18.13.2.2 Algorithms (2D Wavelet Reconstruction)
Similar to 2D wavelet decomposition, dwt2 is separable; thus it can broken down to a series of 1D filtering and upsampling operations, as shown in the diagram below:
/Algorithm_IDWT2.png?v=14172)
Note that the filters used for reconstruction are determined by the chosen wavelet and the computation is implemented with a NAG function: nag_idwt2( ).