US 11,943,450 B2
System and method to estimate blockiness in transform-based video encoding
Peter List, Unna (DE); Rakesh Ramachandra, Ilmenau (DE); Werner Robitza, Vienna (AT); Alexander Raake, Berlin (DE); Steve Goering, Menteroda (DE); Ulf Wuestenhagen, Gruenheide (DE); and Bernhard Feiten, Berlin (DE)
Assigned to DEUTSCHE TELEKOM AG, Bonn (DE)
Appl. No. 17/629,481
Filed by DEUTSCHE TELEKOM AG, Bonn (DE)
PCT Filed Jul. 23, 2020, PCT No. PCT/EP2020/070834
§ 371(c)(1), (2) Date Jan. 24, 2022,
PCT Pub. No. WO2021/013946, PCT Pub. Date Jan. 28, 2021.
Claims priority of application No. 19188067 (EP), filed on Jul. 24, 2019.
Prior Publication US 2022/0295074 A1, Sep. 15, 2022
Int. Cl. H04N 19/154 (2014.01); H04N 19/124 (2014.01); H04N 19/18 (2014.01); H04N 19/60 (2014.01); H04N 19/86 (2014.01)
CPC H04N 19/154 (2014.11) [H04N 19/124 (2014.11); H04N 19/18 (2014.11); H04N 19/60 (2014.11); H04N 19/86 (2014.11)] 10 Claims
OG exemplary drawing
 
6. A system for estimating blockiness in a video frame of transform-based video encoding, the system comprising:
data processing means configured to obtain a bitstream of a transform coded video signal, the signal being partitioned into video frames and all operations being performed on a per frame basis, wherein coefficients constituting transforms encoded in the video signal frames are read;
averaging means configured to average the coefficients of the transforms encoded in the bitstream into one averaged transform matrix per transform block size i;
weighting means configured to generate or make available one weighting matrix per averaged transform of block size i, comprising weighting factors, wherein the weighting means are further configured to compute intermediate weighted and averaged transform matrices by processing each averaged transform matrix with the corresponding weighting matrix;
computing means configured to compute all members of each weighted and averaged transform matrix into a single value per transform of block size i, to obtain intermediate signals Bls[i]; and
computing means configured to compute a single value Bl0 by weighting values of the intermediate signals Bls[i] according to an area in the respective video frame and adding up the weighted values of the intermediate signals Bls[i],
wherein the area is the area which the quantity of transform matrices of block size i cover per video frame, wherein this area is dependent on the number of transforms of a specific size i, NTr[i], in the examined frame and the number of pixels each of these transforms covers, and wherein Bl0 is computed using the formula
Bl0=Bls[4×4]*NTr[4×4]+4*Bls[8×8]*NTr[8×8]+16*Bls[16×16]*NTr[16×16]+ . . . ;
wherein blockiness is further estimated as Bl1 using a factor C(QP) dependent on a frame averaged quantization parameter QP and a codec dependent maximum QP, QP_max, where C(QP) is defined as C=exp (5*((QP_max−QP)/QP_max)); and
wherein Bl1=Bl0*C(QP).