There is included a method and apparatus comprising computer code configured to cause a processor or processors to perform obtaining a leaf node of geometry based point cloud compression (G-PCC) data, splitting the leaf node into a plurality of cuboids, deriving separate triangle soups for each of the cuboids, and coding a plurality of flags respectively for each of the edges of each of the cuboids, where the plurality of flags indicate whether vertices of the separate triangle soups are present on ones of the edges.

In a method to improve backwards compatibility when decoding high-dynamic range images coded in a wide color gamut (WCG) space which may not be compatible with legacy color spaces, hue and/or saturation values of images in an image database are computed for both a legacy color space (say, YCbCr-gamma) and a preferred WCG color space (say, IPT-PQ). Based on a cost function, a reshaped color space is computed so that the distance between the hue values in the legacy color space and rotated hue values in the preferred color space is minimized HDR images are coded in the reshaped color space. Legacy devices can still decode standard dynamic range images assuming they are coded in the legacy color space, while updated devices can use color reshaping information to decode HDR images in the preferred color space at full dynamic range.

In a method to improve backwards compatibility when decoding high-dynamic range images coded in a wide color gamut (WCG) space which may not be compatible with legacy color spaces, hue and/or saturation values of images in an image database are computed for both a legacy color space (say, YCbCr-gamma) and a preferred WCG color space (say, IPT-PQ). Based on a cost function, a reshaped color space is computed so that the distance between the hue values in the legacy color space and rotated hue values in the preferred color space is minimized HDR images are coded in the reshaped color space. Legacy devices can still decode standard dynamic range images assuming they are coded in the legacy color space, while updated devices can use color reshaping information to decode HDR images in the preferred color space at full dynamic range.

A video decoder employs context-adaptive binary arithmetic coding for decoding a video from a data stream. The video decoder determines a parametrization for the context-adaptive binary arithmetic coding.

A video decoder employs context-adaptive binary arithmetic coding for decoding a video from a data stream. The video decoder determines a parametrization for the context-adaptive binary arithmetic coding.

Given an input image in a high dynamic range (HDR) which is mapped to a second image in a second dynamic range using a reshaping function, to improve coding efficiency, a reshaping function generator may adjust the codeword range of the HDR input under certain criteria, such as for noisy HDR images with a relatively-small codeword range. An example of generating a scaler for adjusting the HDR codeword range based on the original codeword range and a metric of the percentage of edge-points in the HDR image is provided. The adjusted reshaping function allows for more efficient rate control during the compression of reshaped images.

A method of decoding a coding unit from a coding tree unit of an image frame from a video bitstream. The method comprises determining a scan pattern for a transform block the scan pattern progressing from a current collection to a next collection of the plurality of collections after completing scanning of the current collection; decoding residual coefficients from the video bitstream according to the scan pattern; determining a multiple transform selection index for the coding unit, decoding the multiple transform selection index from the video bitstream if a last significant coefficient encountered along the scan pattern is at or within a threshold cartesian location of the transform block, and determining the multiple transform selection index to indicate that multiple transform selection is not used if the last significant residual coefficient position of the transform block along the scan pattern outside the threshold location; and transforming the decoded residual coefficients.

A method of decoding a coding unit from a coding tree unit of an image frame from a video bitstream. The method comprises determining a scan pattern for a transform block the scan pattern progressing from a current collection to a next collection of the plurality of collections after completing scanning of the current collection; decoding residual coefficients from the video bitstream according to the scan pattern; determining a multiple transform selection index for the coding unit, decoding the multiple transform selection index from the video bitstream if a last significant coefficient encountered along the scan pattern is at or within a threshold cartesian location of the transform block, and determining the multiple transform selection index to indicate that multiple transform selection is not used if the last significant residual coefficient position of the transform block along the scan pattern outside the threshold location; and transforming the decoded residual coefficients.

This disclosure relates to video coding and more particularly to techniques for signaling picture output resolution for coded video. According to an aspect of an invention, a first flag syntax element indicating whether conformance cropping window offset parameters are present in a sequence parameter set is parsed, wherein the conformance cropping window offset parameters specify a cropping window that is applied to pictures with a width equal to a maximum width and a height equal to a maximum height.

This disclosure relates to video coding and more particularly to techniques for signaling picture output resolution for coded video. According to an aspect of an invention, a first flag syntax element indicating whether conformance cropping window offset parameters are present in a sequence parameter set is parsed, wherein the conformance cropping window offset parameters specify a cropping window that is applied to pictures with a width equal to a maximum width and a height equal to a maximum height.