Prosecution Insights
Last updated: April 19, 2026
Application No. 18/568,155

CODING OF LAST SIGNIFICANT COEFFICIENT IN A BLOCK OF A PICTURE

Non-Final OA §103
Filed
Dec 07, 2023
Examiner
HESS, MICHAEL J
Art Unit
2481
Tech Center
2400 — Computer Networks
Assignee
Interdigital Ce Patent Holdings SAS
OA Round
3 (Non-Final)
44%
Grant Probability
Moderate
3-4
OA Rounds
3y 1m
To Grant
52%
With Interview

Examiner Intelligence

Grants 44% of resolved cases
44%
Career Allow Rate
183 granted / 418 resolved
-14.2% vs TC avg
Moderate +8% lift
Without
With
+7.7%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
66 currently pending
Career history
484
Total Applications
across all art units

Statute-Specific Performance

§101
4.6%
-35.4% vs TC avg
§103
56.8%
+16.8% vs TC avg
§102
10.3%
-29.7% vs TC avg
§112
20.8%
-19.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 418 resolved cases

Office Action

§103
DETAILED ACTION Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 12/08/2025 has been entered. Response to Arguments In view of the amendments to the independent claims, the rejection under 35 U.S.C. 112(b) is withdrawn. Remarks, 7. In view of Examiner’s review of the Specification in light of the amendments made to the independent claims, the rejection under 35 U.S.C. 112(a) is withdrawn. Remarks, 7. On page 7 of the Remarks, Applicant contends the rejection under 35 U.S.C. 103 is moot in view of the amendments. Examiner agrees. The rejection now relies on the additional teachings of Piao, especially when combined with the teachings of Koo, to teach or suggest the features added by way of amendment. Specifically, Koo teaches that when a zero-out region is defined, the coding of the X, Y coordinates of the last significant coefficient can be coded according to the smaller width and height of the zero-out block. Koo’s teachings would still indicate that the coding of the last significant coefficient would represent a distance from the top-left DC coefficient as in conventional coding. Piao, however, teaches that it can be more efficient to code the last significant coefficient using as the origin the bottom-right high-frequency coefficient such that the x, y coordinate information represents smaller values from said changed origin. Therefore, the combination of the teachings of Koo and Piao teaches or suggests Applicant’s features added by way of amendment. Applicant’s published paragraphs [0065] or [0127] seem instructive and mirrors the disclosure of Piao. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claims 1–3, 5–7, 9–11, 13–15, 19, and 21–28 are rejected under 35 U.S.C. 103 as being unpatentable over Koo (US 2022/0159276 A1), Zhao (US 2019/0246142 A1), and Piao (US 2016/0050426 A1). Regarding claim 1, the combination of Koo, Zhao, and Piao teaches or suggests a method comprising: determining that a zeroing process is applied to a block of transform coefficients (Koo, ¶ 0011: teaches zero-out blocks are determined according to signaling (e.g. flags) in the bitstream, such as whether MTS is applied or not; While Koo teaches zero-out sizes based on MTS, which Examiner interprets under BRI as a zeroing process, the prior art describes zeroing processes beyond merely zero-out size; Zhao, ¶¶ 0105 and 0106: teaches determining a zero-out process, e.g. number of coefficients to zero-out, based on transform type, but also teaches other methods; Zhao, e.g. ¶¶ 0105, 0110, 0112, and 0123: teaches several zero-out methods in addition to simply determining the number of coefficients to zero-out); determining a position of a last coefficient in scanning order non-zeroed out by the zeroing process (Koo, Abstract: explains the zero-out block is the smaller sub-block that has significant (i.e. non-zero) coefficients and that the rest of the block is zeroed-out; Koo, ¶¶ 0017 and 0150: teaches the last significant coefficient signaling is limited to the smaller region that is not zeroed-out; Koo, ¶¶ 0203–0204: teaches the width and height of the transform block can be changed (reduced) to coincide with the smaller non-zero out size and that the position of the last significant coefficient can be coded based on the new smaller size rather than the larger, full block size using, for example log2ZoTbWidth, rather than log2TbWidth); decoding a distance from a position of a last significant coefficient of the block in scanning order to the determined position (Koo, e.g. ¶¶ 0187 and 0233: teaches the last significant coefficient coordinate information expresses the distance in the x and y directions; The skilled artisan knows the “origin point” for the x and y directions are typically the top corner of the block; However, in the same field of endeavor, Piao, ¶¶ 0003 and 0029: teaches the distance between the last significant coefficient and a position (either a low frequency position like the top-left corner or a high frequency position like the bottom-right corner) may be determined; see also Piao, ¶ 0035: teaching the position of the last significant coefficient is a value corresponding to a distance from a high frequency region of the coding unit to the last position); determining the position of the last significant coefficient of the block based on the distance and the determined position (Koo, e.g. ¶¶ 0187 and 0233: teaches the last significant coefficient coordinate information expresses the distance in the x and y directions; The skilled artisan knows the “origin point” for the x and y directions are typically the top corner of the block); and reconstructing the block of transform coefficients based on the position of the last significant coefficient of the block (Koo, e.g. ¶¶ 0062, 0069, and 0070: teaches the point of the coding algorithm is to reconstruct the block). One of ordinary skill in the art, before the effective filing date of the claimed invention, would have been motivated to combine the elements taught by Koo, with those of Zhao, because both references are drawn to the same field of endeavor such that one wishing to practice zeroing out coefficients would be led to their relevant teachings and because although Koo may only describe zero-out processes with respect to zero-out size and based on transform kernel, Zhao explains the skilled artisan would be led to consider even more sophisticated zero-out processes. Thus, the combination amounts to a mere combination of prior art elements, according to known methods, to yield a predictable result. This rationale applies to all combinations of Koo and Zhao used in this Office Action unless otherwise noted. One of ordinary skill in the art, before the effective filing date of the claimed invention, would have been motivated to combine the elements taught by Koo and Zhao, with those of Piao, because all three references are drawn to the same field of endeavor such that one wishing to practice coefficient coding would be led to their relevant teachings and because Piao explains how Koo may code the last significant coefficient of the resized zero-out region so that the last significant coefficient can more efficiently be coded from the higher frequency position (bottom-right) rather than the less efficient low frequency position (top-left). Thus, because the prior art solutions were separately known in the same field of endeavor, the combination amounts to a mere combination of prior art elements, according to known methods, to yield a predictable result. This rationale applies to all combinations of Koo, Zhao, and Piao used in this Office Action unless otherwise noted. Regarding claim 2, the combination of Koo, Zhao, and Piao teaches or suggests the method of claim 1, wherein determining that the zeroing process is applied to the block of transform coefficients comprises determining that a zeroing process is applied based on a type of transform process applied to the block (Zhao, ¶¶ 0105 and 0106: teaches determining a zero-out process, e.g. number of coefficients to zero-out, based on transform type; Zhao, e.g. ¶¶ 0105, 0110, 0112, and 0123: teaches several zero-out methods in addition to simply determining the number of coefficients to zero-out). Regarding claim 3, the combination of Koo and Zhao teaches or suggests the method of claim 1, comprising determining a type of zeroing process based on a type of transform process applied to the block (Zhao, ¶¶ 0105 and 0106: teaches determining a zero-out process, e.g. number of coefficients to zero-out, based on transform type; Zhao, e.g. ¶¶ 0105, 0110, 0112, and 0123: teaches several zero-out methods in addition to simply determining the number of coefficients to zero-out). Claim 5 lists the same elements as claim 1, but is drawn to the corresponding encoding method rather than the decoding method. Therefore, the rationale for the rejection of claim 1 applies to the instant claim. Claim 6 lists the same elements as claim 2, but is drawn to the corresponding encoding method rather than the decoding method. Therefore, the rationale for the rejection of claim 2 applies to the instant claim. Claim 7 lists the same elements as claim 3, but is drawn to the corresponding encoding method rather than the decoding method. Therefore, the rationale for the rejection of claim 3 applies to the instant claim. Claim 9 lists the same elements as claim 1, but is drawn to a device rather than a method. Therefore, the rationale for the rejection of claim 1 applies to the instant claim. Claim 10 lists the same elements as claim 2, but is drawn to a device rather than a method. Therefore, the rationale for the rejection of claim 2 applies to the instant claim. Claim 11 lists the same elements as claim 3, but is drawn to a device rather than a method. Therefore, the rationale for the rejection of claim 3 applies to the instant claim. Claim 13 lists the same elements as claim 5, but is drawn to a device rather than a method. Therefore, the rationale for the rejection of claim 5 applies to the instant claim. Claim 14 lists the same elements as claim 6, but is drawn to a device rather than a method. Therefore, the rationale for the rejection of claim 6 applies to the instant claim. Claim 15 lists the same elements as claim 7, but is drawn to a device rather than a method. Therefore, the rationale for the rejection of claim 7 applies to the instant claim. Claim 19 lists the same elements as claim 1, but is drawn to a CRM rather than a method. Therefore, the rationale for the rejection of claim 1 applies to the instant claim. Regarding claim 21, the combination of Koo, Zhao, and Piao teaches or suggests the method of claim 1, wherein decoding the distance comprises decoding a first distance in a horizontal direction and a second distance in a vertical direction (Koo, e.g. ¶¶ 0187 and 0233: teaches the last significant coefficient coordinate information expresses the distance in the x and y directions). Regarding claim 22, the combination of Koo, Zhao, and Piao teaches or suggests the method of claim 21, wherein determining the position of the last significant coefficient of the block based on the distance and the determined position comprises: subtracting the first distance from a horizontal component of the determined position to obtain a first component of the position of the last significant coefficient of the block; and subtracting the second distance from a vertical component of the determined position to obtain a second component of the position of the last significant coefficient of the block (Koo, e.g. ¶¶ 0187 and 0233: teaches the last significant coefficient coordinate information expresses the distance in the x and y directions; Koo, Abstract: explains the zero-out block is the smaller sub-block that has significant (i.e. non-zero) coefficients and that the rest of the block is zeroed-out; Koo, ¶¶ 0017 and 0150: teaches the last significant coefficient signaling is limited to the smaller region that is not zeroed-out; Koo, ¶¶ 0203–0204: teaches the width and height of the transform block can be changed (reduced) to coincide with the smaller non-zero out size and that the position of the last significant coefficient can be coded based on the new smaller size rather than the larger, full block size using, for example log2ZoTbWidth, rather than log2TbWidth; Piao, ¶ 0030: teaches the position information can be coordinate values with respect to the last position and the “second” point origin wherein the second point origin is the high frequency bottom-right corner rather than the typical low frequency top-left corner; see also treatment of claim 1). Claim 23 lists the same elements as claim 21, but is drawn to the corresponding encoding method rather than the decoding method. Therefore, the rationale for the rejection of claim 21 applies to the instant claim. Claim 24 lists the same elements as claim 22, but is drawn to the corresponding encoding method rather than the decoding method. Therefore, the rationale for the rejection of claim 22 applies to the instant claim. Claim 25 lists the same elements as claim 21, but is drawn to a device rather than a method. Therefore, the rationale for the rejection of claim 21 applies to the instant claim. Claim 26 lists the same elements as claim 22, but is drawn to a device rather than a method. Therefore, the rationale for the rejection of claim 22 applies to the instant claim. Claim 27 lists the same elements as claim 23, but is drawn to a device rather than a method. Therefore, the rationale for the rejection of claim 23 applies to the instant claim. Claim 28 lists the same elements as claim 24, but is drawn to a device rather than a method. Therefore, the rationale for the rejection of claim 24 applies to the instant claim. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. M. Koo, M. Salehifar, J. Lim, S. Kim, “CE 6-1.1 (c,d): Fast DST-7/DCT-8 based on DFT and 32 point MTS based on skipping high frequency coefficients,” document Joint Video Experts Team of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29/WG 11, JVET-L0132, Macao, CN, Oct. 2018. Lee (US 2021/0274197 A1) teaches a zero-out region (Fig. 24 and accompanying language) and that the last significant coefficient is only with respect to the non-zero out region and that significant coefficients could have been in the zero-out region that was zeroed-out, i.e. skipped (¶¶ 0339–0340). Lee also teaches a syntax element for a last significant coefficient position prefix that adjusts the last coefficient to be outside the zero-out region such that the maximum range of the position is limited to a smaller value thus achieving bit savings (¶ 0340 and Figs. 21–23). M. Koo, M. Salehifar, “CE 6.1.11: AMT replacement and restriction”, Joint Video Exploration Team (JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC1/SC 29/WG 11 JVET-K0096, 11th meeting, Ljubljana, SI, 10-18 July 2018. Sole et al., "Transform Coefficient Coding in HEVC, IEEE Transactions on Circuits and Systems for Video Technology, Dec. 2012. Section IV(A) teaches the conventional process of coding the last significant coefficient position includes a prefix part. LeLeannec (US 2020/0382810 A1) teaches the conventional process of coding the last significant coefficient position includes a prefix part (e.g. ¶ 0075). Nalci (US 2020/0396487 A1) teaches zero-out and restricting the last coefficient to be within the bounds of the region not zeroed-out, including possibly skipping the signaling of the last coefficient (e.g. ¶¶ 0035, 0037, and 0107). Koo (US 2022/0086490 A1) teaches the width and height of the transform block can be changed (reduced) to coincide with the smaller non-zero out size and that the position of the last significant coefficient can be coded based on the new smaller size rather than the larger, full block size (¶ 0322) and teaches the use of, for example log2ZoTbWidth, rather than log2TbWidth for zeroed out blocks (e.g. ¶ 0369). Strom (US 2015/0281706 A1) teaches the last significant coefficient position is signaled using the origin as the top-left corner of the block (¶ 0009). Wang (US 2014/0064365 A1) teaches the last significant coefficient is coded by its coordinates (x, y) relative to the top-left corner (¶ 0126). Any inquiry concerning this communication or earlier communications from the examiner should be directed to Michael J Hess whose telephone number is (571)270-7933. The examiner can normally be reached on Mon - Fri 9:00am-5:30pm. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, William Vaughn can be reached on (571)272-3922. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. MICHAEL J. HESS Primary Examiner Art Unit 2481 /MICHAEL J HESS/Primary Examiner, Art Unit 2481
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Prosecution Timeline

Dec 07, 2023
Application Filed
Apr 14, 2025
Non-Final Rejection — §103
Jul 14, 2025
Response Filed
Sep 05, 2025
Final Rejection — §103
Dec 08, 2025
Request for Continued Examination
Dec 19, 2025
Response after Non-Final Action
Mar 18, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
44%
Grant Probability
52%
With Interview (+7.7%)
3y 1m
Median Time to Grant
High
PTA Risk
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