The oblique extension principle introduced in [3, 5] is a general procedure to construct tight wavelet frames and their associated filter banks. Symmetric tight framelet filter banks with two high-pass filters have been studied in [13, 16, 17]. Tight framelet filter banks with or without symmetry have been constructed in [1]–[21] and references therein. This paper is largely motivated by severa...

In this contribution, discrete semiclassical orthogonal polynomials of class s ≤ 2 are studied. By considering all possible solutions the Pearson equation, we obtain canonical families in each class. We also consider limit relations between these and other polynomials.