diff --git a/.github/workflows/PR-4.x-ARM64.yaml b/.github/workflows/PR-4.x-ARM64.yaml
new file mode 100644
index 0000000000..b2f5de1025
--- /dev/null
+++ b/.github/workflows/PR-4.x-ARM64.yaml
@@ -0,0 +1,187 @@
+name: PR:4.x ARM64
+
+# TODO: enable pipeline after 4.x update
+on: workflow_dispatch
+
+env:
+  EXTRA_CMAKE_OPTIONS: '-DBUILD_DOCS=ON -DPYTHON_DEFAULT_EXECUTABLE=/usr/bin/python3 -DBUILD_opencv_xfeatures2d=OFF -DBUILD_EXAMPLES=ON -DOPENCV_ENABLE_NONFREE=ON -DENABLE_CCACHE=OFF'
+  OPENCV_TEST_DATA_PATH: '/opencv_extra/testdata'
+  OPENCV_DOCKER_WORKDIR: '/__w/opencv/opencv'
+  PR_AUTHOR: ${{ github.event.pull_request.user.login }}
+  PR_AUTHOR_FORK: ${{ github.event.pull_request.head.repo.full_name }}
+  SOURCE_BRANCH_NAME: ${{ github.head_ref }}
+  TARGET_BRANCH_NAME: ${{ github.base_ref }}
+  ANT_HOME: '/usr/share/ant'
+  PYTHONPATH: /opencv-build/python_loader:$PYTHONPATH
+
+jobs:
+  BuildAndTest:
+    runs-on: opencv-cn-lin-arm64
+    defaults:
+      run:
+        shell: bash
+    container:
+      image: docker.io/yuentau/ocv_ubuntu:20.04-arm64
+    steps:
+    - name: PR info
+      run: |
+        echo "PR Author: ${{ env.PR_AUTHOR }}"
+        echo "PR Author fork: ${{ env.PR_AUTHOR_FORK }}"
+        echo "Source branch name: ${{ env.SOURCE_BRANCH_NAME }}"
+        echo "Target branch name: ${{ env.TARGET_BRANCH_NAME }}"
+    - name: Clean
+      run: find . -mindepth 1 -delete
+    - name: Fetch opencv
+      uses: actions/checkout@v3
+      with:
+        repository: opencv/opencv
+        ref: ${{ env.TARGET_BRANCH_NAME }}
+        fetch-depth: 0
+    - name: Merge opencv with ${{ env.SOURCE_BRANCH_NAME }} branch
+      run: |
+        cd ${{ env.OPENCV_DOCKER_WORKDIR }}
+        git config --global --add safe.directory ${{ env.OPENCV_DOCKER_WORKDIR }}
+        git config user.email "opencv.ci"
+        git config user.name "opencv.ci"
+        git pull -v "https://github.com/${{ env.PR_AUTHOR_FORK }}" "${{ env.SOURCE_BRANCH_NAME }}"
+    - name: Clone opencv_extra
+      run: git clone --single-branch --branch ${{ env.TARGET_BRANCH_NAME }} https://github.com/opencv/opencv_extra.git /opencv_extra
+    - name: Merge opencv_extra with ${{ env.SOURCE_BRANCH_NAME }} branch
+      run: |
+        OPENCV_EXTRA_FORK=$(git ls-remote --heads "https://github.com/${{ env.PR_AUTHOR }}/opencv_extra" "${{ env.SOURCE_BRANCH_NAME }}") || true
+        if [[ ! -z "$OPENCV_EXTRA_FORK" ]]; then
+          echo "Merge opencv_extra with ${{ env.SOURCE_BRANCH_NAME }} branch"
+          cd /opencv_extra
+          git config user.email "opencv.ci"
+          git config user.name "opencv.ci"
+          git pull -v "https://github.com/${{ env.PR_AUTHOR }}/opencv_extra" "${{ env.SOURCE_BRANCH_NAME }}"
+        else
+          echo "No merge since ${{ env.PR_AUTHOR }}/opencv_extra does not have branch ${{ env.SOURCE_BRANCH_NAME }}"
+        fi
+    - name: Configure OpenCV
+      run: |
+        cmake -G Ninja -B /opencv-build ${{ env.EXTRA_CMAKE_OPTIONS }} ${{ env.OPENCV_DOCKER_WORKDIR }}
+    - name: Build OpenCV
+      run: |
+        cd /opencv-build
+        ninja
+    - name: Accuracy:calib3d
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_calib3d
+    - name: Accuracy:core
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_core
+    - name: Accuracy:dnn
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_dnn
+    - name: Accuracy:features2d
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_features2d
+    - name: Accuracy:flann
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_flann
+    - name: Accuracy:highgui
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_highgui
+    - name: Accuracy:imgcodecs
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_imgcodecs
+    - name: Accuracy:imgproc
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_imgproc
+    - name: Accuracy:ml
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_ml
+    - name: Accuracy:objdetect
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_objdetect --gtest_filter="-Objdetect_QRCode_Close.regression/0:Objdetect_QRCode_Close.regression/4"
+    - name: Accuracy:photo
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_photo --gtest_filter="-Photo_CalibrateDebevec.regression"
+    - name: Accuracy:shape
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_shape
+    - name: Accuracy:stitching
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_stitching
+    - name: Accuracy:superres
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_superres
+    - name: Accuracy:video
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_video
+    - name: Accuracy:videoio
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_videoio
+    - name: Accuracy:videostab
+      run: cd /opencv-build && xvfb-run -a bin/opencv_test_videostab
+    - name: Performance:calib3d
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_calib3d --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1
+    - name: Performance:core
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_core --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1
+    - name: Performance:dnn
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_dnn --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1
+    - name: Performance:features2d
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_features2d --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1
+    - name: Performance:imgcodecs
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_imgcodecs --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1
+    - name: Performance:imgproc
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_imgproc --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1
+    - name: Performance:objdetect
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_objdetect --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1 --gtest_filter="-Perf_Objdetect_QRCode.detect/2:Perf_Objdetect_QRCode_Multi.decodeMulti*:Perf_Objdetect_QRCode_Multi.detectMulti*"
+    - name: Performance:photo
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_photo --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1
+    - name: Performance:stitching
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_stitching --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1
+    - name: Performance:superres
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_superres --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1
+    - name: Performance:video
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_video --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1
+    - name: Performance:videoio
+      run: cd /opencv-build && xvfb-run -a bin/opencv_perf_videoio --perf_impl=plain --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1
+    - name: Python3
+      run: |
+        cd ${{ env.OPENCV_DOCKER_WORKDIR }}/modules/python/test
+        python3 ./test.py --repo ../../../ -v
+    - name: Java
+      run: cd /opencv-build && xvfb-run -a python3 ${{ env.OPENCV_DOCKER_WORKDIR }}/modules/ts/misc/run.py . -a -t java
+    - name: Save Unit Test Results
+      uses: actions/upload-artifact@v3
+      if: always()
+      with:
+        name: junit-html
+        path: /opencv-build/java_test/testResults/junit-noframes.html
+
+  BuildContrib:
+    runs-on: opencv-cn-lin-arm64
+    defaults:
+      run:
+        shell: bash
+    container:
+      image: docker.io/yuentau/ocv_ubuntu:20.04-arm64
+    steps:
+    - name: PR info
+      run: |
+        echo "PR Author: ${{ env.PR_AUTHOR }}"
+        echo "Source branch name: ${{ env.SOURCE_BRANCH_NAME }}"
+        echo "Target branch name: ${{ env.TARGET_BRANCH_NAME }}"
+    - name: Clean
+      run: find . -mindepth 1 -delete
+    - name: Fetch opencv
+      uses: actions/checkout@v3
+      with:
+        repository: opencv/opencv
+        ref: ${{ env.TARGET_BRANCH_NAME }}
+        fetch-depth: 0
+    - name: Merge opencv with a test branch
+      run: |
+        cd ${{ env.OPENCV_DOCKER_WORKDIR }}
+        git config --global --add safe.directory ${{ env.OPENCV_DOCKER_WORKDIR }}
+        git config user.email "opencv.ci"
+        git config user.name "opencv.ci"
+        git pull -v "https://github.com/${{ env.PR_AUTHOR_FORK }}" "${{ env.SOURCE_BRANCH_NAME }}"
+    - name: Clone opencv_contrib
+      run: git clone --single-branch --branch ${{ env.TARGET_BRANCH_NAME }} https://github.com/opencv/opencv_contrib.git /opencv_contrib
+    - name: Merge opencv_contrib with ${{ env.SOURCE_BRANCH_NAME }} branch
+      run: |
+        OPENCV_CONTRIB_FORK=$(git ls-remote --heads "https://github.com/${{ env.PR_AUTHOR }}/opencv_contrib" "${{ env.SOURCE_BRANCH_NAME }}") || true
+        if [[ ! -z "$OPENCV_CONTRIB_FORK" ]]; then
+          echo "Merge opencv_contrib with ${{ env.SOURCE_BRANCH_NAME }} branch"
+          cd /opencv_contrib
+          git config user.email "opencv.ci"
+          git config user.name "opencv.ci"
+          git pull -v "https://github.com/${{ env.PR_AUTHOR }}/opencv_contrib" "${{ env.SOURCE_BRANCH_NAME }}"
+        else
+          echo "No merge since ${{ env.PR_AUTHOR }}/opencv_contrib does not have branch ${{ env.SOURCE_BRANCH_NAME }}"
+        fi
+    - name: Configure OpenCV Contrib
+      run: |
+        cmake -G Ninja -B /opencv-contrib-build ${{ env.EXTRA_CMAKE_OPTIONS }} -DOPENCV_EXTRA_MODULES_PATH=/opencv_contrib/modules ${{ env.OPENCV_DOCKER_WORKDIR }}
+    - name: Build OpenCV Contrib
+      run: |
+        cd /opencv-contrib-build
+        ninja
diff --git a/.github/workflows/PR-4.x-U20.yaml b/.github/workflows/PR-4.x-U20.yaml
index 5fd17b623e..10b0847bab 100644
--- a/.github/workflows/PR-4.x-U20.yaml
+++ b/.github/workflows/PR-4.x-U20.yaml
@@ -6,24 +6,29 @@ on:
       - 4.x
 
 env:
-  EXTRA_CMAKE_OPTIONS: '-DBUILD_DOCS=ON -DPYTHON_DEFAULT_EXECUTABLE=/usr/bin/python3 -DBUILD_EXAMPLES=ON -DOPENCV_ENABLE_NONFREE=ON -DENABLE_CCACHE=OFF'
-  OPENCV_TEST_DATA_PATH: '/opencv_extra/testdata'
-  OPENCV_DOCKER_WORKDIR: '/__w/opencv/opencv'
+  EXTRA_CMAKE_OPTIONS: '-DBUILD_DOCS=ON -DPYTHON_DEFAULT_EXECUTABLE=/usr/bin/python3 -DOPENCV_DOWNLOAD_PATH=/home/ci/binaries_cache -DBUILD_EXAMPLES=ON -DOPENCV_ENABLE_NONFREE=ON'
   PR_AUTHOR: ${{ github.event.pull_request.user.login }}
   PR_AUTHOR_FORK: ${{ github.event.pull_request.head.repo.full_name }}
   SOURCE_BRANCH_NAME: ${{ github.head_ref }}
   TARGET_BRANCH_NAME: ${{ github.base_ref }}
-  ANT_HOME: '/usr/share/ant'
+  ANT_HOME: /usr/share/ant
+  GIT_CACHE_DOCKER: /home/ci/git_cache
   PYTHONPATH: /opencv-build/python_loader:$PYTHONPATH
+  OPENCV_TEST_DATA_PATH: /opencv_extra/testdata
+  OPENCV_DOCKER_WORKDIR: /opencv
 
 jobs:
   BuildAndTest:
-    runs-on: ubuntu-20.04
+    runs-on: opencv-cn-lin-x86-64
     defaults:
       run:
         shell: bash
     container:
       image: quay.io/asenyaev/opencv-ubuntu:20.04
+      volumes:
+        - /home/opencv-cn/git_cache:/home/ci/git_cache
+        - /home/opencv-cn/ci_cache/opencv:/home/ci/.ccache
+        - /home/opencv-cn/binaries_cache:/home/ci/binaries_cache
     steps:
     - name: PR info
       run: |
@@ -31,13 +36,9 @@ jobs:
         echo "Source branch name: ${{ env.SOURCE_BRANCH_NAME }}"
         echo "Target branch name: ${{ env.TARGET_BRANCH_NAME }}"
     - name: Clean
-      run: find . -mindepth 1 -delete
+      run: find ${{ env.OPENCV_DOCKER_WORKDIR }} -mindepth 1 -delete
     - name: Fetch opencv
-      uses: actions/checkout@v3
-      with:
-        repository: opencv/opencv
-        ref: ${{ env.TARGET_BRANCH_NAME }}
-        fetch-depth: 0
+      run: git clone --branch ${{ env.TARGET_BRANCH_NAME }} --reference ${{ env.GIT_CACHE_DOCKER }}/opencv.git https://github.com/opencv/opencv.git ${{ env.OPENCV_DOCKER_WORKDIR }}
     - name: Merge opencv with ${{ env.SOURCE_BRANCH_NAME }} branch
       run: |
         cd ${{ env.OPENCV_DOCKER_WORKDIR }}
@@ -46,7 +47,7 @@ jobs:
         git config user.name "opencv.ci"
         git pull -v "https://github.com/${{ env.PR_AUTHOR_FORK }}" "${{ env.SOURCE_BRANCH_NAME }}"
     - name: Clone opencv_extra
-      run: git clone --single-branch --branch ${{ env.TARGET_BRANCH_NAME }} https://github.com/opencv/opencv_extra.git /opencv_extra
+      run: git clone --single-branch --branch ${{ env.TARGET_BRANCH_NAME }} --reference ${{ env.GIT_CACHE_DOCKER }}/opencv_extra.git https://github.com/opencv/opencv_extra.git /opencv_extra
     - name: Merge opencv_extra with ${{ env.SOURCE_BRANCH_NAME }} branch
       run: |
         OPENCV_EXTRA_FORK=$(git ls-remote --heads "https://github.com/${{ env.PR_AUTHOR }}/opencv_extra" "${{ env.SOURCE_BRANCH_NAME }}") || true
@@ -137,12 +138,16 @@ jobs:
       run: cd /opencv-build && cmake --build . --config release --target check_pylint -- -j4
 
   BuildContrib:
-    runs-on: ubuntu-20.04
+    runs-on: opencv-cn-lin-x86-64
     defaults:
       run:
         shell: bash
     container:
       image: quay.io/asenyaev/opencv-ubuntu:20.04
+      volumes:
+        - /home/opencv-cn/git_cache:/home/ci/git_cache
+        - /home/opencv-cn/ci_cache/opencv:/home/ci/.ccache
+        - /home/opencv-cn/binaries_cache:/home/ci/binaries_cache
     steps:
     - name: PR info
       run: |
@@ -150,13 +155,9 @@ jobs:
         echo "Source branch name: ${{ env.SOURCE_BRANCH_NAME }}"
         echo "Target branch name: ${{ env.TARGET_BRANCH_NAME }}"
     - name: Clean
-      run: find . -mindepth 1 -delete
+      run: find ${{ env.OPENCV_DOCKER_WORKDIR }} -mindepth 1 -delete
     - name: Fetch opencv
-      uses: actions/checkout@v3
-      with:
-        repository: opencv/opencv
-        ref: ${{ env.TARGET_BRANCH_NAME }}
-        fetch-depth: 0
+      run: git clone --branch ${{ env.TARGET_BRANCH_NAME }} --reference ${{ env.GIT_CACHE_DOCKER }}/opencv.git https://github.com/opencv/opencv.git ${{ env.OPENCV_DOCKER_WORKDIR }}
     - name: Merge opencv with a test branch
       run: |
         cd ${{ env.OPENCV_DOCKER_WORKDIR }}
diff --git a/.github/workflows/PR-4.x-W10.yaml b/.github/workflows/PR-4.x-W10.yaml
index 0e313f32e5..8ebd8c782e 100644
--- a/.github/workflows/PR-4.x-W10.yaml
+++ b/.github/workflows/PR-4.x-W10.yaml
@@ -6,14 +6,13 @@ on:
       - 4.x
 
 env:
-  EXTRA_CMAKE_OPTIONS: '-DCL_Z_OPTION=/Z7 -DOPENCV_DOWNLOAD_PATH=c:\Slave\workspace\binaries_cache -DBUILD_EXAMPLES=ON -DOPENCV_ENABLE_NONFREE=ON -DCMAKE_BUILD_TYPE=Release'
+  EXTRA_CMAKE_OPTIONS: '-DCL_Z_OPTION=/Z7 -DOPENCV_DOWNLOAD_PATH=%BINARIES_CACHE% -DBUILD_EXAMPLES=ON -DOPENCV_ENABLE_NONFREE=ON -DCMAKE_BUILD_TYPE=Release'
   OPENCV_TEST_DATA_PATH: ${{ github.workspace }}\opencv_extra\testdata
   PR_AUTHOR: ${{ github.event.pull_request.user.login }}
   PR_AUTHOR_FORK: ${{ github.event.pull_request.head.repo.full_name }}
   SOURCE_BRANCH_NAME: ${{ github.head_ref }}
   TARGET_BRANCH_NAME: ${{ github.base_ref }}
   GTEST_FILTER_STRING: '-Samples.findFile:videoio/videocapture_acceleration.read/122:videoio/videocapture_acceleration.read/126'
-  GIT_CACHE: c:\Slave\git_cache
 
 jobs:
   BuildAndTest:
@@ -30,25 +29,25 @@ jobs:
     - name: Clean
       run: cd ${{ github.workspace }} && rm -rf *
     - name: Fetch opencv
-      run: cd ${{ github.workspace }} && git clone --branch ${{ env.TARGET_BRANCH_NAME }} --reference ${{ env.GIT_CACHE }}\opencv.git https://github.com/opencv/opencv.git
+      run: cd ${{ github.workspace }} && git clone --branch ${{ env.TARGET_BRANCH_NAME }} --reference %GIT_CACHE%\opencv.git git@github.com:opencv/opencv.git
     - name: Merge opencv with ${{ env.SOURCE_BRANCH_NAME }} branch
       run: |
         cd ${{ github.workspace }}\opencv
         git config user.email "opencv.ci"
         git config user.name "opencv.ci"
-        git pull -v "https://github.com/${{ env.PR_AUTHOR_FORK }}" "${{ env.SOURCE_BRANCH_NAME }}"
+        git pull -v "git@github.com:${{ env.PR_AUTHOR_FORK }}" "${{ env.SOURCE_BRANCH_NAME }}"
     - name: Fetch opencv_extra
-      run: cd ${{ github.workspace }} && git clone --single-branch --branch ${{ env.TARGET_BRANCH_NAME }} --reference ${{ env.GIT_CACHE }}\opencv_extra.git https://github.com/opencv/opencv_extra.git
+      run: cd ${{ github.workspace }} && git clone --single-branch --branch ${{ env.TARGET_BRANCH_NAME }} --reference %GIT_CACHE%\opencv_extra.git git@github.com:opencv/opencv_extra.git
     - name: Merge opencv_extra with ${{ env.SOURCE_BRANCH_NAME }} branch
       shell: bash
       run: |
-        RET=$(git ls-remote --heads "https://github.com/${{ env.PR_AUTHOR }}/opencv_extra" "${{ env.SOURCE_BRANCH_NAME }}") || true
-        if [[ ! -z "$RET" ]]; then
+        OPENCV_EXTRA_FORK=$(git ls-remote --heads "git@github.com:/${{ env.PR_AUTHOR }}/opencv_extra" "${{ env.SOURCE_BRANCH_NAME }}") || true
+        if [[ ! -z "$OPENCV_EXTRA_FORK" ]]; then
           echo "Merge opencv_extra with ${{ env.SOURCE_BRANCH_NAME }} branch"
           cd opencv_extra
           git config user.email "opencv.ci"
           git config user.name "opencv.ci"
-          git pull -v "https://github.com/${{ env.PR_AUTHOR }}/opencv_extra" "${{ env.SOURCE_BRANCH_NAME }}"
+          git pull -v "git@github.com:${{ env.PR_AUTHOR }}/opencv_extra" "${{ env.SOURCE_BRANCH_NAME }}"
         else
           echo "No merge since ${{ env.PR_AUTHOR }}/opencv_extra does not have branch ${{ env.SOURCE_BRANCH_NAME }}"
         fi
@@ -143,15 +142,28 @@ jobs:
     - name: Clean
       run: cd ${{ github.workspace }} && rm -rf *
     - name: Fetch opencv
-      run: cd ${{ github.workspace }} && git clone --branch ${{ env.TARGET_BRANCH_NAME }} --reference ${{ env.GIT_CACHE }}\opencv.git https://github.com/opencv/opencv.git
+      run: cd ${{ github.workspace }} && git clone --branch ${{ env.TARGET_BRANCH_NAME }} --reference %GIT_CACHE%\opencv.git git@github.com:opencv/opencv.git
     - name: Merge opencv with ${{ env.SOURCE_BRANCH_NAME }} branch
       run: |
         cd ${{ github.workspace }}\opencv
         git config user.email "opencv.ci"
         git config user.name "opencv.ci"
-        git pull -v "https://github.com/${{ env.PR_AUTHOR_FORK }}" "${{ env.SOURCE_BRANCH_NAME }}"
+        git pull -v "git@github.com:${{ env.PR_AUTHOR_FORK }}" "${{ env.SOURCE_BRANCH_NAME }}"
     - name: Fetch opencv_contrib
-      run: cd ${{ github.workspace }} && git clone --single-branch --branch ${{ env.TARGET_BRANCH_NAME }} --reference ${{ env.GIT_CACHE }}\opencv_contrib.git --depth 1 https://github.com/opencv/opencv_contrib.git
+      run: cd ${{ github.workspace }} && git clone --single-branch --branch ${{ env.TARGET_BRANCH_NAME }} --reference %GIT_CACHE%\opencv_contrib.git --depth 1 git@github.com:opencv/opencv_contrib.git
+    - name: Merge opencv_contrib with ${{ env.SOURCE_BRANCH_NAME }} branch
+      shell: bash
+      run: |
+        OPENCV_CONTRIB_FORK=$(git ls-remote --heads "git@github.com:${{ env.PR_AUTHOR }}/opencv_contrib" "${{ env.SOURCE_BRANCH_NAME }}") || true
+        if [[ ! -z "$OPENCV_CONTRIB_FORK" ]]; then
+          echo "Merge opencv_contrib with ${{ env.SOURCE_BRANCH_NAME }} branch"
+          cd /opencv_contrib
+          git config user.email "opencv.ci"
+          git config user.name "opencv.ci"
+          git pull -v "git@github.com:${{ env.PR_AUTHOR }}/opencv_contrib" "${{ env.SOURCE_BRANCH_NAME }}"
+        else
+          echo "No merge since ${{ env.PR_AUTHOR }}/opencv_contrib does not have branch ${{ env.SOURCE_BRANCH_NAME }}"
+        fi
     - name: Configure OpenCV Contrib
       run: |
         mkdir ${{ github.workspace }}\opencv-contrib-build && cd ${{ github.workspace }}\opencv-contrib-build
diff --git a/3rdparty/openvx/README.md b/3rdparty/openvx/README.md
index 2f869a42bf..339b5072cc 100644
--- a/3rdparty/openvx/README.md
+++ b/3rdparty/openvx/README.md
@@ -77,7 +77,7 @@ E.g. external ref-counting is implemented for 1.0 version and native OpenVX one
 
 Also there are some **C++ 11** features are used (e.g. rvalue ref-s) when their availability is detected at ***compile time***.
 
-C++ exceptions are used for errors indication instead of return codes. There are two types of exceptions are defined:  `RuntimeError` is thrown when OpenVX C call returned unsuccessful result and `WrapperError` is thrown when a problem is occured in the wrappers code. Both exception calsses are derived from `std::exception` (actually from its inheritants).
+C++ exceptions are used for errors indication instead of return codes. There are two types of exceptions are defined:  `RuntimeError` is thrown when OpenVX C call returned unsuccessful result and `WrapperError` is thrown when a problem is occurred in the wrappers code. Both exception calsses are derived from `std::exception` (actually from its inheritants).
 
 The so called **OpenVX objects** (e.g. `vx_image`) are represented as C++ classes in wrappers.
 All these classes use automatic ref-counting that allows development of exception-safe code.
diff --git a/doc/js_tutorials/js_imgproc/js_morphological_ops/js_morphological_ops.markdown b/doc/js_tutorials/js_imgproc/js_morphological_ops/js_morphological_ops.markdown
index b5e10e0e67..9ffa218bb2 100644
--- a/doc/js_tutorials/js_imgproc/js_morphological_ops/js_morphological_ops.markdown
+++ b/doc/js_tutorials/js_imgproc/js_morphological_ops/js_morphological_ops.markdown
@@ -52,7 +52,7 @@ Try it
 
 ### 2. Dilation
 
-It is just opposite of erosion. Here, a pixel element is '1' if atleast one pixel under the kernel
+It is just opposite of erosion. Here, a pixel element is '1' if at least one pixel under the kernel
 is '1'. So it increases the white region in the image or size of foreground object increases.
 Normally, in cases like noise removal, erosion is followed by dilation. Because, erosion removes
 white noises, but it also shrinks our object. So we dilate it. Since noise is gone, they won't come
diff --git a/doc/js_tutorials/js_setup/js_nodejs/js_nodejs.markdown b/doc/js_tutorials/js_setup/js_nodejs/js_nodejs.markdown
index 361543502b..f424d0ca81 100644
--- a/doc/js_tutorials/js_setup/js_nodejs/js_nodejs.markdown
+++ b/doc/js_tutorials/js_setup/js_nodejs/js_nodejs.markdown
@@ -223,7 +223,7 @@ Before the example, is worth consider first how files are handled in emscripten
 
 These C++ sources use standard APIs to access the filesystem and the implementation often ends up in system calls that read a file in the hard drive. Since JavaScript applications in the browser don't have access to the local filesystem, [emscripten emulates a standard filesystem](https://emscripten.org/docs/api_reference/Filesystem-API.html) so compiled C++ code works out of the box.
 
-In the browser, this filesystem is emulated in memory while in Node.js there's also the possibility of using the local filesystem directly. This is often preferable since there's no need of copy file's content in memory. This section is explains how to do do just that, this is, configuring emscripten so files are accessed directly from our local filesystem and relative paths match files relative to the current local directory as expected.
+In the browser, this filesystem is emulated in memory while in Node.js there's also the possibility of using the local filesystem directly. This is often preferable since there's no need of copy file's content in memory. This section explains how to do just that, this is, configuring emscripten so files are accessed directly from our local filesystem and relative paths match files relative to the current local directory as expected.
 
 ### The example ###
 
diff --git a/doc/py_tutorials/py_feature2d/py_feature_homography/py_feature_homography.markdown b/doc/py_tutorials/py_feature2d/py_feature_homography/py_feature_homography.markdown
index f8836b095b..6abac2c57b 100644
--- a/doc/py_tutorials/py_feature2d/py_feature_homography/py_feature_homography.markdown
+++ b/doc/py_tutorials/py_feature2d/py_feature_homography/py_feature_homography.markdown
@@ -18,7 +18,7 @@ is sufficient to find the object exactly on the trainImage.
 
 For that, we can use a function from calib3d module, ie **cv.findHomography()**. If we pass the set
 of points from both the images, it will find the perspective transformation of that object. Then we
-can use **cv.perspectiveTransform()** to find the object. It needs atleast four correct points to
+can use **cv.perspectiveTransform()** to find the object. It needs at least four correct points to
 find the transformation.
 
 We have seen that there can be some possible errors while matching which may affect the result. To
@@ -64,7 +64,7 @@ for m,n in matches:
     if m.distance < 0.7*n.distance:
         good.append(m)
 @endcode
-Now we set a condition that atleast 10 matches (defined by MIN_MATCH_COUNT) are to be there to
+Now we set a condition that at least 10 matches (defined by MIN_MATCH_COUNT) are to be there to
 find the object. Otherwise simply show a message saying not enough matches are present.
 
 If enough matches are found, we extract the locations of matched keypoints in both the images. They
diff --git a/doc/py_tutorials/py_imgproc/py_morphological_ops/py_morphological_ops.markdown b/doc/py_tutorials/py_imgproc/py_morphological_ops/py_morphological_ops.markdown
index 35e716d8e9..84a62d14cd 100644
--- a/doc/py_tutorials/py_imgproc/py_morphological_ops/py_morphological_ops.markdown
+++ b/doc/py_tutorials/py_imgproc/py_morphological_ops/py_morphological_ops.markdown
@@ -48,7 +48,7 @@ Result:
 
 ### 2. Dilation
 
-It is just opposite of erosion. Here, a pixel element is '1' if atleast one pixel under the kernel
+It is just opposite of erosion. Here, a pixel element is '1' if at least one pixel under the kernel
 is '1'. So it increases the white region in the image or size of foreground object increases.
 Normally, in cases like noise removal, erosion is followed by dilation. Because, erosion removes
 white noises, but it also shrinks our object. So we dilate it. Since noise is gone, they won't come
diff --git a/doc/tutorials/imgproc/imgtrans/hough_circle/hough_circle.markdown b/doc/tutorials/imgproc/imgtrans/hough_circle/hough_circle.markdown
index 952b54249d..937e291342 100644
--- a/doc/tutorials/imgproc/imgtrans/hough_circle/hough_circle.markdown
+++ b/doc/tutorials/imgproc/imgtrans/hough_circle/hough_circle.markdown
@@ -81,11 +81,11 @@ The image we used can be found [here](https://raw.githubusercontent.com/opencv/o
 @end_toggle
 
 @add_toggle_java
-@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py load
+@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java load
 @end_toggle
 
 @add_toggle_python
-@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java load
+@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py load
 @end_toggle
 
 ####  Convert it to grayscale:
@@ -95,11 +95,11 @@ The image we used can be found [here](https://raw.githubusercontent.com/opencv/o
 @end_toggle
 
 @add_toggle_java
-@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py convert_to_gray
+@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java convert_to_gray
 @end_toggle
 
 @add_toggle_python
-@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java convert_to_gray
+@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py convert_to_gray
 @end_toggle
 
 #### Apply a Median blur to reduce noise and avoid false circle detection:
@@ -109,11 +109,11 @@ The image we used can be found [here](https://raw.githubusercontent.com/opencv/o
 @end_toggle
 
 @add_toggle_java
-@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py reduce_noise
+@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java reduce_noise
 @end_toggle
 
 @add_toggle_python
-@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java reduce_noise
+@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py reduce_noise
 @end_toggle
 
 #### Proceed to apply Hough Circle Transform:
@@ -123,11 +123,11 @@ The image we used can be found [here](https://raw.githubusercontent.com/opencv/o
 @end_toggle
 
 @add_toggle_java
-@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py houghcircles
+@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java houghcircles
 @end_toggle
 
 @add_toggle_python
-@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java houghcircles
+@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py houghcircles
 @end_toggle
 
 -   with the arguments:
@@ -151,11 +151,11 @@ The image we used can be found [here](https://raw.githubusercontent.com/opencv/o
 @end_toggle
 
 @add_toggle_java
-@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py draw
+@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java draw
 @end_toggle
 
 @add_toggle_python
-@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java draw
+@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py draw
 @end_toggle
 
 You can see that we will draw the circle(s) on red and the center(s) with a small green dot
@@ -167,11 +167,11 @@ You can see that we will draw the circle(s) on red and the center(s) with a smal
 @end_toggle
 
 @add_toggle_java
-@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py display
+@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java display
 @end_toggle
 
 @add_toggle_python
-@snippet samples/java/tutorial_code/ImgTrans/HoughCircle/HoughCircles.java display
+@snippet samples/python/tutorial_code/ImgTrans/HoughCircle/hough_circle.py display
 @end_toggle
 
 Result
diff --git a/doc/tutorials/imgproc/morph_lines_detection/morph_lines_detection.md b/doc/tutorials/imgproc/morph_lines_detection/morph_lines_detection.md
index ce5223c521..2d0f5de98d 100644
--- a/doc/tutorials/imgproc/morph_lines_detection/morph_lines_detection.md
+++ b/doc/tutorials/imgproc/morph_lines_detection/morph_lines_detection.md
@@ -130,7 +130,7 @@ Get image from [here](https://raw.githubusercontent.com/opencv/opencv/4.x/doc/tu
 
 #### Output images
 
-Now we are ready to apply morphological operations in order to extract the horizontal and vertical lines and as a consequence to separate the the music notes from the music sheet, but first let's initialize the output images that we will use for that reason:
+Now we are ready to apply morphological operations in order to extract the horizontal and vertical lines and as a consequence to separate the music notes from the music sheet, but first let's initialize the output images that we will use for that reason:
 
 @add_toggle_cpp
 @snippet samples/cpp/tutorial_code/ImgProc/morph_lines_detection/Morphology_3.cpp init
diff --git a/modules/core/include/opencv2/core/mat.hpp b/modules/core/include/opencv2/core/mat.hpp
index b6985c7831..2aba15c4b9 100644
--- a/modules/core/include/opencv2/core/mat.hpp
+++ b/modules/core/include/opencv2/core/mat.hpp
@@ -1018,7 +1018,7 @@ public:
     @param copyData Flag to specify whether the underlying data of the STL vector should be copied
     to (true) or shared with (false) the newly constructed matrix. When the data is copied, the
     allocated buffer is managed using Mat reference counting mechanism. While the data is shared,
-    the reference counter is NULL, and you should not deallocate the data until the matrix is not
+    the reference counter is NULL, and you should not deallocate the data until the matrix is
     destructed.
     */
     template<typename _Tp> explicit Mat(const std::vector<_Tp>& vec, bool copyData=false);
@@ -2276,7 +2276,7 @@ public:
     std::reverse_iterator<const_iterator> rbegin() const;
     std::reverse_iterator<const_iterator> rend() const;
 
-    //! template methods for for operation over all matrix elements.
+    //! template methods for operation over all matrix elements.
     // the operations take care of skipping gaps in the end of rows (if any)
     template<typename Functor> void forEach(const Functor& operation);
     template<typename Functor> void forEach(const Functor& operation) const;
diff --git a/modules/core/src/parallel.cpp b/modules/core/src/parallel.cpp
index 763b8a8d6d..26e5e8c19b 100644
--- a/modules/core/src/parallel.cpp
+++ b/modules/core/src/parallel.cpp
@@ -986,7 +986,7 @@ int getNumberOfCPUs_()
 
 #endif
 
-#if !defined(_WIN32) && !defined(__APPLE__)
+#if !defined(_WIN32) && !defined(__APPLE__) && defined(_SC_NPROCESSORS_ONLN)
 
     static unsigned cpu_count_sysconf = (unsigned)sysconf( _SC_NPROCESSORS_ONLN );
     ncpus = minNonZero(ncpus, cpu_count_sysconf);
diff --git a/modules/dnn/src/onnx/opencv-onnx.proto b/modules/dnn/src/onnx/opencv-onnx.proto
index b24220adb9..8dd69cb2d9 100644
--- a/modules/dnn/src/onnx/opencv-onnx.proto
+++ b/modules/dnn/src/onnx/opencv-onnx.proto
@@ -61,7 +61,7 @@ enum Version {
   // The version field is always serialized and we will use it to store the
   // version that the  graph is generated from. This helps us set up version
   // control.
-  // For the IR, we are using simple numbers starting with with 0x00000001,
+  // For the IR, we are using simple numbers starting with 0x00000001,
   // which was the version we published on Oct 10, 2017.
   IR_VERSION_2017_10_10 = 0x0000000000000001;
 
diff --git a/modules/imgcodecs/include/opencv2/imgcodecs.hpp b/modules/imgcodecs/include/opencv2/imgcodecs.hpp
index 5732532ca9..c70ef6313d 100644
--- a/modules/imgcodecs/include/opencv2/imgcodecs.hpp
+++ b/modules/imgcodecs/include/opencv2/imgcodecs.hpp
@@ -301,7 +301,7 @@ CV_EXPORTS Mat imdecode( InputArray buf, int flags, Mat* dst);
 The function imencode compresses the image and stores it in the memory buffer that is resized to fit the
 result. See cv::imwrite for the list of supported formats and flags description.
 
-@param ext File extension that defines the output format.
+@param ext File extension that defines the output format. Must include a leading period.
 @param img Image to be written.
 @param buf Output buffer resized to fit the compressed image.
 @param params Format-specific parameters. See cv::imwrite and cv::ImwriteFlags.
diff --git a/modules/imgcodecs/src/grfmt_jpeg.cpp b/modules/imgcodecs/src/grfmt_jpeg.cpp
index 17feafc404..b200c35a31 100644
--- a/modules/imgcodecs/src/grfmt_jpeg.cpp
+++ b/modules/imgcodecs/src/grfmt_jpeg.cpp
@@ -602,9 +602,9 @@ bool JpegEncoder::write( const Mat& img, const std::vector<int>& params )
     JpegErrorMgr jerr;
     JpegDestination dest;
 
-    jpeg_create_compress(&cinfo);
     cinfo.err = jpeg_std_error(&jerr.pub);
     jerr.pub.error_exit = error_exit;
+    jpeg_create_compress(&cinfo);
 
     if( !m_buf )
     {
diff --git a/modules/imgcodecs/src/grfmt_tiff.cpp b/modules/imgcodecs/src/grfmt_tiff.cpp
index 2941284e84..a2b55ea2ff 100644
--- a/modules/imgcodecs/src/grfmt_tiff.cpp
+++ b/modules/imgcodecs/src/grfmt_tiff.cpp
@@ -1121,7 +1121,7 @@ bool TiffEncoder::writeLibTiff( const std::vector<Mat>& img_vec, const std::vect
 
         CV_TIFF_CHECK_CALL(TIFFSetField(tif, TIFFTAG_SAMPLEFORMAT, sample_format));
 
-        if (page_compression != COMPRESSION_NONE)
+        if (page_compression == COMPRESSION_LZW || page_compression == COMPRESSION_ADOBE_DEFLATE || page_compression == COMPRESSION_DEFLATE)
         {
             CV_TIFF_CHECK_CALL(TIFFSetField(tif, TIFFTAG_PREDICTOR, predictor));
         }
diff --git a/modules/imgcodecs/test/test_tiff.cpp b/modules/imgcodecs/test/test_tiff.cpp
index 28e084d5b0..b7b6b95d83 100644
--- a/modules/imgcodecs/test/test_tiff.cpp
+++ b/modules/imgcodecs/test/test_tiff.cpp
@@ -359,6 +359,49 @@ TEST(Imgcodecs_Tiff, read_palette_color_image)
     ASSERT_EQ(CV_8UC3, img.type());
 }
 
+TEST(Imgcodecs_Tiff, readWrite_predictor)
+{
+    /* see issue #21871
+     */
+    const uchar sample_data[160] = {
+        0xff, 0xff, 0xff, 0xff, 0x88, 0x88, 0xff, 0xff, 0x88, 0x88, 0xff, 0xff, 0xff, 0xff, 0xff, 0x88,
+        0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00,
+        0xff, 0x00, 0x00, 0x44, 0xff, 0xff, 0x88, 0xff, 0x33, 0x00, 0x66, 0xff, 0xff, 0x88, 0x00, 0x44,
+        0x88, 0x00, 0x44, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x44, 0xff, 0xff, 0x11, 0x00, 0xff,
+        0x11, 0x00, 0x88, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff,
+        0x11, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x33, 0x00, 0x88, 0xff, 0x00, 0x66, 0xff,
+        0x11, 0x00, 0x66, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x44, 0x33, 0x00, 0xff, 0xff,
+        0x88, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
+        0xff, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0x33, 0x00, 0x00, 0x66, 0xff, 0xff,
+        0xff, 0xff, 0x88, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff
+    };
+
+    cv::Mat mat(10, 16, CV_8UC1, (void*)sample_data);
+    int methods[] = {
+        COMPRESSION_NONE,     COMPRESSION_LZW,
+        COMPRESSION_PACKBITS, COMPRESSION_DEFLATE,  COMPRESSION_ADOBE_DEFLATE
+    };
+    for (size_t i = 0; i < sizeof(methods) / sizeof(int); i++)
+    {
+        string out = cv::tempfile(".tif");
+
+        std::vector<int> params;
+        params.push_back(TIFFTAG_COMPRESSION);
+        params.push_back(methods[i]);
+        params.push_back(TIFFTAG_PREDICTOR);
+        params.push_back(PREDICTOR_HORIZONTAL);
+
+        EXPECT_NO_THROW(cv::imwrite(out, mat, params));
+
+        const Mat img = cv::imread(out, IMREAD_UNCHANGED);
+        ASSERT_FALSE(img.empty());
+
+        ASSERT_EQ(0, cv::norm(mat, img, cv::NORM_INF));
+
+        EXPECT_EQ(0, remove(out.c_str()));
+    }
+}
+
 
 //==================================================================================================
 
diff --git a/modules/imgproc/include/opencv2/imgproc.hpp b/modules/imgproc/include/opencv2/imgproc.hpp
index 2f5423643b..3e0180ab6a 100644
--- a/modules/imgproc/include/opencv2/imgproc.hpp
+++ b/modules/imgproc/include/opencv2/imgproc.hpp
@@ -118,7 +118,7 @@ sophisticated [interpolation methods](http://en.wikipedia.org/wiki/Multivariate_
 where a polynomial function is fit into some neighborhood of the computed pixel \f$(f_x(x,y),
 f_y(x,y))\f$, and then the value of the polynomial at \f$(f_x(x,y), f_y(x,y))\f$ is taken as the
 interpolated pixel value. In OpenCV, you can choose between several interpolation methods. See
-resize for details.
+#resize for details.
 
 @note The geometrical transformations do not work with `CV_8S` or `CV_32S` images.
 
@@ -1576,7 +1576,7 @@ CV_EXPORTS_W void boxFilter( InputArray src, OutputArray dst, int ddepth,
 For every pixel \f$ (x, y) \f$ in the source image, the function calculates the sum of squares of those neighboring
 pixel values which overlap the filter placed over the pixel \f$ (x, y) \f$.
 
-The unnormalized square box filter can be useful in computing local image statistics such as the the local
+The unnormalized square box filter can be useful in computing local image statistics such as the local
 variance and standard deviation around the neighborhood of a pixel.
 
 @param src input image
@@ -2345,7 +2345,7 @@ way:
     resize(src, dst, Size(), 0.5, 0.5, interpolation);
 @endcode
 To shrink an image, it will generally look best with #INTER_AREA interpolation, whereas to
-enlarge an image, it will generally look best with c#INTER_CUBIC (slow) or #INTER_LINEAR
+enlarge an image, it will generally look best with #INTER_CUBIC (slow) or #INTER_LINEAR
 (faster but still looks OK).
 
 @param src input image.
@@ -2437,7 +2437,7 @@ The function remap transforms the source image using the specified map:
 where values of pixels with non-integer coordinates are computed using one of available
 interpolation methods. \f$map_x\f$ and \f$map_y\f$ can be encoded as separate floating-point maps
 in \f$map_1\f$ and \f$map_2\f$ respectively, or interleaved floating-point maps of \f$(x,y)\f$ in
-\f$map_1\f$, or fixed-point maps created by using convertMaps. The reason you might want to
+\f$map_1\f$, or fixed-point maps created by using #convertMaps. The reason you might want to
 convert from floating to fixed-point representations of a map is that they can yield much faster
 (\~2x) remapping operations. In the converted case, \f$map_1\f$ contains pairs (cvFloor(x),
 cvFloor(y)) and \f$map_2\f$ contains indices in a table of interpolation coefficients.
@@ -2447,7 +2447,7 @@ This function cannot operate in-place.
 @param src Source image.
 @param dst Destination image. It has the same size as map1 and the same type as src .
 @param map1 The first map of either (x,y) points or just x values having the type CV_16SC2 ,
-CV_32FC1, or CV_32FC2. See convertMaps for details on converting a floating point
+CV_32FC1, or CV_32FC2. See #convertMaps for details on converting a floating point
 representation to fixed-point for speed.
 @param map2 The second map of y values having the type CV_16UC1, CV_32FC1, or none (empty map
 if map1 is (x,y) points), respectively.
@@ -2472,7 +2472,7 @@ options ( (map1.type(), map2.type()) \f$\rightarrow\f$ (dstmap1.type(), dstmap2.
 supported:
 
 - \f$\texttt{(CV_32FC1, CV_32FC1)} \rightarrow \texttt{(CV_16SC2, CV_16UC1)}\f$. This is the
-most frequently used conversion operation, in which the original floating-point maps (see remap )
+most frequently used conversion operation, in which the original floating-point maps (see #remap)
 are converted to a more compact and much faster fixed-point representation. The first output array
 contains the rounded coordinates and the second array (created only when nninterpolation=false )
 contains indices in the interpolation tables.
diff --git a/modules/imgproc/src/opencl/medianFilter.cl b/modules/imgproc/src/opencl/medianFilter.cl
index f9a6c9e8f4..b517a38059 100644
--- a/modules/imgproc/src/opencl/medianFilter.cl
+++ b/modules/imgproc/src/opencl/medianFilter.cl
@@ -43,7 +43,7 @@
 
 #ifdef USE_4OPT
 
-//Utility macros for for 1,2,4 channel images:
+//Utility macros for 1,2,4 channel images:
 //  - LOAD4/STORE4 - load/store 4-pixel groups from/to global memory
 
 //  - SHUFFLE4_3/SHUFFLE4_5 - rearrange scattered border/central pixels into regular 4-pixel variables
diff --git a/modules/imgproc/test/test_convhull.cpp b/modules/imgproc/test/test_convhull.cpp
index ab1b464eb1..14f560b97e 100644
--- a/modules/imgproc/test/test_convhull.cpp
+++ b/modules/imgproc/test/test_convhull.cpp
@@ -1015,7 +1015,7 @@ int CV_MinCircleTest::validate_test_results( int test_case_idx )
     if( point_count >= 2 && (j < 2 || (j == 2 && cvTsDist(v[0],v[1]) < (radius-1)*2/eps)) )
     {
         ts->printf( cvtest::TS::LOG,
-            "There should be at at least 3 points near the circle boundary or 2 points on the diameter\n" );
+            "There should be at least 3 points near the circle boundary or 2 points on the diameter\n" );
         code = cvtest::TS::FAIL_BAD_ACCURACY;
         goto _exit_;
     }
diff --git a/modules/js/test/test_imgproc.js b/modules/js/test/test_imgproc.js
index ada315b390..a0d2d937cc 100644
--- a/modules/js/test/test_imgproc.js
+++ b/modules/js/test/test_imgproc.js
@@ -948,7 +948,7 @@ QUnit.test('test_filter', function(assert) {
 
         cv.rotate(src, dst, cv.ROTATE_90_CLOCKWISE);
 
-        size = dst.size();
+        let size = dst.size();
         assert.equal(size.height, 2, "ROTATE_HEIGHT");
         assert.equal(size.width, 3, "ROTATE_WIGTH");
 
diff --git a/modules/ml/src/lr.cpp b/modules/ml/src/lr.cpp
index ed4fb4c720..b43e104045 100644
--- a/modules/ml/src/lr.cpp
+++ b/modules/ml/src/lr.cpp
@@ -126,7 +126,7 @@ bool LogisticRegressionImpl::train(const Ptr<TrainData>& trainData, int)
     int num_classes = (int) this->forward_mapper.size();
     if(num_classes < 2)
     {
-        CV_Error( CV_StsBadArg, "data should have atleast 2 classes" );
+        CV_Error( CV_StsBadArg, "data should have at least 2 classes" );
     }
 
     // add a column of ones to the data (bias/intercept term)
diff --git a/modules/video/src/kalman.cpp b/modules/video/src/kalman.cpp
index f90f9f7b9e..10e7ffbe02 100644
--- a/modules/video/src/kalman.cpp
+++ b/modules/video/src/kalman.cpp
@@ -96,7 +96,7 @@ const Mat& KalmanFilter::predict(const Mat& control)
     // P'(k) = temp1*At + Q
     gemm(temp1, transitionMatrix, 1, processNoiseCov, 1, errorCovPre, GEMM_2_T);
 
-    // handle the case when there will be measurement before the next predict.
+    // handle the case when there will be no measurement before the next predict.
     statePre.copyTo(statePost);
     errorCovPre.copyTo(errorCovPost);
 
diff --git a/modules/videoio/src/cap_gstreamer.cpp b/modules/videoio/src/cap_gstreamer.cpp
index 16b09cc590..cdf8d47249 100644
--- a/modules/videoio/src/cap_gstreamer.cpp
+++ b/modules/videoio/src/cap_gstreamer.cpp
@@ -475,7 +475,7 @@ bool GStreamerCapture::setAudioProperties(const cv::VideoCaptureParameters& para
 /*!
  * \brief CvCapture_GStreamer::grabFrame
  * \return
- * Grabs a sample from the pipeline, awaiting consumation by retreiveFrame.
+ * Grabs a sample from the pipeline, awaiting consumation by retrieveFrame.
  * The pipeline is started if it was not running yet
  */
 bool GStreamerCapture::grabFrame()
diff --git a/modules/videoio/test/test_video_io.cpp b/modules/videoio/test/test_video_io.cpp
index 2ed1267433..f1ead09c23 100644
--- a/modules/videoio/test/test_video_io.cpp
+++ b/modules/videoio/test/test_video_io.cpp
@@ -224,7 +224,7 @@ public:
             if (cvtest::debugLevel > 0)
                 std::cout << "i = " << i << ": timestamp = " << timestamp << std::endl;
             const double frame_period = 1000.f/bunny_param.getFps();
-            // NOTE: eps == frame_period, because videoCapture returns frame begining timestamp or frame end
+            // NOTE: eps == frame_period, because videoCapture returns frame beginning timestamp or frame end
             // timestamp depending on codec and back-end. So the first frame has timestamp 0 or frame_period.
             EXPECT_NEAR(timestamp, i*frame_period, frame_period) << "i=" << i;
         }