Gaze-contingent systems minimize bandwidth requirements by displaying high-resolution imagery within eye-slaved regions of interest (ROIs) of limited spatial extent. The parafoveal resolution transitions must be sufficiently smooth to render degradation effects imperceptible. In this paper, a wavelet image filtering scheme is presented which preserves high resolution in ROIs matching foveal vision, and gradually degrades resolution in the periphery. The method permits the representation of multiple ROIs extending previous work based on MIP-mapping to the wavelet domain. Degradation is achieved through wavelet coefficient scaling following Voronoi partitioning of the image plane. Three variants of peripheral degradation are offered, including one matching human visual acuity. Reconstruction examples of images processed with the Haar and Daubechies-6 wavelets are provided. Results from gaze-contingent experiments, conducted to test perceived impairment of degraded image sequences, are summarized suggesting imperceptible degradation effects.
Andrew T. Duchowski,
"Representing multiple regions of interest with wavelets", Proc. SPIE 3309, Visual Communications and Image Processing '98, (9 January 1998); doi: 10.1117/12.298411; https://doi.org/10.1117/12.298411