# opencv 4.13.0 — OpenCV 4.13.0 - Product: opencv (https://whatsnew.fyi/product/opencv) - Vendor: opencv - Date: 2025-12-31 - Version: 4.13.0 - Original notes: https://github.com/opencv/opencv/releases/tag/4.13.0 - Permalink: https://whatsnew.fyi/product/opencv/releases/4.13.0 What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog. Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'. --- - **added** — Added CVBenchmark, an unbiased CPU benchmark providing evaluation of different CPUs in real-world computer vision and AI workloads - **changed** — Modified Input/OutputArray methods to handle std::vector or std::vector> in a more accurate way - **changed** — Made cuda::GpuMatND compatible with InputArray/OutputArray - **changed** — Forced output type for empty matrices where it is defined in API - **added** — Added std::vector length check to Input/OutputArray - **added** — Added 16-bit LUT and corresponding HAL entrypoint - **added** — Added cv::Mat::copyAt for ROI operation - **added** — Added support for parsing null values and backslash in JSON parser in cv::FileStorage - **fixed** — Fixed cv::solveCubic numerical instability via coefficient normalization - **fixed** — Fixed tempfile race condition on Windows - **changed** — Dropped OPENCV_FOR_OPENMP_DYNAMIC_DISABLE environment variable in favor of standard OMP_DYNAMIC - **changed** — Enabled fp16 conversions but disabled NEON FP16 arithmetics on Windows for ARM - **fixed** — Fixed dot product accumulation causing NORM test failures on Windows ARM64 - **fixed** — Fixed missing vec_cvfo on IBM POWER9 due to unavailable VSX float64 conversion - **fixed** — Fixed in-place flip in HAL for RISC-V RVV - **added** — Added inRange HAL entry point - **added** — Added Iterative Phase Correlation to imgproc module - **added** — Added cv::minEnclosingConvexPolygon - **fixed** — Fixed overflow in connected components - **fixed** — Corrected cv::minAreaRect to follow documentation by forcing angle to range [-90, 0) *December, 2025* New Year update for OpenCV 4.x has been released. - CVBenchmark - An unbiased CPU benchmark by OpenCV (https://github.com/opencv/cvbenchmark) that provides an evaluation of different CPUs in real-world computer vision and AI workloads is released. - Core module: - Modified Input/OutputArray methods to handle 'std::vector' or 'std::vector>' in more accurate way [#28242](https://github.com/opencv/opencv/issues/28242) - Made `cuda::GpuMatND` compatible with InputArray/OutputArray [#23913](https://github.com/opencv/opencv/issues/23913) - Forced output type for empty matrices where it's defined in API [#27972](https://github.com/opencv/opencv/issues/27972) - Added `std::vector` length check Input/OutputArray [#27817](https://github.com/opencv/opencv/issues/27817) - Added 16-bit LUT and corresponding HAL entrypoint [#27890](https://github.com/opencv/opencv/issues/27890), [#27911](https://github.com/opencv/opencv/issues/27911) - Add `cv::Mat::copyAt` for for ROI operation [#27318](https://github.com/opencv/opencv/issues/27318) - Extended JSON support in cv::FileStorage: `null` parsing [#27579](https://github.com/opencv/opencv/issues/27579) and - Added support parsing null in JSON parser in cv::FileStorage [#27579](https://github.com/opencv/opencv/issues/27579) and back slash "\" support [#27587](https://github.com/opencv/opencv/issues/27587) - Fixed `cv::solveCubic` numerical instability via coefficient normalization [#28117](https://github.com/opencv/opencv/issues/28117) - Fixed tempfile race condition on Windows [#28087](https://github.com/opencv/opencv/issues/28087) - Restore parallel framework name on failure attempt [#27802](https://github.com/opencv/opencv/issues/27802) - Dropped OPENCV_FOR_OPENMP_DYNAMIC_DISABLE environment variable in favor of standard OMP_DYNAMIC [#28122](https://github.com/opencv/opencv/issues/28122) - Enabled fp16 conversions, but disabled NEON FP16 arithmetics on Windows for ARM [#27897](https://github.com/opencv/opencv/issues/27897) - Fixed dot product accumulation causing NORM test failures on Windows ARM64 [#28211](https://github.com/opencv/opencv/issues/28211) - Added several performance optimizations for Windows on ARM: [#27575](https://github.com/opencv/opencv/issues/27575), [#27596](https://github.com/opencv/opencv/issues/27596) - Fixed missing vec_cvfo on IBM POWER9 due to unavailable VSX float64 conversion [#27990](https://github.com/opencv/opencv/issues/27990) - Fix in-place flip in HAL for RISC-V RVV [#28180](https://github.com/opencv/opencv/issues/28180) - Added inRange HAL entry point [#27854](https://github.com/opencv/opencv/issues/27854) - Disabled IPP with AVX512 in cv::compare because of performance regression [#28311](https://github.com/opencv/opencv/issues/28311) - Imgproc module: - Added Iterative Phase Correlation [#28146](https://github.com/opencv/opencv/issues/28146), [paper](https://iopscience.iop.org/article/10.3847/1538-4365/ab63d7) - Added `cv::minEnclosingConvexPolygon` [#27369](https://github.com/opencv/opencv/issues/27369) - Improved near-zero convexity handling in `cv::convexHull` [#28043](https://github.com/opencv/opencv/issues/28043) - Kept `cv::convexHull` output indices monotone if possible [#28163](https://github.com/opencv/opencv/issues/28163) - Fixed overflow in connected components [#27582](https://github.com/opencv/opencv/issues/27582) - Corrected `cv::minAreaRect` to follow documentation (force angle to range [-90, 0)) [#28051](https://github.com/opencv/opencv/issues/28051). Versions of OpenCV with different angle range are 4.5.1-4.12.0. Expected angle range documented first time in 4.12.0 release. - Increased minAreaRect accuracy with doubles [#28149](https://github.com/opencv/opencv/issues/28149) - Added `cv::CLAHE::BitShift` option [#28014](https://github.com/opencv/opencv/issues/28014) - Fixed `cv::minEnclos _[Truncated at 4000 characters — full notes: https://github.com/opencv/opencv/releases/tag/4.13.0]_