Patent ID: 6859562

Claim:
A coded data length detection apparatus comprising: a frequency conversion means for frequency-converting a two dimensional arranged image data; a quantization coefficient providing means for providing a plurality of groups of quantization coefficients, each group of quantization coefficients comprising a plurality of blocks of quantization coefficients, discretely arranged in a two dimensional lattice, each block being defined as a unit of the minimum coding unit, one group of quantization coefficients being used for coding the image data; a quantization means for reading one group of quantization coefficients among the plurality of groups of quantization coefficients from the quantization coefficients providing means and quantizating the data frequency-converted at the frequency conversion means by using the read one group of quantization coefficients; a coding means for coding the quantizated result; a coded data length calculation means for calculating a substantial data length of the coded results; and a control means for repeatedly operating the quantization coefficient providing means, the quantization means, the coding means and the coded data length calculation means by the number of the plurality of groups of the quantization coefficients to carry out the quantization, the coding and coded data length calculation on the frequency-converted data obtained at the frequency conversion means and the respective group of the quantization coefficients, to thereby obtain a plurality of data lengths of the plurality of coded results.