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GrapeCity.Documents.Imaging Assembly / GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.quantization.dequantizer Namespace / StdDequantizerParams Class / nStep Field

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    nStep Field
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    The quantization step for non-reversible systems, normalized to a dynamic range of 1, for each resolution level and subband, as derived from the exponent-mantissa representation in the codestream. The first index is the resolution level, and the second the subband index (within the resolution level), as specified in the Subband class. When in derived quantization mode only the first resolution level (level 0) appears.

    The true step size D is obtained as follows: D=(2^R)*D', where 'R=ceil(log2(dr))' and 'dr' is the dynamic range of the subband samples, in the corresponding subband.

    This value is 'null' for reversible systems (i.e. there is no true quantization, 'D' is always 1).

    In general the index of the first subband in a resolution level is not 0. The steps appear, within each resolution level, at their subband index, and not in the subband order starting from 0. For instance, if resolution level 3, the first subband has the index 16, then the step of the subband is nStep[3][16], not nStep[3][0].

    Syntax
    'Declaration
     
    Public nStep As System.Single[]()
    public System.Single[][] nStep
    See Also