An apparatus and a method for forming a data structure that improves error
resilience when applied to the coding of hierarchical subband decomposed
coefficients, e.g., wavelet transform coefficients. The texture unit is
defined as comprising only those AC transform coefficients that are
located in one or more slices in a single subband. The texture unit is
defined as comprising only those AC transform coefficients that are
across "n" subbands, where "n" is smaller number than the total number of
"N" levels of decomposition. A texture unit can also be defined as
comprising only those bits from the DC transform coefficients that form a
single bitplane.