Camera and Camera2 preview is rendered via OpenGL textures and can be modified on CPU via C++ code. No OpenCL yet.

samples/android/tutorial-4-opencl/CMakeLists.txt

@@ -0,0 +1,12 @@
+set(sample example-tutorial-4-opencl)
+
+if(BUILD_FAT_JAVA_LIB)
+  set(native_deps opencv_java)
+else()
+  set(native_deps opencv_imgproc)
+endif()
+
+add_android_project(${sample} "${CMAKE_CURRENT_SOURCE_DIR}" LIBRARY_DEPS ${OpenCV_BINARY_DIR} SDK_TARGET 21 ${ANDROID_SDK_TARGET} NATIVE_DEPS ${native_deps})
+if(TARGET ${sample})
+  add_dependencies(opencv_android_examples ${sample})
+endif()