Patent ID: 7983338

Claim:
A progressive lossless video coding method that performs video coding which allows decoding that matches an original signal comprising: a step that inputs a residual signal obtained by subtracting a prediction signal from an original signal for each block of an image signal, the prediction signal conforming to a predetermined lossy video coding scheme and being obtained by space prediction in intra-frame coding or by time prediction in inter-frame coding; a step that determines transform coefficients obtained by applying orthogonal transformation on the residual signal and quantization coefficients obtained by quantizing the transform coefficients based on the lossy video coding scheme; a step that identifies existential space of transformed coefficients established from the quantization coefficients, and quantization parameters and quantization methods used during quantization; a validity judging step that judges whether grid points in the existential space of the transform coefficients are valid as a result of orthogonal transformation of the residual signal; an enumerating step that searches, in a predetermined grid point order, grid points for which the judgment is valid from the grid points in the existential space of the transform coefficients, and enumerates the grid points thus searched; a step that assigns serial numbers in the order of enumeration to enumerated grid points; a step that acquires serial numbers of grid points matching the transform coefficients of the residual signal from the enumerated grid points, and a step that codes and outputs the serial numbers of the grid points matching the transform coefficients of the residual signal.