dct.py 文件源码

def _parse_mask(mask):
    r"""
    Interprets a string mask to return the number of coefficients to be kept
    and the indices of the first and last ones in the zig-zagged flattened DCT matrix
    Example: '1-44' returns 44, first=1, last=44
    Parameters
    ----------
    mask

    Returns
    -------

    """
    tmp = mask.split('-')
    first = int(tmp[0])
    last = int(tmp[1])
    ncoeffs = last-first+1
    return ncoeffs, first, last