diff --git a/.github/workflows/bak/cpythonlinuxIOnonregression.yml b/.github/workflows/bak/cpythonlinuxIOnonregression.yml
index 7aa8cd88..47c9fdfb 100644
--- a/.github/workflows/bak/cpythonlinuxIOnonregression.yml
+++ b/.github/workflows/bak/cpythonlinuxIOnonregression.yml
@@ -21,7 +21,9 @@ jobs:
         python-version: [3.7]
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
+      with:
+        submodules: true
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v1
       with:
@@ -41,12 +43,10 @@ jobs:
     - name: Build gmic-cli if needed
       run: |
         sudo apt-get install -y libfftw3-dev libcurl4-openssl-dev libpng-dev zlib1g-dev libomp5 libomp-dev
-        bash build_tools.bash 1b_clean_and_regrab_gmic_src_and_make_cli
       if: steps.cache-gmic-cli.outputs.cache-hit != 'true'
     - name: Build gmic-py if needed
       run: |
         sudo apt-get install -y libfftw3-dev libcurl4-openssl-dev libpng-dev zlib1g-dev libomp5 libomp-dev
-        bash build_tools.bash 1_clean_and_regrab_gmic_src
         bash build_tools.bash 2_compile
       if: steps.cache-gmic-py.outputs.cache-hit != 'true'
     - name: run IO non regression tests using compiled gmic-py and gmic-cli
diff --git a/.github/workflows/bak/cpythonmacosbuild_nosendpypi.yml b/.github/workflows/bak/cpythonmacosbuild_nosendpypi.yml
index dfde44bc..130b0ff5 100644
--- a/.github/workflows/bak/cpythonmacosbuild_nosendpypi.yml
+++ b/.github/workflows/bak/cpythonmacosbuild_nosendpypi.yml
@@ -11,7 +11,10 @@ jobs:
       matrix:
         python-version: [3.7]
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
+        with:
+          submodules: true
+
       # Prevent running this job on tag-based releases
       - name: Check if Git tag exists
         run: echo "HEAD_TAG=$(git tag --points-at HEAD)" >> $GITHUB_ENV
@@ -46,7 +49,6 @@ jobs:
           # llvm 9 (latest) might cause issue with c++20 pre-support, see https://trac.macports.org/ticket/59575 and https://github.com/dtschump/gmic-py/commit/618d9d317d55aa7af3f85e92bfd07f06efea491f/checks?check_suite_id=368364476
           # using llvm v6 instead
           brew install pkg-config fftw libpng libomp llvm@6 coreutils
-          bash build_tools.bash 1_clean_and_regrab_gmic_src
           MACOSX_DEPLOYMENT_TARGET=10.10 pip install git+https://github.com/mayeut/cibuildwheel.git
           MACOSX_DEPLOYMENT_TARGET=10.10 python -m cibuildwheel --output-dir wheelhouse
           echo "Mac OS wheelhouse after cibuildwheel looks like:"
diff --git a/.github/workflows/bak/cpythonmacosbuildandreleaseontag.yml b/.github/workflows/bak/cpythonmacosbuildandreleaseontag.yml
index 0f44cf02..02b13148 100644
--- a/.github/workflows/bak/cpythonmacosbuildandreleaseontag.yml
+++ b/.github/workflows/bak/cpythonmacosbuildandreleaseontag.yml
@@ -15,7 +15,10 @@ jobs:
       matrix:
         python-version: [3.7]
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
+        with:
+          submodules: true
+
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v1
         with:
@@ -42,7 +45,6 @@ jobs:
           # llvm 9 (latest) might cause issue with c++20 pre-support, see https://trac.macports.org/ticket/59575 and https://github.com/dtschump/gmic-py/commit/618d9d317d55aa7af3f85e92bfd07f06efea491f/checks?check_suite_id=368364476
           # using llvm v6 instead
           brew install pkg-config fftw libpng libomp llvm@6 coreutils
-          bash build_tools.bash 1_clean_and_regrab_gmic_src
           MACOSX_DEPLOYMENT_TARGET=10.10 pip install git+https://github.com/mayeut/cibuildwheel.git
           MACOSX_DEPLOYMENT_TARGET=10.10 python -m cibuildwheel --output-dir wheelhouse && bash build_tools.bash 11_send_to_pypi
           echo "Mac OS wheelhouse after cibuildwheel and sending to pypi.org looks like:"
diff --git a/.github/workflows/bak/cpythonmanylinuxbuild_nosendpypi.yml b/.github/workflows/bak/cpythonmanylinuxbuild_nosendpypi.yml
index 90ed9f7a..5aaac4dd 100644
--- a/.github/workflows/bak/cpythonmanylinuxbuild_nosendpypi.yml
+++ b/.github/workflows/bak/cpythonmanylinuxbuild_nosendpypi.yml
@@ -21,7 +21,10 @@ jobs:
             docker_image: 'quay.io/pypa/manylinux2014_x86_64:latest'
             pre_cmd:
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
+        with:
+          submodules: true
+
       # Prevent running this job on tag-based releases
       - name: Check if Git tag exists
         run: echo "HEAD_TAG::$(git tag --points-at HEAD)" >> $GITHUB_ENV
diff --git a/.github/workflows/bak/cpythonmanylinuxbuildandreleaseontag.yml b/.github/workflows/bak/cpythonmanylinuxbuildandreleaseontag.yml
index 0f9d9993..9a3cd745 100644
--- a/.github/workflows/bak/cpythonmanylinuxbuildandreleaseontag.yml
+++ b/.github/workflows/bak/cpythonmanylinuxbuildandreleaseontag.yml
@@ -23,7 +23,10 @@ jobs:
             docker_image: 'quay.io/pypa/manylinux2014_x86_64:latest'
             pre_cmd:
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
+        with:
+          submodules: true
+
       # Detect G'MIC target version from VERSION file
       - name: Detect G'MIC target version
         run: echo "GHA_GMIC_VERSION=$(GHA_QUIET=1 bash build_tools.bash __get_py_package_version)" >> $GITHUB_ENV
diff --git a/.github/workflows/bak/cpythonpythonpackageoptimized.yml b/.github/workflows/bak/cpythonpythonpackageoptimized.yml
index f81ba471..03350448 100644
--- a/.github/workflows/bak/cpythonpythonpackageoptimized.yml
+++ b/.github/workflows/bak/cpythonpythonpackageoptimized.yml
@@ -43,7 +43,6 @@ jobs:
         bash build_tools.bash 21_check_c_style # should stop this script on style error
         bash build_tools.bash 23_check_python_style # should stop this script on style error
 
-        bash build_tools.bash 1_clean_and_regrab_gmic_src
         bash build_tools.bash 2_compile #2b_compile_debug
         bash build_tools.bash 3_test_compiled_so
         # && bash build_tools.bash 11_send_to_pypi #Note that most probably nothing will be sent to PyPI because of too modern linked libraries 
diff --git a/.github/workflows/bak/cpythonwindowsbuild.yml b/.github/workflows/bak/cpythonwindowsbuild.yml
index 4237473d..a8484b89 100644
--- a/.github/workflows/bak/cpythonwindowsbuild.yml
+++ b/.github/workflows/bak/cpythonwindowsbuild.yml
@@ -7,31 +7,62 @@ on: [push]
 jobs:
   build-windows:
     runs-on: windows-latest
-    strategy:
-      matrix:
-        python-version: ['3.7']
+    defaults:
+      run:
+        shell: msys2 {0}
     steps:
-      - uses: actions/checkout@v1
-      - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v1
+      - uses: actions/checkout@v2
         with:
-          python-version: ${{ matrix.python-version }}
-      - name: build on macos
+          submodules: true
+
+      # Using https://github.com/marketplace/actions/setup-msys2
+      - name: Using "Setup MSYS2" contrib
+        uses: msys2/setup-msys2@v2
+        with:
+          update: true
+          install: make git
+      - run: git describe --dirty
+      - name: build on windows
         working-directory: ./
         env:
           TWINE_PASSWORD_GITHUB_SECRET: ${{ secrets.TWINE_PASSWORD_GITHUB_SECRET }} # For build_tools.bash 11_send_to_pypi
-          PYTHON3: python
-          PIP3: pip
-          CIBW_BUILD: cp3*-*win*
-          # CIBW_ENVIRONMENT: "CC='/usr/local/opt/llvm@6/bin/clang' CXX='/usr/local/opt/llvm@6/bin/clang++' COMPILER_INDEX_STORE_ENABLE='NO'"
-          CIBW_BEFORE_BUILD: pip install -r dev-requirements.txt
-          CIBW_TEST_REQUIRES: pytest
-          CIBW_TEST_COMMAND: python -W default -m pytest {project}/tests/test_gmic_py.py -vvv -rxXs
-          CIBW_BUILD_VERBOSITY: 3
         run: |
-          # brew install pkg-config fftw libpng libomp llvm@6
-          bash build_tools.bash 1_clean_and_regrab_gmic_src
-          pip install git+https://github.com/joerick/cibuildwheel.git
-          python -m cibuildwheel --output-dir wheelhouse
-          #echo "Mac OS wheelhouse after cibuildwheel looks like:"
-          #bash build_tools.bash 11_send_to_pypi
+          pacman --noconfirm -S unzip wget mingw-w64-x86_64-curl mingw-w64-x86_64-python-pip mingw-w64-x86_64-python python-devel mingw-w64-x86_64-gcc mingw-w64-x86_64-zlib mingw-w64-x86_64-libjpeg-turbo mingw64/mingw-w64-x86_64-pkgconf mingw-w64-x86_64-libpng mingw-w64-x86_64-libtiff mingw64/mingw-w64-x86_64-fftw
+          pacman --noconfirm -S mingw-w64-x86_64-python-numpy # used by unit tests, safer to install so than through pip on-the-fly source compilation
+          # Add complementary pkg-config .pc lookup path
+          export PKG_CONFIG_PATH=/usr/lib/pkgconfig/:$PKG_CONFIG_PATH
+          pkg-config --list-all
+          pkg-config libjpeg --libs --cflags
+          pkg-config libpng --libs --cflags
+          pkg-config libtiff-4 --libs --cflags
+          pkg-config zlib --libs --cflags
+          pkg-config libcurl --libs --cflags
+          pkg-config libcurl --libs --cflags
+          which python
+          python --version
+          gcc --version
+          g++ --version
+          which pip
+          pip --version
+          pip install -r dev-requirements.txt
+          bash build_tools.bash 2b_compile_debug
+          ldd $(find -name *.dll)
+          bash build_tools.bash 3_test_compiled_so format
+          bash build_tools.bash 4b_build_windows_portable_wheel
+          bash build_tools.bash 5_test_wheel format
+          bash build_tools.bash 5b_test_wheel_dlls_repaired
+      - name: upload .whl debug build dir as artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: gmic-py-windows-debug-dist-dir
+          path: dist/
+      - name: upload .whl repaired build dir as artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: gmic-py-windows-repaired-dist-dir
+          path: wheelhouse/
+      - name: upload .dll debug build dir as artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: gmic-py-windows-debug-build-dir
+          path: build/
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 00000000..f419d706
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,100 @@
+# Automatically build binary wheels and source packages.
+# Adapted from https://github.com/vinayak-mehta/pdftopng/blob/main/.github/workflows/build.yml
+name: cibuildwheel
+
+on: [push]
+
+env:
+  CIBW_BUILD: "cp3?-manylinux_x86_64 cp3?-macosx_x86_64"
+  CIBW_SKIP: "cp35-*"
+  CIBW_BEFORE_BUILD_LINUX: "sh scripts/build_linux.sh"
+  CIBW_REPAIR_WHEEL_COMMAND_LINUX: "LD_LIBRARY_PATH=$(pwd)/lib/poppler/build/:$LD_LIBRARY_PATH auditwheel repair -w {dest_dir} {wheel}"
+  CIBW_BEFORE_BUILD_MACOS: "sh scripts/build_macos.sh"
+  CIBW_REPAIR_WHEEL_COMMAND_MACOS: "DYLD_LIBRARY_PATH=$(pwd)/lib/poppler/build:$DYLD_LIBRARY_PATH delocate-listdeps {wheel} && delocate-wheel -w {dest_dir} -v {wheel}"
+  CIBW_REPAIR_WHEEL_COMMAND_WINDOWS: "call scripts/wheel_repair.bat {wheel} {dest_dir}"
+
+jobs:
+  build_wheels:
+    name: Build wheels on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [windows-latest]
+
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: true
+      - uses: actions/setup-python@v2
+        name: Install Python
+        with:
+          python-version: 3.8
+
+      - uses: ilammy/msvc-dev-cmd@v1
+        with:
+          arch: x86
+
+      - name: Build dependencies & wheels (Windows / x86)
+        if: runner.os == 'Windows'
+        shell: cmd
+        run: |
+          REM call scripts\build_win_x86.bat
+          cd gmic
+          git fetch --all --tags
+          git checkout v.2.9.1
+          cd ..
+          C:\msys64\usr\bin\wget.exe -P gmic\src https://gmic.eu/gmic_stdlib.h
+          C:\msys64\usr\bin\wget.exe -P gmic\src https://github.com/dtschump/CImg/raw/v.2.9.1/CImg.h
+          vcpkg install libpng:x64-windows libjpeg-turbo:x64-windows zlib:x64-windows curl:x64-windows tiff:x64-windows fftw3:x64-windows
+          vcpkg list
+          python -m pip --disable-pip-version-check install cibuildwheel==1.6.1 wheel
+          python setup.py bdist_wheel 
+          REM python -m cibuildwheel --output-dir wheelhouse
+        env:
+          CIBW_BUILD: "cp3?-win32"
+          CIBW_SKIP: "cp35-*"
+          DISTUTILS_USE_SDK: 1
+          MSSdk: 1
+
+#      - uses: ilammy/msvc-dev-cmd@v1
+#        with:
+#          arch: amd64
+#
+#      - name: Build dependencies & wheels (Windows / amd64)
+#        if: runner.os == 'Windows'
+#        shell: cmd
+#        run: |
+#          call scripts\build_win_x64.bat
+#          python -m pip --disable-pip-version-check install cibuildwheel==1.6.1
+#          python -m cibuildwheel --output-dir wheelhouse
+#        env:
+#          CIBW_BUILD: "cp3?-win_amd64"
+#          CIBW_SKIP: "cp35-*"
+#          DISTUTILS_USE_SDK: 1
+#          MSSdk: 1
+#
+#      - name: Install cibuildwheel & build wheels (Linux & MacOS)
+#        if: runner.os != 'Windows'
+#        run: |
+#          python -m pip --disable-pip-version-check install cibuildwheel==1.6.1
+#          python -m cibuildwheel --output-dir wheelhouse
+#
+#      - uses: actions/upload-artifact@v2
+#        with:
+#          path: ./wheelhouse/*.whl
+#
+#  upload_pypi:
+#    needs: [build_wheels]
+#    runs-on: ubuntu-latest
+#    # upload to PyPI on every tag starting with 'v'
+#    if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags/v')
+#    steps:
+#      - uses: actions/download-artifact@v2
+#        with:
+#          name: artifact
+#          path: dist
+#
+#      - uses: pypa/gh-action-pypi-publish@master
+#        with:
+#          user: __token__
+#          password: ${{ secrets.pypi_password }}
diff --git a/.github/workflows/cpythonpythonpackage.yml b/.github/workflows/cpythonpythonpackage.yml
index 23843f50..5cac85bb 100644
--- a/.github/workflows/cpythonpythonpackage.yml
+++ b/.github/workflows/cpythonpythonpackage.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v1
+
 
     # Prevent running this job on tag-based releases
     - name: Check if Git tag exists
@@ -28,6 +28,10 @@ jobs:
       with:
         python-version: 3.7
 
+    - uses: actions/checkout@v2
+      with:
+        submodules: true
+
     - name: Compile and run tests on .so, .whl and source distribution of gmic-py ${{ env.GHA_GMIC_VERSION }}
       working-directory: ./
       env:
@@ -35,13 +39,18 @@ jobs:
         PYTHON3: python3
         PIP3: pip3
       run: |
+        cd gmic
+        git fetch --all --tags
+        git checkout v.2.9.1
+        cd ..
         for apt_file in `grep -lr microsoft /etc/apt/sources.list.d/`; do sudo rm $apt_file; done
         sudo apt-get update; sudo apt-get install -y libfftw3-dev libcurl4-openssl-dev libpng-dev zlib1g-dev libomp5 libomp-dev
         sudo apt-get install clang-format
         bash build_tools.bash 21_check_c_style # should stop this script on style error
         bash build_tools.bash 23_check_python_style # should stop this script on style error
+        wget -P gmic/src https://gmic.eu/gmic_stdlib.h
+        wget -P gmic/src https://github.com/dtschump/CImg/raw/v.2.9.1/CImg.h
 
-        bash build_tools.bash 1_clean_and_regrab_gmic_src
         bash build_tools.bash 2b_compile_debug
         ldd build/lib.linux-x86_64-3.*/gmic.cpython-3*-x86_64-linux-gnu.so
         # bash build_tools.bash 3_test_compiled_so # TODO tests exceptionnally disabled for remote testing
diff --git a/.gitignore b/.gitignore
index 66a01720..c1e4ef77 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,7 +3,6 @@ src/
 out.json
 build/
 dist/
-gmic
 docs/_build/
 wheelhouse/*
 *.egg-info*
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 00000000..ac294e07
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,4 @@
+[submodule "gmic"]
+	path = gmic
+	url = https://github.com/dtschump/gmic
+	branch = tags/2.9.1
diff --git a/build_tools.bash b/build_tools.bash
index b1020acd..a1ec159c 100644
--- a/build_tools.bash
+++ b/build_tools.bash
@@ -5,6 +5,8 @@ PYTHON3=${PYTHON3:-python3}
 PIP3=${PIP3:-pip3}
 PYTHON_VERSION=$($PYTHON3 --version | cut -d' ' -f2 | cut -d'.' -f1,2)
 
+WIN_DLL_DIR="win_dll" # Directory where gmic-py dependents .dll files will be stored
+
 # Detect if Python is a debug build, per https://stackoverflow.com/a/647312/420684
 # Useful for testing leaks within the compiled .so library
 if python -c "import sys; sys.exit(int(hasattr(sys, 'gettotalrefcount')))"; then
@@ -47,7 +49,7 @@ function __get_py_package_version () {
 
 function 00_all_steps () {
     # See related but defunct Dockerfile at https://github.com/myselfhimself/gmic-py/blob/fc12cb74f4b02fbfd83e9e9fba44ba7a4cee0d93/Dockerfile
-    21_check_c_style && 23_check_python_style && 1_clean_and_regrab_gmic_src && 2_compile && 3_test_compiled_so && 4_build_wheel && 5_test_wheel && 6_build_sdist && 7_test_sdist
+    21_check_c_style && 23_check_python_style && 2_compile && 3_test_compiled_so && 4_build_wheel && 5_test_wheel && 6_build_sdist && 7_test_sdist
     echo "This is the final file tree:"
     find .
 }
@@ -108,6 +110,7 @@ function 11_send_to_pypi () {
     set +x
 }
 
+# Now replaced by git submodule, kept for legacy
 function 1_clean_and_regrab_gmic_src () {
     set -x
     GMIC_ARCHIVE_GLOB=gmic_${GMIC_VERSION}.tar.gz
@@ -217,24 +220,40 @@ function 33_build_manylinux () {
 }
 
 function 3_test_compiled_so () {
+    set -x
     # Example usage: <this_script.bash> 3_test_compiled_so my_pytest_expr ====> pytest <the pytest file> -k my_pytest_expr
     # Example usage: <this_script.bash> 3_test_compiled_so my_pytest_expr -x --pdb ====> pytest <the pytest file> -k my_pytest_expr -x --pdb
     PYTEST_EXPRESSION_PARAM=
     if ! [ -z "$1" ]; then
         PYTEST_EXPRESSION_PARAM="-k ${@:1}"
     fi
-    if ! [ -z "$PYTHON_DEBUG" ]; then
-        GMIC_LIB_DIR="./build/lib*$PYTHON_VERSION*debug*/"
+
+    # No python path must be set for the case 5_test_wheel
+    # Otherwise add the path of directory containing .so (debugging or optimized version)
+    if [ -z "$TEST_WHEEL" ]; then
+	pip uninstall gmic -y
+        if ! [ -z "$PYTHON_DEBUG" ]; then
+            export PYTHONPATH=$(readlink -f ./build/lib*$PYTHON_VERSION*debug*/)
+        else
+            export PYTHONPATH=$(readlink -f ./build/lib*$PYTHON_VERSION/)
+        fi
     else
-        GMIC_LIB_DIR="./build/lib*$PYTHON_VERSION/"
+	export PYTHONPATH=""
     fi
-    TEST_FILES="${TEST_FILES:-../../tests/test_gmic_py.py ../../tests/test_gmic_numpy.py ../../tests/test_gmic_numpy_toolkits.py ../../tests/test_gmic_py_memfreeing.py}"
-    #TEST_FILES="${TEST_FILES:-../../tests/test_gmic_py_memfreeing.py}"
+    $PYTHON3 -c "import gmic; print(gmic.__spec__)"
+    ls -l $PYTHONPATH
+
+    TEST_FILES="${TEST_FILES:-tests/test_gmic_py.py tests/test_gmic_numpy.py tests/test_gmic_numpy_toolkits.py tests/test_gmic_py_memfreeing.py}"
+
+    REQUIREMENTS="-r dev-requirements.txt  -r test-requirements.txt"
+    if ! [ -z "$MSYSTEM" ]; then #windows / msys2 related
+        REQUIREMENTS="-r dev-requirements.txt  -r test-requirements-win.txt"
+    fi
+    #TEST_FILES="${TEST_FILES:-tests/test_gmic_py_memfreeing.py}"
     FAILED_SUITES=0
-    $PIP3 uninstall gmic -y; cd $GMIC_LIB_DIR ; LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH ; $PIP3 install -r ../../dev-requirements.txt ; pwd; ls; 
+    $PIP3 install $REQUIREMENTS; pwd; ls; 
 
     for TEST_FILE in $TEST_FILES; do
-        # $PIP3 uninstall gmic -y; cd $GMIC_LIB_DIR ; LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH ; $PIP3 install -r ../../dev-requirements.txt ; pwd; ls; PYTHONMALLOC=malloc valgrind --show-leak-kinds=all --leak-check=full --log-file=/tmp/valgrind-output $PYTHON3 -m pytest $TEST_FILES $PYTEST_EXPRESSION_PARAM -vvv -rxXs || { echo "Fatal error while running pytests" ; exit 1 ; } ; cd ../..
         $PYTHON3 -m pytest $TEST_FILE $PYTEST_EXPRESSION_PARAM -vvv -rxX || { echo "Fatal error while running pytest suite $TEST_FILE" ; FAILED_SUITES=$((FAILED_SUITES+1)) ; }
     done
     cd ../..
@@ -244,10 +263,12 @@ function 3_test_compiled_so () {
     else
         return 0;
     fi
+    export PYTHONPATH=""
+    set +x
 }
 
 function 3b_test_compiled_so_no_numpy () {
-    TEST_FILES="../../tests/test_gmic_py.py" 3_test_compiled_so
+    TEST_FILES="tests/test_gmic_py.py" 3_test_compiled_so
 }
 
 function 31_test_compiled_so_filters_io () {
@@ -269,20 +290,72 @@ function 31_test_compiled_so_filters_io () {
         PYTEST_NB_THREADS="-n 4"
     fi
     find ~/.config/gmic
-    $PIP3 uninstall gmic -y; cd ./build/lib*$PYTHON_VERSION*/ ; LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH ; $PIP3 install -r ../../dev-requirements.txt ; pwd; ls; $PYTHON3 -m pytest ../../tests/test_gmic_py_filters_io.py $PYTEST_EXPRESSION_PARAM $PYTEST_NB_THREADS -vvv -rxXs || { echo "Fatal error while running pytests" ; exit 1 ; } ; cd ../..
+    $PIP3 uninstall gmic -y; cd ./build/lib*$PYTHON_VERSION*/ ; export PYTHONPATH=`pwd` ; $PIP3 install -r ../../{test,dev}-requirements.txt ; pwd; ls; $PYTHON3 -m pytest ../../tests/test_gmic_py_filters_io.py $PYTEST_EXPRESSION_PARAM $PYTEST_NB_THREADS -vvv -rxXs || { echo "Fatal error while running pytests" ; exit 1 ; } ; cd ../..
     find ~/.config/gmic
 }    
 
 function 4_build_wheel () {
+    rm -rf .egg-info # https://stackoverflow.com/questions/18085571/pip-install-error-setup-script-specifies-an-absolute-path#comment94579634_39198529
+
     $PIP3 install wheel || { echo "Fatal wheel package install error" ; exit 1 ; }
     $PYTHON3 setup.py bdist_wheel || { echo "Fatal wheel build error" ; exit 1 ; }
-    echo "Not doing any auditwheel repair step here, development environment :)"
+
+    if [ -z "WHEEL_REPAIR" ]; then
+        echo "Not doing any auditwheel repair step here, development environment :)"
+    elif ! [ -z "$MSYSTEM" ]; then
+	echo "about to repair wheel for windows using wheel_repair.py"
+	echo ".dll ldd for info, before repair attempt:"
+	ldd build/lib.*/gmic-*.dll
+	#4c_copy_windows_dlls_for_repair
+	pip install -r dev-requirements-win.txt
+        LAST_WHEEL=`ls -Art dist/*.whl | tail -n 1`
+	$PYTHON3 wheel_repair.py $LAST_WHEEL -d "D:/a/_temp/msys/msys64/mingw64/bin/"
+    fi
+}
+
+function 4b_build_windows_portable_wheel () {
+   WHEEL_REPAIR=1 4_build_wheel
+}
+
+
+function 4c_copy_windows_dlls_for_repair () {
+    set -x
+    # Inspired by gmic CLI Windows build instructions at https://gmic.eu/download.html#windows
+    mkdir -p $WIN_DLL_DIR
+    DLLS_TO_COPY=$(ldd build/lib.*/gmic-*.dll | grep -Eio "/mingw64/bin/.*.dll" | paste -s -d' ')
+    echo "DLLs to be copied into wheel are: $DLLS_TO_COPY"
+    cp $DLLS_TO_COPY $WIN_DLL_DIR || { echo "Could not copy dlls to $WIN_DLL_DIR" ; exit 1 ; }
+    find $WIN_DLL_DIR
+    set +x
 }
 
 function 5_test_wheel () {
-    $PIP3 install dist/gmic*.whl --no-cache-dir
-    $PYTHON3 -m pytest tests/test_gmic_py.py -rxXs -vvv
+    set -x
+    export PYTHONPATH=""
+    $PIP3 install `ls -Art dist/*.whl | tail -n 1` --no-cache-dir
+    TEST_WHEEL=1 3_test_compiled_so ${@:1}
+    $PIP3 uninstall gmic -y
+    set +x
+}
+
+function 5b_test_wheel_dlls_repaired () {
+    set -x
+    LAST_WHEEL=`ls -Art wheelhouse/*.whl | tail -n 1`
+    unzip -l $LAST_WHEEL
+    PACKED_DLLS_FOUND=`unzip -l $LAST_WHEEL | grep -Eio "[a-z].*\.dll" | grep -v gmic-cpython | paste -s -d' '`
+    if [ -z "$PACKED_DLLS_FOUND" ]; then
+        echo "Error: non-gmic DLLs not found in wheel."; exit 1
+    else
+        echo "Found non-gmic DLLs in wheel: $PACKED_DLLS_FOUND"
+    fi
+
+    export PYTHONPATH=""
+    $PIP3 uninstall gmic -y
+    $PIP3 install $LAST_WHEEL --no-cache-dir
+    TEST_WHEEL=1 3_test_compiled_so ${@:1}
     $PIP3 uninstall gmic -y
+ 
+    set +x
 }
 
 function 6_make_full_doc () {
diff --git a/dev-requirements-win.txt b/dev-requirements-win.txt
new file mode 100644
index 00000000..32f38cba
--- /dev/null
+++ b/dev-requirements-win.txt
@@ -0,0 +1,7 @@
+# Requirements for a local developer environment and for CI building (shared library and wheel-level)
+wheel
+pkgconfig
+pefile
+machomachomangler
+
+# Do not put the 'black' Python code formatter as a dependency here it will not install for Python <= 3.6 and crash the Mac OS CI, black must be installed at formatting check time, outside any docker wheel-building environment. See the related formatting functions in build_tools.bash script.
diff --git a/dev-requirements.txt b/dev-requirements.txt
index c3cacd9c..008353e7 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -1,11 +1,5 @@
-# Requirements for a local developer environment and for CI building (top and wheel-level)
+# Requirements for a local developer environment and for CI building (shared library and wheel-level)
 wheel
 pkgconfig
-#scikit-image
-numpy #==1.16.1 # fixes https://github.com/scikit-image/scikit-image/issues/3655
-Pillow
-pytest
-setuptools
-pytest-xdist #allow parallelization
-psutil
+
 # Do not put the 'black' Python code formatter as a dependency here it will not install for Python <= 3.6 and crash the Mac OS CI, black must be installed at formatting check time, outside any docker wheel-building environment. See the related formatting functions in build_tools.bash script.
diff --git a/gmic b/gmic
new file mode 160000
index 00000000..0c98c226
--- /dev/null
+++ b/gmic
@@ -0,0 +1 @@
+Subproject commit 0c98c226a68bd582600eefe5eadd7118410d4c82
diff --git a/gmicpy.h b/gmicpy.h
index 9f24713f..9c9d0eb1 100644
--- a/gmicpy.h
+++ b/gmicpy.h
@@ -1,4 +1,4 @@
-#include "gmic.h"
+#include "gmic/src/gmic.h"
 
 // Set T be a float if not platform-overridden
 #ifndef T
diff --git a/setup.cfg b/setup.cfg
index ad150636..e4b0810b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,4 +1,4 @@
 [metadata]
 # This includes the license file(s) in the wheel.
 # https://wheel.readthedocs.io/en/stable/user_guide.html#including-license-files-in-the-generated-wheel-file
-license_files = COPYING
+license_file = COPYING
diff --git a/setup.py b/setup.py
index e513c448..162dc0c3 100644
--- a/setup.py
+++ b/setup.py
@@ -2,21 +2,30 @@
 """
 
 from os import path, listdir, environ
+import os
 import sys
-import platform
 
 from setuptools import setup, Extension, find_packages
-import pkgconfig
+
+try:
+    import pkgconfig
+except:
+    print("No pkgconfig found")
+
+IS_WINDOWS = sys.platform == "win32"
 
 here = path.abspath(path.dirname(__file__))
-gmic_src_path = path.abspath("src/gmic/src")
+gmic_src_path = path.abspath("gmic/src")
+WIN_DLL_DIR = path.abspath("win_dll")
+
+debug_enabled = "--debug" in sys.argv
 
 
 # List of non-standard '-l*' compiler parameters
 extra_link_args = []
 
-# List of libs to get include directories and linkable libraries paths from for compiling
-pkgconfig_list = ["zlib"]
+# Extra C flags
+extra_compile_args = []
 
 # Macros to toggle (gmic or CImg will do C/C++ #ifdef checks on them, testing mostly only their existence)
 # cimg_date and cimg_date are true variables, the value of which is checked in the C/C++ source
@@ -34,68 +43,91 @@
     ),  # "display" statements display for Jupyter/Ipython
 ]
 
-# Only require x11 if found
-if pkgconfig.exists("x11"):
-    define_macros += [("cimg_display", None)]
-    pkgconfig_list += ["x11"]
+# UNIX build flags pregeneration
+if not IS_WINDOWS:
 
-# Only require libpng if found
-if pkgconfig.exists("libpng"):
-    define_macros += [("cimg_use_png", None)]
-    pkgconfig_list += ["libpng"]
+    extra_compile_args.extend(["-std=c++11"])
+    if debug_enabled:
+        extra_compile_args += ["-O0"]
+        extra_compile_args += ["-g"]
+    else:
+        extra_compile_args += ["-Ofast", "-flto"]
+        extra_link_args += ["-flto"]
 
-# Only require libtiff if found
-if pkgconfig.exists("libtiff-4"):
-    define_macros += [("cimg_use_tiff", None)]
-    pkgconfig_list += ["libtiff-4"]
+    # List of libs to get include directories and linkable libraries paths from for compiling
+    pkgconfig_list = ["zlib"]
 
-# Only require libjpeg if found
-if pkgconfig.exists("libjpeg"):
-    define_macros += [("cimg_use_jpeg", None)]
-    pkgconfig_list += ["libjpeg"]
+    # Only require x11 if found
+    if pkgconfig.exists("x11"):
+        define_macros += [("cimg_display", None)]
+        pkgconfig_list += ["x11"]
 
-# Only require fftw3 if found (non-2^ size image processing fails without it)
-# We do not toggle cimg_use_fftw3, it is buggy
-if pkgconfig.exists("fftw3"):
-    define_macros += [("cimg_use_fftw3", None)]
-    pkgconfig_list += ["fftw3"]
-    extra_link_args += ["-lfftw3_threads"]
+    # Only require libpng if found
+    if pkgconfig.exists("libpng"):
+        define_macros += [("cimg_use_png", None)]
+        pkgconfig_list += ["libpng"]
 
-# Only compile with OpenCV if exists (nice for the 'camera' G'MIC command :-D )
-if pkgconfig.exists("opencv"):
-    define_macros += [("cimg_use_opencv", None)]
-    pkgconfig_list += ["opencv"]
+    # Only require libtiff if found
+    if pkgconfig.exists("libtiff-4"):
+        define_macros += [("cimg_use_tiff", None)]
+        pkgconfig_list += ["libtiff-4"]
 
-if pkgconfig.exists("libcurl"):
-    define_macros += [("cimg_use_curl", None)]
-    pkgconfig_list += ["libcurl"]
+    # Only require libjpeg if found
+    if pkgconfig.exists("libjpeg"):
+        define_macros += [("cimg_use_jpeg", None)]
+        pkgconfig_list += ["libjpeg"]
 
-packages = pkgconfig.parse(" ".join(pkgconfig_list))
-libraries = packages["libraries"] + [
-    "pthread"
-]  # removed core-dumping 'gomp' temporarily (for manylinux builds)
+    # Only require fftw3 if found (non-2^ size image processing fails without it)
+    # We do not toggle cimg_use_fftw3, it is buggy
+    if pkgconfig.exists("fftw3"):
+        define_macros += [("cimg_use_fftw3", None)]
+        pkgconfig_list += ["fftw3"]
+        if sys.platform not in ("cygwin", "win32", "msys"):
+            extra_link_args += ["-lfftw3_threads"]
 
-library_dirs = packages["library_dirs"] + [here, gmic_src_path]
-if sys.platform == "darwin":
-    library_dirs += ["/usr/local/opt/llvm@6/lib"]
-include_dirs = packages["include_dirs"] + [here, gmic_src_path]
-if sys.platform == "darwin":
-    include_dirs += ["/usr/local/opt/llvm@6/include"]
-# Debugging is now set through --global-option --debug and more.
-# debugging_args = [
-#     "-O0",
-#     "-g",
-# ]  # Uncomment this for faster compilation with debug symbols and no optimization
+    # Only compile with OpenCV if exists (nice for the 'camera' G'MIC command :-D )
+    if pkgconfig.exists("opencv"):
+        define_macros += [("cimg_use_opencv", None)]
+        pkgconfig_list += ["opencv"]
 
-debug_enabled = "--debug" in sys.argv
+    if pkgconfig.exists("libcurl"):
+        define_macros += [("cimg_use_curl", None)]
+        pkgconfig_list += ["libcurl"]
+
+    packages = pkgconfig.parse(" ".join(pkgconfig_list))
+    libraries = packages["libraries"] + [
+        "pthread"
+    ]  # removed core-dumping 'gomp' temporarily (for manylinux builds)
 
-extra_compile_args = ["-std=c++11"]
-if debug_enabled:
-    extra_compile_args += ["-O0"]
-    extra_compile_args += ["-g"]
+    library_dirs = packages["library_dirs"] + [here, gmic_src_path]
+    if sys.platform == "darwin":
+        library_dirs += ["/usr/local/opt/llvm@6/lib"]
+    include_dirs = packages["include_dirs"] + [here, gmic_src_path]
+    if sys.platform == "darwin":
+        include_dirs += ["/usr/local/opt/llvm@6/include"]
+    # Debugging is now set through --global-option --debug and more.
+    # debugging_args = [
+    #     "-O0",
+    #     "-g",
+    # ]  # Uncomment this for faster compilation with debug symbols and no optimization
 else:
-    extra_compile_args += ["-Ofast", "-flto"]
-    extra_link_args += ["-flto"]
+    # WINDOWS build flags generation
+    x = "x64" if sys.maxsize > 2 ** 32 else "x86"
+    vcpkg_lib_dir = os.path.join(
+        os.environ["VCPKG_INSTALLATION_ROOT"], "installed", f"{x}-windows", "lib"
+    )
+    libraries = ["fftw3", "libpng16", "jpeg", "curl", "zlib", "tiff"]
+    library_dirs = [vcpkg_lib_dir, gmic_src_path]
+    include_dirs = [here, gmic_src_path]
+    define_macros = []
+    define_macros += [("cimg_use_curl", None)]
+    define_macros += [("cimg_use_fftw3", None)]
+    define_macros += [("cimg_display", None)]
+    define_macros += [("cimg_use_jpeg", None)]
+    define_macros += [("cimg_use_tiff", None)]
+    define_macros += [("cimg_use_png", None)]
+    define_macros += [("cimg_display", None)]
+    extra_compile_args.extend(["/std:c11", "/OpenMP"])
 
 if sys.platform == "darwin":
     extra_compile_args += ["-fopenmp", "-stdlib=libc++"]
@@ -104,26 +136,49 @@
         "-nodefaultlibs",
         "-lc++",
     ]  # options inspired by https://github.com/explosion/spaCy/blob/master/setup.py
-elif sys.platform == "linux":  # Enable openmp for 32bit & 64bit linuxes
+elif not IS_WINDOWS:
+    # Enable openmp for 32bit & 64bit linuxes and posix'ed windows
     extra_compile_args += ["-fopenmp"]
     extra_link_args += ["-lgomp"]
 
+package_data = {}
+# Force Windows and Windows posix'ed platforms as Windows-like for CImg/G'MIC
+# Also fix libcurl include and lib paths, which are not correctly mapped by pkg-config
+if sys.platform in ("msys", "cygwin", "win32"):
+    define_macros.append(("cimg_OS", "2"))
+    package_data = {"gmic": ["win_dll/*.dll"]}
+
+#    # MSYS2 / Github Action hack to fix libcurl
+#    extra_compile_args += ["-ID:/a/_temp/msys/msys64/usr/include"]
+#    extra_link_args += ["-LD:/a/_temp/msys/msys64/usr/lib"]
+
+
 print("Define macros:")
 print(define_macros)
 
-# Static CPython gmic.so embedding libgmic.so.2
-gmic_module = Extension(
-    "gmic",
+extension_kwargs = dict(
+    name="gmic",
     include_dirs=include_dirs,
     libraries=libraries,
     library_dirs=library_dirs,
-    sources=["gmicpy.cpp", path.join(gmic_src_path, "gmic.cpp")],
+    sources=[
+        "gmicpy.cpp",
+        path.join(gmic_src_path, "gmic.cpp"),
+    ],
     define_macros=define_macros,
     extra_compile_args=extra_compile_args,
     extra_link_args=extra_link_args,
     language="c++",
 )
 
+
+print("Extension options:")
+print(extension_kwargs)
+
+
+# Static CPython gmic.so embedding libgmic.so / .dll
+gmic_module = Extension(**extension_kwargs)
+
 # Get the long description from the README file
 with open(path.join(here, "README.md"), encoding="utf-8") as f:
     long_description = f.read()
@@ -136,64 +191,31 @@
 # Arguments marked as "Required" below must be included for upload to PyPI.
 # Fields marked as "Optional" may be commented out.
 
+
+def get_package_data():
+    """Return a list of DLL dependencies paths if on Windows platforms and DLL dir was prepared
+    Needs build_tools.bash 4b_build_windows_portable_wheel to be run first on Windows OS
+    Returns nothing quietly on other platforms
+    """
+    package_data = {}
+    if sys.platform in ("msys", "cygwin", "win32") and path.exists(WIN_DLL_DIR):
+        libfiles = listdir(WIN_DLL_DIR)
+        package_data["win_dll"] = libfiles
+
+    # TODO remove me
+    print("just built package_data:", package_data)
+    return package_data
+
+
 setup(
-    # This is the name of your project. The first time you publish this
-    # package, this name will be registered for you. It will determine how
-    # users can install this project, e.g.:
-    #
-    # $ pip install sampleproject
-    #
-    # And where it will live on PyPI: https://pypi.org/project/sampleproject/
-    #
-    # There are some restrictions on what makes a valid project name
-    # specification here:
-    # https://packaging.python.org/specifications/core-metadata/#name
-    name="gmic",  # Required
-    # Versions should comply with PEP 440:
-    # https://www.python.org/dev/peps/pep-0440/
-    #
-    # For a discussion on single-sourcing the version across setup.py and the
-    # project code, see
-    # https://packaging.python.org/en/latest/single_source_version.html
+    name="gmic",
     version=version,
-    # This is a one-line description or tagline of what your project does. This
-    # corresponds to the "Summary" metadata field:
-    # https://packaging.python.org/specifications/core-metadata/#summary
     description="Binary Python3 bindings for the G'MIC C++ image processing library",  # Optional
-    # This is an optional longer description of your project that represents
-    # the body of text which users will see when they visit PyPI.
-    #
-    # Often, this is the same as your README, so you can just read it in from
-    # that file directly (as we have already done above)
-    #
-    # This field corresponds to the "Description" metadata field:
-    # https://packaging.python.org/specifications/core-metadata/#description-optional
-    long_description=long_description,  # Optional
-    # Denotes that our long_description is in Markdown; valid values are
-    # text/plain, text/x-rst, and text/markdown
-    #
-    # Optional if long_description is written in reStructuredText (rst) but
-    # required for plain-text or Markdown; if unspecified, "applications should
-    # attempt to render [the long_description] as text/x-rst; charset=UTF-8 and
-    # fall back to text/plain if it is not valid rst" (see link below)
-    #
-    # This field corresponds to the "Description-Content-Type" metadata field:
-    # https://packaging.python.org/specifications/core-metadata/#description-content-type-optional
+    long_description=long_description,
     long_description_content_type="text/markdown",  # Optional (see note above)
-    # This should be a valid link to your project's main homepage.
-    #
-    # This field corresponds to the "Home-Page" metadata field:
-    # https://packaging.python.org/specifications/core-metadata/#home-page-optional
     url="https://github.com/dtschump/gmic-py",  # Optional
-    # This should be your name or the name of the organization which owns the
-    # project.
     author="David Tschumperlé, Jonathan-David Schröder G'MIC GREYC IMAGE Team of CNRS, France",  # Optional
-    # This should be a valid email address corresponding to the author listed
-    # above.
     author_email="David.Tschumperle@ensicaen.fr, jonathan.schroder@gmail.com",  # Optional
-    # Classifiers help users find your project by categorizing it.
-    #
-    # For a list of valid classifiers, see https://pypi.org/classifiers/
     classifiers=[  # Optional
         # How mature is this project? Common values are
         #   3 - Alpha
@@ -215,6 +237,7 @@
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
     ],
     # This field adds keywords for your project which will appear on the
     # project page. What does your project relate to?
@@ -266,9 +289,9 @@
     #
     # If using Python 2.6 or earlier, then these have to be included in
     # MANIFEST.in as well.
-    # package_data={  # Optional
-    #     'sample': ['package_data.dat'],
-    # },
+    package_data=package_data,
+    # include_package_data=True,
+    # data_files=[("", ["COPYING"])],
     # Although 'package_data' is the preferred approach, in some case you may
     # need to place data files outside of your packages. See:
     # http://docs.python.org/3.4/distutils/setupscript.html#installing-additional-files
diff --git a/test-requirements-win.txt b/test-requirements-win.txt
new file mode 100644
index 00000000..779be7cc
--- /dev/null
+++ b/test-requirements-win.txt
@@ -0,0 +1,10 @@
+# For testing, pip install -r dev-requirements.txt first, then this
+
+#scikit-image
+numpy #==1.16.1 # fixes https://github.com/scikit-image/scikit-image/issues/3655
+Pillow
+pytest
+setuptools
+pytest-xdist #allow parallelization
+# psutil # won't compile easily enough on MSYS2 WINDOWS
+# Do not put the 'black' Python code formatter as a dependency here it will not install for Python <= 3.6 and crash the Mac OS CI, black must be installed at formatting check time, outside any docker wheel-building environment. See the related formatting functions in build_tools.bash script.
diff --git a/test-requirements.txt b/test-requirements.txt
new file mode 100644
index 00000000..b47fd3d8
--- /dev/null
+++ b/test-requirements.txt
@@ -0,0 +1,10 @@
+# For testing, pip install -r dev-requirements.txt first, then this
+
+#scikit-image
+numpy #==1.16.1 # fixes https://github.com/scikit-image/scikit-image/issues/3655
+Pillow
+pytest
+setuptools
+pytest-xdist #allow parallelization
+psutil
+# Do not put the 'black' Python code formatter as a dependency here it will not install for Python <= 3.6 and crash the Mac OS CI, black must be installed at formatting check time, outside any docker wheel-building environment. See the related formatting functions in build_tools.bash script.
diff --git a/tests/.gitignore b/tests/.gitignore
index 8e0855fa..297a2419 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -1,2 +1,2 @@
 __pycache__
-*.png
+./*.png
diff --git a/tests/samples/apples.png b/tests/samples/apples.png
new file mode 100644
index 00000000..e678d19f
Binary files /dev/null and b/tests/samples/apples.png differ
diff --git a/tests/samples/duck.png b/tests/samples/duck.png
new file mode 100644
index 00000000..395d07e6
Binary files /dev/null and b/tests/samples/duck.png differ
diff --git a/tests/samples/lena.png b/tests/samples/lena.png
new file mode 100644
index 00000000..93e982bc
Binary files /dev/null and b/tests/samples/lena.png differ
diff --git a/tests/samples/leno.png b/tests/samples/leno.png
new file mode 100644
index 00000000..e0a47b67
Binary files /dev/null and b/tests/samples/leno.png differ
diff --git a/tests/samples/parrots.png b/tests/samples/parrots.png
new file mode 100644
index 00000000..f07c5dbf
Binary files /dev/null and b/tests/samples/parrots.png differ
diff --git a/tests/test_gmic_numpy.py b/tests/test_gmic_numpy.py
index 4b20c7c4..6847fa5c 100644
--- a/tests/test_gmic_numpy.py
+++ b/tests/test_gmic_numpy.py
@@ -74,7 +74,7 @@ def test_gmic_image_to_numpy_ndarray_exception_on_unimportable_numpy_module(
     import gmic
 
     images = []
-    gmic_instance_run(images=images, command="sp duck")
+    gmic_instance_run(images=images, command="tests/samples/duck.png")
     with pytest.raises(
         gmic.GmicException, match=r".*'numpy' module cannot be imported.*"
     ):
@@ -91,7 +91,10 @@ def test_gmic_image_to_numpy_ndarray_exception_on_unimportable_numpy_module(
 @pytest.mark.parametrize(**squeeze_toggles)
 @pytest.mark.parametrize(
     "gmic_command",
-    ["sp apples", """3,5,7,2,'x*cos(0.5236)+y*sin(0.8)' -normalize 0,255"""],
+    [
+        "tests/samples/apples.png",
+        """3,5,7,2,'x*cos(0.5236)+y*sin(0.8)' -normalize 0,255""",
+    ],
     ids=["2dsample", "3dsample"],
 )
 def test_gmic_image_to_numpy_helper_fuzzying(
@@ -162,7 +165,7 @@ def test_gmic_image_to_numpy_ndarray_basic_attributes(gmic_instance_run):
     import numpy
 
     single_image_list = []
-    gmic_instance_run(images=single_image_list, command="sp apples")
+    gmic_instance_run(images=single_image_list, command="tests/samples/apples.png")
     gmic_image = single_image_list[0]
     # we do not interleave to keep the same data structure for later comparison
     numpy_image = gmic_image.to_numpy_helper(interleave=False)
@@ -181,8 +184,8 @@ def test_gmic_image_to_numpy_ndarray_basic_attributes(gmic_instance_run):
 @pytest.mark.parametrize(**gmic_instance_types)
 def test_in_memory_gmic_image_to_numpy_nd_array_to_gmic_image(gmic_instance_run):
     single_image_list = []
-    gmic_instance_run(images=single_image_list, command="sp duck")
-    # TODO convert back and compare with original sp duck GmicImage
+    gmic_instance_run(images=single_image_list, command="tests/samples/duck.png")
+    # TODO convert back and compare with original tests/samples/duck.png GmicImage
 
 
 @pytest.mark.parametrize(**gmic_instance_types)
@@ -195,7 +198,7 @@ def test_numpy_ndarray_RGB_2D_image_gmic_run_without_gmicimage_wrapping(
 
     im1_name = "image.png"
     im2_name = "image.png"
-    gmic_instance_run("sp duck output " + im1_name)
+    gmic_instance_run("tests/samples/duck.png output " + im1_name)
     np_PIL_image = numpy.array(PIL.Image.open(im1_name))
     # TODO line below must fail because single numpy arrays rewrite is impossible for us
     with pytest.raises(
@@ -218,7 +221,7 @@ def test_numpy_ndarray_RGB_2D_image_integrity_through_numpyPIL_or_gmicimage_from
     im2_name = "image2.bmp"
 
     # 1. Generate duck bitmap, save it to disk
-    gmic_instance_run("sp duck -output " + im1_name)
+    gmic_instance_run("tests/samples/duck.png -output " + im1_name)
 
     # 2. Load disk duck through PIL/numpy, make it a GmicImage
     image_from_numpy = numpy.array(PIL.Image.open(im1_name))
@@ -232,7 +235,7 @@ def test_numpy_ndarray_RGB_2D_image_integrity_through_numpyPIL_or_gmicimage_from
 
     # 3. Load duck into a regular GmicImage through G'MIC without PIL/numpy
     imgs = []
-    gmic_instance_run(images=imgs, command="sp duck")
+    gmic_instance_run(images=imgs, command="tests/samples/duck.png")
     gmicimage_from_gmic = imgs[0]
 
     # 4. Use G'MIC to compare both duck GmicImages from numpy and gmic sources
@@ -248,7 +251,7 @@ def test_numpy_PIL_modes_to_gmic(gmic_instance_run):
 
     origin_image_name = "a.bmp"
     gmicimages = []
-    gmic_instance_run("sp duck output " + origin_image_name)
+    gmic_instance_run("tests/samples/duck.png output " + origin_image_name)
     PILimage = PIL.Image.open("a.bmp")
 
     modes = [
@@ -292,7 +295,7 @@ def test_numpy_PIL_modes_to_gmic(gmic_instance_run):
 
 def test_basic_from_numpy_helper_to_numpy_helper():
     duck = []
-    gmic.run("sp duck", duck)
+    gmic.run("tests/samples/duck.png", duck)
     original_duck_gmic_image = duck[0]
     duck_numpy_image = original_duck_gmic_image.to_numpy_helper(squeeze_shape=True)
     duck_io_gmic_image = gmic.GmicImage.from_numpy_helper(duck_numpy_image)
@@ -316,7 +319,7 @@ def test_from_numpy_helper_proper_dimensions_number():
 
 
 def test_basic_to_numpy_helper_from_numpy_helper():
-    gmic.run("sp duck output duck.png")
+    gmic.run("tests/samples/duck.png output duck.png")
     import PIL.Image
 
     pil_image = numpy.array(PIL.Image.open("duck.png"))
diff --git a/tests/test_gmic_numpy_toolkits.py b/tests/test_gmic_numpy_toolkits.py
index 27b235e8..6b674482 100644
--- a/tests/test_gmic_numpy_toolkits.py
+++ b/tests/test_gmic_numpy_toolkits.py
@@ -74,7 +74,7 @@ def numpy_PIL_duck():
     im1_name = "image.bmp"
 
     # 1. Generate duck bitmap, save it to disk
-    gmic.run("sp duck -output " + im1_name)
+    gmic.run("tests/samples/duck.png -output " + im1_name)
 
     # 2. Load disk duck through PIL/numpy, make it a GmicImage
     yield numpy.array(PIL.Image.open(im1_name))
@@ -310,7 +310,7 @@ def test_toolkit_to_PIL():
     l = []
     PIL_leno_filename = "PIL_leno.png"
     PIL_apples_filename = "PIL_apples.png"
-    gmic.run("sp leno sp apples", l)
+    gmic.run("tests/samples/leno.png tests/samples/apples.png", l)
     PIL_leno, PIL_apples = l[0].to_PIL(), l[1].to_PIL()
     PIL_leno.save(PIL_leno_filename, compress_level=0)
     PIL_apples.save(PIL_apples_filename, compress_level=0)
@@ -325,7 +325,7 @@ def test_toolkit_to_PIL():
 def test_toolkit_to_PIL_advanced():
     # to_PIL fine-graining parameters testing
     l = []
-    gmic.run("sp leno sp apples", l)
+    gmic.run("tests/samples/leno.png tests/samples/apples.png", l)
     PIL_leno = l[0].to_PIL(mode="HSV")
     assert PIL_leno.mode == "HSV"
     assert PIL_leno.width == l[0]._width
@@ -342,18 +342,18 @@ def test_toolkit_from_PIL():
     import PIL.Image
 
     l = []
-    gmic.run("sp leno sp apples", l)
+    gmic.run("tests/samples/leno.png tests/samples/apples.png", l)
 
     PIL_apples_filename = "PIL_apples.png"
     PIL_leno_filename = "PIL_leno.png"
 
-    gmic.run("sp leno output " + PIL_leno_filename)
+    gmic.run("tests/samples/leno.png output " + PIL_leno_filename)
     PIL_leno = PIL.Image.open(PIL_leno_filename)
     leno = gmic.GmicImage.from_PIL(PIL_leno)
     assert_gmic_images_are_identical(l[0], leno)
     assert_non_empty_file_exists(PIL_leno_filename).unlink()
 
-    gmic.run("sp apples output " + PIL_apples_filename)
+    gmic.run("tests/samples/apples.png output " + PIL_apples_filename)
     PIL_apples = PIL.Image.open(PIL_apples_filename)
     apples = gmic.GmicImage.from_PIL(PIL_apples)
     assert_gmic_images_are_identical(l[1], apples)
diff --git a/tests/test_gmic_py.py b/tests/test_gmic_py.py
index f5d85aba..be1f659d 100644
--- a/tests/test_gmic_py.py
+++ b/tests/test_gmic_py.py
@@ -73,7 +73,9 @@ def test_run_gmic_ensure_openmp_linked_and_working(capfd, gmic_instance_run):
     import traceback
     import sys
 
-    gmic_instance_run("v - sp lena eval. \"end(run('echo_stdout[] ',merge(t,max)))\"")
+    gmic_instance_run(
+        "v - tests/samples/lena.png eval. \"end(run('echo_stdout[] ',merge(t,max)))\""
+    )
     outerr = capfd.readouterr()
     try:
         assert (
@@ -104,7 +106,7 @@ def test_run_gmic_instance_run_helloworld(capfd, gmic_instance_run):
 def make_sample_format_file(extension):
     filename = "{}_format_io_test.{}".format(extension, extension)
 
-    gmic.run("sp apples output {}".format(filename))
+    gmic.run("tests/samples/apples.png output {}".format(filename))
 
     yield filename
 
@@ -250,7 +252,7 @@ def test_gmic_user_file_autoload_and_use(gmic_instance_run, request, capfd):
             gmic_instance_run = g.run
 
         # 2. Check that our custom command was auto-loaded as expected
-        gmic_instance_run("sp leno " + gmicpy_testing_command)
+        gmic_instance_run("tests/samples/leno.png " + gmicpy_testing_command)
 
 
 @pytest.mark.parametrize(**gmic_instance_types)
@@ -269,9 +271,9 @@ def test_gmic_user_file_explicit_load_and_use(gmic_instance_run, capfd):
                     gmicpy_testing_command
                 ),
             ):
-                gmic_instance_run("sp leno " + gmicpy_testing_command)
+                gmic_instance_run("tests/samples/leno.png " + gmicpy_testing_command)
         else:
-            gmic_instance_run("sp leno " + gmicpy_testing_command)
+            gmic_instance_run("tests/samples/leno.png " + gmicpy_testing_command)
 
 
 # Skipping test per https://github.com/dtschump/gmic/issues/256#issuecomment-694121423
@@ -513,7 +515,7 @@ def assert_gmic_image_is_filled_with(gmic_image, w, h, d, s, pixel_value):
 
 def test_gmic_image_pixel_access():
     images = []
-    gmic.run("sp apples", images)
+    gmic.run("tests/samples/apples.png", images)
     image = images[0]
     assert image(0, 0, 0, 0) == image()
     assert image(s=3) == image(0, 0, 0, 3)
@@ -1070,7 +1072,7 @@ def test_gmic_class_direct_run_remains_usable_instance():
 
 def test_filling_empty_gmicimage_list_with_input_image_nonregtest_issue_30():
     images = []
-    gmic.run(images=images, command="sp lena")
+    gmic.run(images=images, command="tests/samples/lena.png")
     assert len(images) == 1
     assert type(images[0]) == gmic.GmicImage
 
@@ -1078,7 +1080,7 @@ def test_filling_empty_gmicimage_list_with_input_image_nonregtest_issue_30():
 def test_gmic_module_run_vs_single_instance_run_benchmark():
     from time import time
 
-    testing_command = "sp lena blur 10 blur 30 blur 4"
+    testing_command = "tests/samples/lena.png blur 10 blur 30 blur 4"
     testing_iterations_max = 100
     expected_speed_improvement_by_single_instance_runs = 1.1  # at least 10%
 
diff --git a/tests/test_gmic_py_filters_io.py b/tests/test_gmic_py_filters_io.py
index 0568502d..3a04c6af 100644
--- a/tests/test_gmic_py_filters_io.py
+++ b/tests/test_gmic_py_filters_io.py
@@ -305,7 +305,7 @@ def test_gmic_filter_io(filter_inputs, filter_id, filter_params):
         ):
             filter_params[pos] = '"{}"'.format(param.replace('"', '\\"'))
             # One of the worst CLI expression that works thanks to escaping similar to the one below:
-            # gmic sp parrots -srand 781123 fx_watermark_fourier \"\(a\) b\'o\\\"nsoir\",53 output[0]  "/home/jd/Productions/GMIC/gmic-py/build/lib.linux-x86_64-3.7/test-images/fx_watermark_fourier_gmiccli.png"
+            # gmic tests/samples/parrots.png -srand 781123 fx_watermark_fourier \"\(a\) b\'o\\\"nsoir\",53 output[0]  "/home/jd/Productions/GMIC/gmic-py/build/lib.linux-x86_64-3.7/test-images/fx_watermark_fourier_gmiccli.png"
             filter_params_cli[pos] = '\\"{}\\"'.format(
                 param.replace("(", "\\(")
                 .replace(")", "\\)")
diff --git a/tests/test_gmic_py_memfreeing.py b/tests/test_gmic_py_memfreeing.py
index bf6e043c..50b35a1f 100644
--- a/tests/test_gmic_py_memfreeing.py
+++ b/tests/test_gmic_py_memfreeing.py
@@ -1,6 +1,13 @@
 import pytest
 import numpy
-import psutil
+
+try:
+    import psutil
+except:
+    pytest.skip(
+        "psutil not found - this is OK for a mingw environment - see https://github.com/giampaolo/psutil/blob/master/INSTALL.rst#windows",
+        allow_module_level=True,
+    )
 
 import os
 import struct
diff --git a/wheel_repair.py b/wheel_repair.py
new file mode 100644
index 00000000..6f7c6ce8
--- /dev/null
+++ b/wheel_repair.py
@@ -0,0 +1,155 @@
+#!/usr/bin/env python
+
+import os
+import sys
+import shutil
+import hashlib
+import zipfile
+import argparse
+import tempfile
+from collections import defaultdict
+
+import pefile
+from machomachomangler.pe import redll
+
+
+def hash_filename(filepath, blocksize=65536):
+    hasher = hashlib.sha256()
+
+    with open(filepath, "rb") as afile:
+        buf = afile.read(blocksize)
+        while len(buf) > 0:
+            hasher.update(buf)
+            buf = afile.read(blocksize)
+
+    root, ext = os.path.splitext(filepath)
+    return f"{os.path.basename(root)}-{hasher.hexdigest()[:8]}{ext}"
+
+
+def find_dll_dependencies(dll_filepath, vcpkg_bin_dir):
+    pe = pefile.PE(dll_filepath)
+
+    for entry in pe.DIRECTORY_ENTRY_IMPORT:
+        entry_name = entry.dll.decode("utf-8")
+        print("debug: attempting to find", entry, entry.dll, entry.imports, entry.struct, "in", vcpkg_bin_dir)
+        if entry_name in os.listdir(vcpkg_bin_dir):
+            dll_dependencies[os.path.basename(dll_filepath)].add(entry_name)
+            _dll_filepath = os.path.join(vcpkg_bin_dir, entry_name)
+            find_dll_dependencies(_dll_filepath, vcpkg_bin_dir)
+
+
+def mangle_filename(old_filename, new_filename, mapping):
+    with open(old_filename, "rb") as f:
+        buf = f.read()
+
+    try:
+        new_buf = redll(buf, mapping)
+        print("Building mangle filename mapping and redll:", old_filename, new_filename, mapping)
+
+        with open(new_filename, "wb") as f:
+            f.write(new_buf)
+    except ValueError:
+        print("Unsolvable machomangler buffer length error. Skipping mangling of:", old_filename)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description="Vendor in external shared library dependencies of a wheel."
+    )
+    
+    parser.add_argument("WHEEL_FILE", type=str, help="Path to wheel file")
+    parser.add_argument(
+        "-d", "--dll-dir", dest="DLL_DIR", type=str, help="Directory to find the DLLs"
+    )
+    parser.add_argument(
+        "-w",
+        "--wheel-dir",
+        dest="WHEEL_DIR",
+        type=str,
+        help=('Directory to store delocated wheels (default: "wheelhouse/")'),
+        default="wheelhouse/",
+    )
+    
+    args = parser.parse_args()
+    
+    wheel_name = os.path.basename(args.WHEEL_FILE)
+    package_name = wheel_name.split("-")[0]
+    repaired_wheel = os.path.join(args.WHEEL_DIR, wheel_name)
+    
+    old_wheel_dir = tempfile.mkdtemp()
+    new_wheel_dir = tempfile.mkdtemp()
+    
+    with zipfile.ZipFile(args.WHEEL_FILE, "r") as wheel:
+        wheel.extractall(old_wheel_dir)
+        print("showing old_wheel_dir contents")
+        print(os.listdir(old_wheel_dir))
+        print("attempting stat of old_wheel_dir:", old_wheel_dir)
+        os.stat(old_wheel_dir)
+        wheel.extractall(new_wheel_dir)
+        pe_path = list(filter(lambda x: x.endswith((".pyd", ".dll")), wheel.namelist()))[0]
+        print("debug: pe_path is:", pe_path)
+        #tmp_pe_path = os.path.join(old_wheel_dir, package_name, os.path.basename(pe_path))
+        # add dll recursive autodetection
+        tmp_pe_path = os.path.join(old_wheel_dir, os.path.basename(pe_path))
+        print("debug: tmp_pe_path is:", tmp_pe_path)
+    
+    # https://docs.python.org/3/library/platform.html#platform.architecture
+    x = "x64" if sys.maxsize > 2**32 else "x86"
+    # set VCPKG_INSTALLATION_ROOT=C:\dev\vcpkg
+    #dll_dir = os.path.join(os.environ["VCPKG_INSTALLATION_ROOT"], "installed", f"{x}-windows", "bin")
+
+    dll_dir = args.DLL_DIR
+    if not dll_dir and os.environ["VCPKG_INSTALLATION_ROOT"]:
+        # https://docs.python.org/3/library/platform.html#platform.architecture
+        #dll_dir = os.path.join(os.environ["VCPKG_INSTALLATION_ROOT"], "installed", f"{x}-windows", "bin")
+        x = "x64" if sys.maxsize > 2**32 else "x86"
+        # set VCPKG_INSTALLATION_ROOT=C:\dev\vcpkg
+
+    print("debug: dll_dir (lookup directory) is:", dll_dir)
+    
+    dll_dependencies = defaultdict(set)
+    find_dll_dependencies(tmp_pe_path, dll_dir)
+    print("dll_dependencies found:", dll_dependencies)
+
+
+    new_wheel_libs_dir = os.path.join(new_wheel_dir, package_name)
+    os.makedirs(new_wheel_dir, exist_ok=True)
+    
+    for dll, dependencies in dll_dependencies.items():
+        print("about to mangle:", dll)
+        mapping = {}
+    
+        for dep in dependencies:
+            print("about to hash:",os.path.join(dll_dir, dep))
+            hashed_name = hash_filename(os.path.join(dll_dir, dep))  # already basename
+            mapping[dep.encode("ascii")] = hashed_name.encode("ascii")
+            shutil.copy(
+                os.path.join(dll_dir, dep),
+                os.path.join(new_wheel_libs_dir, hashed_name),
+            )
+    
+        if dll == pe_path:
+            # skip mangling module's portable executable itself
+            continue
+        elif dll.endswith(".pyd"):
+            old_name = os.path.join(
+                new_wheel_libs_dir, os.path.basename(tmp_pe_path)
+            )
+            new_name = os.path.join(
+                new_wheel_libs_dir, os.path.basename(tmp_pe_path)
+            )
+        elif dll.endswith(".dll"):
+            old_name = os.path.join(dll_dir, dll)
+            print("about to hash:",os.path.join(dll_dir, dll))
+            hashed_name = hash_filename(os.path.join(dll_dir, dll))  # already basename
+            new_name = os.path.join(new_wheel_libs_dir, hashed_name)
+    
+        mangle_filename(old_name, new_name, mapping)
+    
+    with zipfile.ZipFile(repaired_wheel, "w", zipfile.ZIP_DEFLATED) as new_wheel:
+        for root, dirs, files in os.walk(new_wheel_dir):
+            for file in files:
+                print("new wheel copying:", os.path.join(root, file), os.path.join(os.path.basename(root), file))
+                new_wheel.write(
+                    os.path.join(root, file), os.path.join(os.path.basename(root), file)
+                )
diff --git a/win_dll/.gitignore b/win_dll/.gitignore
new file mode 100644
index 00000000..e69de29b