diff --git a/README.md b/README.md
index a46a0e0..69c6076 100644
--- a/README.md
+++ b/README.md
@@ -305,6 +305,12 @@ if(ESP32)
 endif()
 ```
 
+The checks for system libraries (`libpthread`, `libdl`, `libm`, `librt`) are also activated by changing the line 607 of the `CMakeList.txt` file:
+
+```cmake
+if(UNIX OF ESP32)
+```
+
 
 
 The `cmake` command is run, leading to the following errors:
@@ -512,7 +518,17 @@ The library is compiled in the `3rdparty/` folder. Copy this folder into the esp
 
 ## Adding parallel support
 
-TODO
+To add loop parallelization on the 2 cores of the esp32, the following modifications are done:
+
+* Changed cmake command with `-DWITH_PTHREADS_PF=ON` 
+* Had to temporary add a pthread_cond usage in the main component for the link to work (otherwise had an *undefined reference to pthread_cond_* functions)
+  * The pthread_cond implementation is in the esp-idf pthread component. Haven't found yet how to link it 
+* In `parallel.cpp` function `getNumberOfCPUs`: 
+  * For now, couldn't make `sysconf` function to work (to get the number of cpus), so returns 2 if ESP32 is defined
+* In idf menuconfig: 
+  * set pthread default stack size to 8192
+
+These modifications haven't improved the performances on the benchmark for now.
 
 
 
diff --git a/esp32/lib/opencv/3rdparty/liblibpng.a b/esp32/lib/opencv/3rdparty/liblibpng.a
index 3b4a228..bbd0e26 100644
Binary files a/esp32/lib/opencv/3rdparty/liblibpng.a and b/esp32/lib/opencv/3rdparty/liblibpng.a differ
diff --git a/esp32/lib/opencv/3rdparty/libzlib.a b/esp32/lib/opencv/3rdparty/libzlib.a
index 3694252..b72351d 100644
Binary files a/esp32/lib/opencv/3rdparty/libzlib.a and b/esp32/lib/opencv/3rdparty/libzlib.a differ
diff --git a/esp32/lib/opencv/libade.a b/esp32/lib/opencv/libade.a
index 71e9cb7..de34352 100644
Binary files a/esp32/lib/opencv/libade.a and b/esp32/lib/opencv/libade.a differ
diff --git a/esp32/lib/opencv/libopencv_core.a b/esp32/lib/opencv/libopencv_core.a
index bbc433c..e935268 100644
Binary files a/esp32/lib/opencv/libopencv_core.a and b/esp32/lib/opencv/libopencv_core.a differ
diff --git a/esp32/lib/opencv/libopencv_imgcodecs.a b/esp32/lib/opencv/libopencv_imgcodecs.a
index ed1ae7e..f27a787 100644
Binary files a/esp32/lib/opencv/libopencv_imgcodecs.a and b/esp32/lib/opencv/libopencv_imgcodecs.a differ
diff --git a/esp32/lib/opencv/libopencv_imgproc.a b/esp32/lib/opencv/libopencv_imgproc.a
index 4e00c01..8822f40 100644
Binary files a/esp32/lib/opencv/libopencv_imgproc.a and b/esp32/lib/opencv/libopencv_imgproc.a differ
diff --git a/modules/core/src/parallel.cpp b/modules/core/src/parallel.cpp
index dd477a1..2929ffb 100644
--- a/modules/core/src/parallel.cpp
+++ b/modules/core/src/parallel.cpp
@@ -950,6 +950,10 @@ int cv::getNumberOfCPUs(void)
 
 #endif
 
+#if defined(ESP32)
+    ncpus = 2;      // TODO: Only for ESP32D0WD
+#endif
+
     return ncpus != 0 ? ncpus : 1;
 }
 
diff --git a/modules/core/src/parallel_impl.cpp b/modules/core/src/parallel_impl.cpp
index 958d7cd..fde8ccf 100644
--- a/modules/core/src/parallel_impl.cpp
+++ b/modules/core/src/parallel_impl.cpp
@@ -7,13 +7,7 @@
 #include "parallel_impl.hpp"
 
 #ifdef HAVE_PTHREADS_PF
-#ifdef __cplusplus
-extern "C" {
-#endif
 #include <pthread.h>
-#ifdef __cplusplus
-}
-#endif
 
 #include <opencv2/core/utils/configuration.private.hpp>