Moving image signal coding system

Claim 1

A system of coding moving image signals for producing a predictive error signal by a predictive coding based on inter-frame correlation and quantizing by a quantization means (6), the produced predictive error signal for each block of a picture frame constituted by N lines of M pixels, said system comprising a block coding/­non-coding decision means (2A)for calculating a first evaluation value Sm of the predictive error signal for each block of the picture frame and deciding that a block non-coding is applicable when the first evaluation value Sm is less than a first threshold value T₁, and deciding that a block coding is applicable when the first evaluation value Sm is greater than the first threshold value T₁, said predictive error signal not being transmitted when the result of said decision is for a block non-coding, and said predictive error signal being quantized and transmitted when the result of said decision is for a block coding.

Claim 2

A system of coding moving image signals for producing a predictive error signal by a predictive coding based on inter-frame correlation and quantizing by a quantization means (6), the produced predictive error signal for each block of a picture frame constituted by N lines of M pixels, said system comprising a block coding/­non-coding decision means (2A)for calculating a first evaluation value Sm of the predictive error signal for each block of the picture frame and deciding that a block non-coding is applicable when the first evaluation value Sm is less than a first threshold value T₁, and deciding that a block coding is applicable when the first evaluation value Sm is greater than the first threshold value T₁, said predictive error signal not being transmitted when the result of said decision is for a block non-coding, and said predictive error signal being quantized and transmitted when the result of said decision is for a block coding.

Claim 5

A system of coding moving image signals for producing a predictive error signal by a predictive coding based on inter-frame correlation and quantizing by quantization means (6)the produced predictive error signal per each block of a picture frame constituted by N lines of M pixels, said system comprising: block coding/non-­coding decision mean (2A)for calculating a first evaluation value Sm of the predictive error signal per each block of the picture frame and deciding that a block non-coding is applicable when the first evaluation value Sm is less than a predetermined first threshold value T₁, and deciding that a block coding is applicable when the first evaluation value Sm is greater than the first threshold value T₁, and inter-frame/intra-frame selection means (2B) for calculating a first evaluation value Sm of the predictive error signal for each block of the picture frame and a second evaluation signal Si representing the evaluation of a block with regard to an input picture signal, for comparing the calculated first (Sm) and second (Si) evaluation values, and for adopting the predictive error signal where Sm < T₂, where T₂ is a second threshold value, or Sm ≦ Si, and adopting the present input picture signal in other cases, preventing the transmission of the predicted error signal when the result of a decision by said blocking coding/non-coding decision means (2A) is for a non-coding and the result of a selection by said inter-frame/intra-frame selection means (2B) is for an intra-frame, and transmitting the predicted error signal when the result of a decision by said block coding/non-­coding decision means (2A)is for a coding and the result of a selection by said inter-frame/intra-frame selection means (2B) for an inter-frame.

Claim 6

A system of coding moving image signals for producing a predictive error signal by a predictive coding based on inter-frame correlation and quantizing by quantization means (6)the produced predictive error signal per each block of a picture frame constituted by N lines of M pixels, said system comprising: block coding/non-­coding decision mean (2A)for calculating a first evaluation value Sm of the predictive error signal per each block of the picture frame and deciding that a block non-coding is applicable when the first evaluation value Sm is less than a predetermined first threshold value T₁, and deciding that a block coding is applicable when the first evaluation value Sm is greater than the first threshold value T₁, and inter-frame/intra-frame selection means (2B) for calculating a first evaluation value Sm of the predictive error signal for each block of the picture frame and a second evaluation signal Si representing the evaluation of a block with regard to an input picture signal, for comparing the calculated first (Sm) and second (Si) evaluation values, and for adopting the predictive error signal where Sm < T₂, where T₂ is a second threshold value, or Sm ≦ Si, and adopting the present input picture signal in other cases, preventing the transmission of the predicted error signal when the result of a decision by said blocking coding/non-coding decision means (2A) is for a non-coding and the result of a selection by said inter-frame/intra-frame selection means (2B) is for an intra-frame, and transmitting the predicted error signal when the result of a decision by said block coding/non-­coding decision means (2A)is for a coding and the result of a selection by said inter-frame/intra-frame selection means (2B) for an inter-frame.

Claim 9

A system according to claims 4 and 5, wherein an instruction of orthogonal transformation of 1/2 M × 1/2 N, 1/2 M × N, or M × 1/2 N is delivered from said coding/non-coding decision means (2A) when the coding sub-block or sub-blocks are one or two of the block to which said sub-block or sub-blocks belong.