Packing displacement component sample in the displacement video frame for dynamic mesh coding
An apparatus receives a compressed bitstream including an encoded displacements bitstream and packing method information indicating whether the displacement component samples are packed in ascending order or in descending order. The apparatus video-decodes the encoded displacements bitstream to generate a displacement video frame, wherein padding is added at a bottom of the displacement video frame irrespective of whether the displacement component samples are packed in ascending order or in descending order. The apparatus image-unpacks the displacement video frame to generate an array of quantized displacement wavelet coefficients, inverse-quantizes the array of quantized displacement wavelet coefficients to generate displacement wavelet coefficients, and inverse-wavelet-transforms the displacement wavelet coefficients to generate displacement component samples.
1 . An apparatus comprising:
a communication interface configured to receive a compressed bitstream including an encoded displacements bitstream and packing method information indicating whether displacement component samples are packed in ascending order or in descending order, wherein the displacement component samples are packed in ascending order when the packing method information is equal to a first value, and the displacement component samples are packed in descending order when the packing method information is equal to a second value, wherein the first value is 0 and the second value is 1; and
a processor operably coupled to the communication interface, the processor configured to cause:
decoding the packing method information;
video-decoding the encoded displacements bitstream to generate a displacement video frame;
image-unpacking the displacement video frame to generate an array of quantized displacement wavelet coefficients, wherein the displacement video frame includes padding at a lower area of the displacement video frame irrespective of whether the displacement component samples are packed in descending order;
inverse-quantizing the array of quantized displacement wavelet coefficients to generate displacement wavelet coefficients; and
inverse-wavelet-transforming the displacement wavelet coefficients to generate displacement component samples.
2 . The apparatus of claim 1 , wherein, irrespective of whether the packing method information indicates that the displacement component samples are packed in descending order, an upper area of the displacement video frame includes quantized displacement wavelet coefficients and the lower area of the displacement video frame does not include any quantized displacement wavelet coefficient and includes samples for padding.
3 . The apparatus of claim 2 , wherein image-unpacking the displacement video frame starts from a bottom-right block of the upper area if the packing method information indicates that the displacement component samples are packed in descending order.
4 . The apparatus of claim 3 , wherein the bottom-right block of the upper area includes quantized displacement wavelet coefficients belonging to a lowest level of detail (LOD).
5 . The apparatus of claim 1 , wherein a plurality of packing blocks are placed in the displacement video frame.
6 . The apparatus of claim 5 , wherein the plurality of packing blocks includes one or more non-padded blocks and a partially padded block,
each of the one or more non-padded blocks include quantized displacement wavelet coefficients belonging to a first level of detail (LOD) and do not include any samples for padding, and
the partially padded block includes one or more quantized displacement wavelet coefficients belonging to the first LOD and one or more samples for padding.
7 . The apparatus of claim 6 , wherein the one or more non-padded blocks precede the partially padded block in scan order of blocks, when the packing method information indicates that the displacement component samples are packed in descending order.
8 . The apparatus of claim 7 , wherein the scan order of blocks is reverse raster scan.
9 . The apparatus of claim 6 , wherein the partially padded block precedes one or more fully padded blocks, each of the one or more fully padded blocks does not include any quantized displacement wavelet coefficient to be decoded and includes samples for padding.
10 . The apparatus of claim 6 , wherein each of the one or more non-padded blocks is not allowed to include quantized displacement wavelet coefficients belonging to a second LOD, the second LOD being different from the first LOD.
11 . The apparatus of claim 1 , wherein a plurality of packing blocks are placed in the displacement video frame and a size of the plurality of packing blocks is an integer multiple of a size of a unit block used for configuring a partially or independently decodable region for a video coding standard used by the video-decoding, the integer being equal to or greater than 1.
12 . The apparatus of claim 11 , wherein the partially or independently decodable region for a video coding standard used by the video-decoding is not allowed to include quantized displacement wavelet coefficients belonging to two or more levels of detail.
13 . The apparatus of claim 11 , wherein a size of the unit block is a size of a coding tree unit specified in the video-decoding, when the video-decoding uses High Efficiency Video Coding (HEVC).
14 . The apparatus of claim 11 , wherein a size of the unit block is a size of a macroblock specified in the video-decoding, when the video-decoding uses Advanced Video Coding (AVC).
15 . A method comprising:
receiving a compressed bitstream including an encoded displacements bitstream and packing method information indicating whether displacement component samples are packed in ascending order or in descending order, wherein the displacement component samples are packed in ascending order when the packing method information is equal to a first value, and the displacement component samples are packed in descending order when the packing method information is equal to a second value, wherein the first value is 0 and the second value is 1;
decoding the packing method information;
video-decoding the encoded displacements bitstream to generate a displacement video frame;
image-unpacking the displacement video frame to generate an array of quantized displacement wavelet coefficients, wherein the displacement video frame includes padding at a lower area of the displacement video frame irrespective of whether the displacement component samples are packed in descending order;
inverse-quantizing the array of quantized displacement wavelet coefficients to generate displacement wavelet coefficients; and
inverse-wavelet-transforming the displacement wavelet coefficients to generate displacement component samples.
16 . An apparatus comprising:
a communication interface; and
a processor operably coupled to the communication interface, the processor configured to cause:
encoding packing method information indicating whether displacement component samples are packed in ascending order or in descending order, wherein the displacement component samples are packed in ascending order when the packing method information is equal to a first value, and the displacement component samples are packed in descending order when the packing method information is equal to a second value, wherein the first value is 0 and the second value is 1;
wavelet-transforming displacement component samples to generate displacement wavelet coefficients;
quantizing the displacement wavelet coefficients to generate an array of quantized displacement wavelet coefficients;
image-packing the array of quantized displacement wavelet coefficients to generate a displacement video frame, wherein padding is added at a lower area of the displacement video frame irrespective of whether the displacement component samples are packed in descending order;
video-encoding the displacement video frame to generate an encoded displacements bitstream; and
combining the encoded packing method information and the encoded displacements bitstream into a compressed bitstream.
17 . The apparatus of claim 16 , wherein, when the packing method information indicates that the displacement component samples are packed in descending order, an upper area of the displacement video frame includes quantized displacement wavelet coefficients and a lower area of the displacement video frame does not include any quantized displacement wavelet coefficient and includes samples for padding.
18 . The apparatus of claim 17 , wherein image-packing the displacement video frame starts from a bottom-right block of the upper area if the packing method information indicates that the displacement component samples are packed in descending order.
19 . The apparatus of claim 18 , wherein the bottom-right block of the upper area includes quantized displacement wavelet coefficients belonging to a lowest level of detail (LOD).
20 . The apparatus of claim 16 , wherein a plurality of packing blocks are placed in the displacement video frame and a size of the plurality of packing blocks is an integer multiple of a size of a unit block used for configuring a partially or independently decodable region for a video coding standard used by video-decoding, the integer being equal to or greater than 1.