EP3082339

• HFI Innovation Inc.since Sep 16, 2016; EPO record ends Jul 1, 2022

[0001] An apparatus and method for content adaptive offset restoration are described. In video processing system, due to various mathematic operations applied to the data, the mean intensity of the processed video data may be shifted from mean intensity of original data. The intensity offset will result in noticeable artifacts. Accordingly adaptive offset restoration is disclosed which derives intensity offset for a region of a picture based on the dynamic characteristics of underlying pixels. According to the characteristics measurement of underlying pixels, the pixels in each region are classified into classes and an intensity offset is determined for each class. The characteristics measurement may be based on pixel patterns at an underlying pixel and the characteristics may be related to edge, peak and valley at the underlying pixel. Alternatively, the characteristics measurement may be based on pixel intensity of an underlying pixel and the pixel intensity is partitioned into multiple bands for classification.