US 12,003,723 B2
Unified transform type signaling and transform type dependent transform coefficient level coding
Benjamin Bross, Berlin (DE); Phan Hoang Tung Nguyen, Berlin (DE); Paul Keydel, Berlin (DE); Heiko Schwarz, Berlin (DE); Detlev Marpe, Berlin (DE); Thomas Wiegand, Berlin (DE); and Christian Helmrich, Berlin (DE)
Assigned to FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V., Munich (DE)
Filed by FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V., Munich (DE)
Filed on Jun. 13, 2023, as Appl. No. 18/208,952.
Application 18/208,952 is a continuation of application No. 17/362,869, filed on Jun. 29, 2021, granted, now 11,706,413.
Application 17/362,869 is a continuation of application No. PCT/EP2019/087162, filed on Dec. 30, 2019.
Claims priority of application No. 19150112 (EP), filed on Jan. 2, 2019; and application No. 19162406 (EP), filed on Mar. 12, 2019.
Prior Publication US 2023/0328242 A1, Oct. 12, 2023
Int. Cl. H04N 19/12 (2014.01); H04N 19/129 (2014.01); H04N 19/132 (2014.01); H04N 19/176 (2014.01); H04N 19/46 (2014.01)
CPC H04N 19/12 (2014.11) [H04N 19/129 (2014.11); H04N 19/132 (2014.11); H04N 19/176 (2014.11); H04N 19/46 (2014.11)] 9 Claims
OG exemplary drawing
 
1. An apparatus for decoding a picture comprising:
a processor configured to:
select, for a transform block, a transformation out of a predetermined list of transformations comprising an identity transformation and at least one non-identity transformation;
decode, for the transform block, a block of coefficients from a data stream based on the selected transformation, wherein:
to decode the block of coefficients when the selected transformation is a non-identity transformation, the processor is configured to:
decode, from the data stream, position information for acquiring a coefficient position, the position information indicating where along a scanning order traversing all coefficients of the block of coefficients, a non-zero coefficient is encountered first or where along the scanning order a non-zero coefficient is encountered last,
decode first coefficients of the block of coefficients from the data stream, the first coefficients comprise all non-zero coefficients of the block of coefficients and are traversed by the scanning order starting from or up to the coefficient position, and
infer second coefficients of the block of coefficients to be zero, the second coefficients different from the first coefficients,
to decode the block of coefficients when the selected transformation is the identity transformation, the processor is configured to decode all coefficients of the block of coefficients from the data stream;
derive from the block of coefficients a residual sample array for the transform block so that the block of coefficients is related to the residual sample array according to the selected transformation; and
correct a prediction for the transform block using the residual sample array to reconstruct the transform block.