amount of encoded codes on encoding a moving image.