Hybrid reference picture reconstruction method for single and multiple layered video coding systems

A method of generating a picture region, the method comprising:

• providing a first layer comprising a plurality of first layer pictures having a first dynamic range associated with a first bit depth of the first layer pictures;
• providing a second layer comprising a plurality of second layer pictures having a second dynamic range associated with a second bit depth of the second layer pictures;
• wherein the second bit depth is higher than the first bit depth;
• performing a first mode of picture region generation comprising inverse mapping first bit depth data associated to the first dynamic range to second bit depth data associated to the second dynamic range of a region of a first layer picture from the plurality of first layer pictures to generate a first intermediate picture region;
• performing a second mode of picture region generation comprising utilizing a second layer temporal signal from one or more previously decoded pictures in the second layer to generate a second intermediate picture region, the second layer temporal signal comprising one or more pixels from the one or more previously decoded pictures in the second layer, wherein the first intermediate picture region and the second intermediate picture region correspond to the picture region to be generated;
• performing a third mode of picture region generation comprising, for each pixel location in the first intermediate picture region and the second intermediate picture region, computing an average of a pixel value corresponding to the pixel location in the first intermediate picture region and a pixel value corresponding to the same pixel location in the second intermediate picture region to generate a third intermediate picture region;
• and
• selecting as the picture region to be generated one picture region from among the first intermediate picture region, the second intermediate picture region, and the third intermediate picture region based on a metric;
• wherein selecting comprises:
• determining one or more ranges based on characteristics of the inverse mapping from the first dynamic range to the second dynamic range of prior first and second layer pictures, wherein each range is bounded by a pair of threshold pixel values at the first bit depth;
• determining whether or not a mean or other statistic of the region of the picture from the first layer is within one of the determined ranges;
• and if the mean or other statistic of the region of the picture from the first layer is within one of the determined ranges:
• selecting the first intermediate picture region as the picture region to be generated, otherwise selecting the second intermediate picture region as the picture region to be generated.