In digital computation, it is the discrete sampling sequences of continuous wavelet functions that are used. Using the cascade algorithm, the discrete approximating sequences of scaling and wavelet functions are computed for introducing the mother wavelets without analytical forms into iris feature extraction. By the definition of wavelet packets, the discrete approximating sequences of wavelet packet functions can also be computed to fulfill continuous transform. Using continuous wavelet packet transform based on these sequences, the multi-vanishing moments joint best wavelet packet bases are chosen for eigen-images generation in the eigen-images based correlation recognition. This recognition is implemented by a volume holographic correlation system to take good use of high parallelism of optics. The modified post-processing method using statistic feature can make the algorithm more robust to the errors introduced in optical system. In simulation, with the high precision of digital computation, the identifi