opencv 4.12.0

July, 2025

Summer update for OpenCV 4.x

• Core Module:

  • Added user-defined logger callback #27154
  • Added reinterpret() method to cv::Mat #25394
  • Fixed empty ND-array construction #27362
  • Fixed bug with int64 support for FileStorage #26846
  • Fixed cv::meanStdDev overflow for large images #26867
  • Useed HAL for cv::mean function too #26895
  • Vectorized cv::normalize / cv::norm #26885
  • Enabled SIMD_SCALABLE for exp and sqrt #26886
  • vectorized normDiff with universal intrinsics #27042
  • Refactored normDiff in hal_rvv and extended with support of more data types #27115
  • Further vectorized copyTo with mask #27145
  • Fix POWN OpenCL implementation #27274
  • Restored legacy universal intrinsics operators in a separate header #27327
  • Improved solveCubuc accuracy: #27331, #27347
  • Deprecated copyData Parameter in cv::UMat construction from std::vector and always copy data #27408

• Imgproc Module:

  • Optimized and reduced memory consumption in cv::findContours #26690, #26834
  • Fixed integer overflow in cv::HoughLinesProbabilistic with very large input images #26744
  • Fixed several potential overflows in image warping #26765, #26776
  • Improved robustness for ellipse fitting #26773
  • Added cv::THRESH_DRYRUN flag to get adaptive threshold values without input thresholding #26836
  • Fixed cv::getPerspectiveTransform for singular case #26926
  • Optimized bayer2Gray with universal intrinsics #26868
  • Added optional mask to cv::threshold #26842
  • Accelerated cv::remap calculation with multi-threading, when cv::WARP_INVERSE_MAP is used #27108
  • Reworked HSV color conversion tables initialization in OpenCL branch to fix possible data raise #27287
  • Fixed bilateral filter's sigma color and sigma space issue #27309
  • Impoved performance of medianblur #27299
  • Added cv::getClosestEllipsePoints function to get the closest point on an ellipse #26299
  • Corrected IPP implementation for cv::distanceTransform results with single thread #27432
  • Fixed cv::matchTemplate with mask crash #26703
  • Added diamond structuring element to morphology operations #27441, #27492
  • Improved cv::intersectConvexConvex accuracy in corner cases #26974

• Calib3d module:

  • Fixed inliers updating in homography estimation #26742
  • Added cv::solvePnPRansac implementation for the fisheye camera model #26669
  • Fixed different marker ordering with cv::findChessboardCornersSBWithMeta and cv::CALIB_CB_LARGER flag.
  • Fixed logical mistake in FilterSpecklesImpl #26996
  • Optimized undistort points for the fisheye camera model #26988
  • Optimized new camera matrix estimation and some related functions #27001
  • Added warning if projected axes are out of camera frame in cv::drawAxes function #27311
  • Added image dimension check to avoid StereoSGBM non-determinism #27305
  • Fixed bugs in SQPNP orthogonalization and simplified column vectors copying #27437

• DNN Module:

  • Added TFLite StridedSllice (without strides but just Slice) and enable strides for TF importers #27273
  • Added fusion handler of conv+eltwise in case of multi-output node (i.e. Split) #27326
  • Added new ops import in TFLite parser: SUB, SQRT, DIV, NEG, SQUARED_DIFFERENCE, SUM #27307
  • Fxied scalars and 1d tensors support in TFLite parser #27307
  • Reduced number of NHWC<->NCHW conversions in TFLite parser #27307
  • Added checks before getting latest pin in Net::Impl::getLatestLayerPin #27353
  • Added OpenVINO NPU support #27363
  • Added more operations to CANN backend #24756

• Objdetect module:

  • Extend ArUcoDetector to run multiple dictionaries in an efficient manner #26934.
  • Fixed rotated aruco marker board generation #26753
  • Fixed incorrect Aruco marker detection near image edge #26968
  • Fixed invalid vector access in QR de/encoder #26532
  • Fix QR code encoder with auto version #27244
  • Aded QRCode ECI encoding support #24426, #27486
  • Made ChAruco board consistency check optional #26824

• Photo Module:

  • Added 16-bit support to cv::fastNlMeansDenoising and updated tests #26831
  • Local decolor pipeline optimization #27041
  • Fixed Triangle Weights used by Debevec algorithm being non zero at extremes #27270
  • Fixed NaNs in HDR Triangle Weights and Tonemapping and Update LDR Ground Truth in tutorial #27396

• VideoIO Module:

  • Fixed invalid custom FFmpeg options handling provided with environment variable #26793
  • Fixed default cv::CAP_PROP_ORIENTATION_ATUO behaviour #26800
  • Improved camera opening performance when with DShow backed, if custom options are provided #26601
  • Added zoom support into Android native camera capture #26837
  • Fixed V4L frame size for non-BGR output #27193
  • Added Orbbec Gemini 330 camera support #27230
  • Fixed cv::VideoWriter failure on writing colorless images #27153
  • Fixed Android setCameraIndex issue #27419

• Imgcodecs:

  • Extended image I/O API with metadata support #27499
  • Added in-memory animation encoding and decoding #27013
  • Added hidden frame support for Animated PNG #27127
  • Added GIF decode and encode for imgcodecs #25691, #26971, #26859, #26738, #26930, #27081, #27138, #27296
  • Added animated WebP Support #25608, #27457
  • Added GDAL multi-channel support #27458
  • Fixed AVIF linkage on Windows #26762
  • Significantly improved PNG and Animated PNG files handing #26849, #26739, #26748, #26782, #26832, #26835, #26848, #26851, #26854, #26915, #27040, #27087, #27297
  • Added several fixes for libspng integration #27314
  • Fixed memory leak in JpegXL decoder #26787
  • Added support for cv::IMREAD_UNCHANGED and other ImreadFlags into JpegXL implementation #26788
  • Implemented imdecode() for JpegXL to directly read from memory #26844
  • Added lossless compression support for JpegXL #27384
  • Fixed cv::imread() implementation for 16-bit png with libspng back-end #27113

• Highgui Module:

  • displayOverlay doesn't disappear after timeout #27082
  • Fix closing of windows when using the Qt backend #27170
  • Fixed QT window resize regression #27282

• G-API module:

  • Workaround for successfull append of OpenVINO Execution Provider: Moved creation of 'Ort::Env' before it #26983
  • Adding AddRgbFeature(), and improving robustness in ComputeRgbDistance #26682
  • Added MS Media Foundation availability check in G-API too #27355

• Video Module: …