Abstract
In this paper, a new design scheme of multi-dimensional linear-phase lapped orthogonal transform (LOT) for image and audio coding is proposed. LOT basis functions described by (N×2N) matrix can be generated by rotation model of Nth-order normalized orthogonal vectors in 2N-dimensional orthogonal space. By using this model, the minimum numbers of parameters which optimize coding gain were already reported. We examined the relation between rotational parameters and coding gain, and investigated the sequence of rotational operations, which distribute the power of LOT bases from center to edge. By eliminating the parameters which have low value and low sensitivity, substantial number of parameters can be reduced without the loss of coding gain. Furthermore several design examples of LOT are given to validate the proposed scheme.
