Parallelized 45 degrees rotated image integration

In [1] Lienhart and Maydt introduced the calculation of rotated Haar-Wavelets by 45°. They showed that the extended set of possible wavelets improves the object recognition method of Viola et al. [2]. In this paper, we introduce a novel integral image structure which holds the information of a standard and a 45° rotated integral image. We use this image structure to improve a simple and efficient corner detector by Schweitzer and Wuensche [3] based on Haar wavelets in terms of rotational invariance and define an orientation function. Additionally, we focus on parallelization and remove the recursive character of [1] to make the method suitable for GPUs.