Support Ascend NPU

Ascend NPU is a series of AI processors.
[hiascend](https://www.hiascend.com/).

This commit provides support for Ascend NPU as a compute accelerator. As
the first commit for Ascend NPU, this commit only provides very limited
opeartors, but make it possible to add more operators in a short
time.

Asynchronous operation call and python interface are also supported.

modules/cannarithm/CMakeLists.txt

@@ -0,0 +1,16 @@
+ if(IOS OR WINRT OR ANDROID OR APPLE OR WIN32 OR (NOT HAVE_CANN))
+   ocv_module_disable(cannarithm)
+ endif()
+
+set(the_description "Ascend-accelerated Operations on Matrices")
+
+ocv_add_module(cannarithm opencv_core WRAP python)
+ocv_module_include_directories(${CANN_INCLUDE_DIRS})
+ocv_glob_module_sources()
+ocv_install_used_external_targets(${CANN_LIBRARIES})
+ocv_create_module(${CANN_LIBRARIES})
+
+ocv_include_directories(${CMAKE_SOURCE_DIR}/modules/ts/include)
+
+ocv_add_accuracy_tests(DEPENDS_ON opencv_cannarithm)
+#ocv_add_perf_tests(DEPENDS_ON opencv_cannarithm)

modules/cannarithm/include/opencv2/acl_stream_accessor.hpp

@@ -0,0 +1,40 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+
+#ifndef OPENCV_CANN_STREAM_ACCESSOR_HPP
+#define OPENCV_CANN_STREAM_ACCESSOR_HPP
+
+#include <acl/acl.h>
+#include "opencv2/cann.hpp"
+
+namespace cv
+{
+namespace cann
+{
+
+//! @addtogroup cann_struct
+//! @{
+
+/** @brief Class that enables getting aclrtAclStream from cann::AclStream
+ */
+struct AclStreamAccessor
+{
+    CV_EXPORTS static aclrtStream getStream(const AclStream& stream);
+    CV_EXPORTS static AclStream wrapStream(aclrtStream stream);
+};
+
+/** @brief Class that enables getting aclrtAclEvent from cann::AclEvent
+ */
+struct AclEventAccessor
+{
+    CV_EXPORTS static aclrtEvent getEvent(const AclEvent& event);
+    CV_EXPORTS static AclEvent wrapEvent(aclrtEvent event);
+};
+
+//! @} cann_struct
+
+} // namespace cann
+} // namespace cv
+
+#endif // OPENCV_CANN_STREAM_ACCESSOR_HPP

modules/cannarithm/include/opencv2/cann.hpp

@@ -0,0 +1,335 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+
+#ifndef OPENCV_CANN_HPP
+#define OPENCV_CANN_HPP
+
+#include "opencv2/core.hpp"
+
+/**
+  @defgroup cann Ascend-accelerated Computer Vision
+  @{
+    @defgroup canncore Core part
+    @{
+      @defgroup cann_struct Data Structures
+      @defgroup cann_init Initializeation and Information
+    @}
+  @}
+ */
+
+namespace cv
+{
+namespace cann
+{
+class AclStream;
+
+//! @addtogroup cann_struct
+//! @{
+
+//===================================================================================
+// AclMat
+//===================================================================================
+
+/** @brief Base storage class for NPU memory with reference counting.
+ * AclMat class has a similar interface with Mat and AclMat, and work on [Ascend
+ * NPU](https://www.hiascend.com/) backend.
+ * @sa Mat cuda::GpuMat
+ */
+
+class CV_EXPORTS_W AclMat
+{
+public:
+    class CV_EXPORTS_W Allocator
+    {
+    public:
+        virtual ~Allocator() {}
+
+        // allocator must fill data, step and refcount fields
+        virtual bool allocate(AclMat* mat, int rows, int cols, size_t elemSize) = 0;
+        virtual void free(AclMat* mat) = 0;
+    };
+
+    /**
+     * @brief Create default allocator for AclMat. This allocator alloc memory from device for
+     * specific size.
+     */
+    CV_WRAP static AclMat::Allocator* defaultAllocator();
+
+    /**
+     * @brief Set allocator for AclMat.
+     * @param allocator
+     */
+    CV_WRAP static void setDefaultAllocator(AclMat::Allocator* allocator);
+
+    //! default constructor
+    CV_WRAP explicit AclMat(AclMat::Allocator* allocator_ = AclMat::defaultAllocator());
+
+    //! constructs AclMat of the specified size and type
+    CV_WRAP AclMat(int rows, int cols, int type,
+                   AclMat::Allocator* allocator = AclMat::defaultAllocator());
+    //! constructs AclMat of the specified size and type
+    CV_WRAP AclMat(Size size, int type, AclMat::Allocator* allocator = AclMat::defaultAllocator());
+
+    //! constructs AclMat and fills it with the specified value s
+    CV_WRAP AclMat(int rows, int cols, int type, Scalar& s,
+                   AclMat::Allocator* allocator = AclMat::defaultAllocator());
+    //! constructs AclMat and fills it with the specified value s
+    CV_WRAP AclMat(Size size, int type, Scalar& s,
+                   AclMat::Allocator* allocator = AclMat::defaultAllocator());
+
+    //! copy constructor
+    CV_WRAP AclMat(const AclMat& m);
+
+    //! constructor for AclMat headers pointing to user-allocated data
+    AclMat(int rows, int cols, int type, void* data, size_t step = Mat::AUTO_STEP);
+    //! constructor for AclMat headers pointing to user-allocated data
+    AclMat(Size size, int type, void* data, size_t step = Mat::AUTO_STEP);
+
+    //! builds AclMat from host memory (Blocking call)
+    CV_WRAP explicit AclMat(InputArray arr,
+                            AclMat::Allocator* allocator = AclMat::defaultAllocator());
+
+    //! assignment operators
+    AclMat& operator=(const AclMat& m);
+
+    //! destructor - calls release()
+    ~AclMat();
+
+    //! sets some of the AclMat elements to s (Blocking call)
+    CV_WRAP AclMat& setTo(Scalar s);
+    //! sets some of the AclMat elements to s (Non-Blocking call)
+    CV_WRAP AclMat& setTo(Scalar s, AclStream& stream);
+
+    //! swaps with other smart pointer
+    CV_WRAP void swap(AclMat& mat);
+
+    //! allocates new AclMat data unless the AclMat already has specified size and type
+    CV_WRAP void create(int rows, int cols, int type);
+
+    //! upload host memory data to AclMat (Blocking call)
+    CV_WRAP void upload(InputArray arr);
+    //! upload host memory data to AclMat (Non-Blocking call)
+    CV_WRAP void upload(InputArray arr, AclStream& stream);
+
+    //! download data from AclMat to host (Blocking call)
+    CV_WRAP void download(OutputArray dst) const;
+    //! download data from AclMat to host (Non-Blocking call)
+    CV_WRAP void download(OutputArray dst, AclStream& stream) const;
+
+    //! converts AclMat to another datatype (Blocking call)
+    CV_WRAP void convertTo(CV_OUT AclMat& dst, int rtype) const;
+
+    //! converts AclMat to another datatype (Non-Blocking call)
+    CV_WRAP void convertTo(CV_OUT AclMat& dst, int rtype, AclStream& stream) const;
+
+    //! decreases reference counter, deallocate the data when reference counter reaches 0
+    CV_WRAP void release();
+
+    //! returns element size in bytes
+    CV_WRAP size_t elemSize() const;
+
+    //! returns the size of element channel in bytes
+    CV_WRAP size_t elemSize1() const;
+
+    //! returns element type
+    CV_WRAP int type() const;
+
+    //! returns element type
+    CV_WRAP int depth() const;
+
+    //! returns number of channels
+    CV_WRAP int channels() const;
+
+    //! returns step/elemSize1()
+    CV_WRAP size_t step1() const;
+
+    //! returns AclMat size : width == number of columns, height == number of rows
+    CV_WRAP Size size() const;
+
+    //! returns true if AclMat data is NULL
+    CV_WRAP bool empty() const;
+
+    //! internal use method: updates the continuity flag
+    CV_WRAP void updateContinuityFlag();
+
+    //! expand one channel mat to multi-channels (Blocking call)
+    //! @note, source mat must only have one channel, copy value to all channels.
+    CV_WRAP void expandTo(CV_OUT AclMat& dst, int channels) const;
+
+    //! expand one channel mat to multi-channels (Non-Blocking call)
+    //! @note, source mat must only have one channel, copy value to all channels.
+    CV_WRAP void expandTo(CV_OUT AclMat& dst, int channels, AclStream& stream) const;
+
+    /*! includes several bit-fields:
+     - the magic signature
+     - continuity flag
+     - depth
+     - number of channels
+     */
+    int flags;
+
+    //! the number of rows and columns
+    int rows, cols;
+
+    //! a distance between successive rows in bytes; includes the gap if any
+    CV_PROP size_t step;
+
+    //! pointer to the data
+    uchar* data;
+
+    //! pointer to the reference counter;
+    //! when AclMat points to user-allocated data, the pointer is NULL
+    int* refcount;
+
+    //! helper fields used in locateROI and adjustROI
+    uchar* datastart;
+    const uchar* dataend;
+
+    //! allocator
+    Allocator* allocator;
+};
+
+class AclStream;
+class AclStreamAccessor;
+class AclEvent;
+class AclEventAccessor;
+class DefaultDeviceInitializer;
+
+//===================================================================================
+// AclStream
+//===================================================================================
+
+/** @brief In AscendCL Stream(AclStream) is a task queue. Stream is used to manage the parallelism
+ * of tasks. The tasks inside a Stream are executed sequentially, that is, the Stream executes
+ * sequentially according to the sent tasks; the tasks in different Streams are executed in
+ * parallel.
+ *
+ * All Non-blocking functions should pass parameter stream, These function returns immediately after
+ * the task is submitted. Caller should wait stream until completion.
+ *
+ * Blocking functions implicityly use the default stream, and synchronize stream before function
+ * return.
+ * @sa cuda::Stream
+ */
+
+// TODO: Stream is defined in namespace cuda, and pybind code does not use a namespace of stream,
+// change stream name to AclStream to avoid confilct.
+class CV_EXPORTS_W AclStream
+{
+public:
+    CV_WRAP AclStream();
+
+    //! blocks the current CPU thread until all operations in the stream are complete.
+    CV_WRAP void waitForCompletion();
+
+    //! blocks the current CPU thread until event trigger.
+    CV_WRAP void waitAclEvent(const cv::cann::AclEvent& event);
+
+    /**
+     * @brief return default AclStream object for default Acl stream.
+     */
+    CV_WRAP static AclStream& Null();
+
+    // acl symbols CANNOT used in any hpp files. Use a inner class to avoid acl symbols defined in
+    // hpp.
+    class Impl;
+
+    // add temporary mat for async release.
+    void addToAsyncRelease(const AclMat& mat);
+
+private:
+    Ptr<Impl> impl_;
+    AclStream(const Ptr<Impl>& impl);
+
+    friend class AclStreamAccessor;
+    friend class DefaultDeviceInitializer;
+};
+
+/**
+ * @brief AclEvent to synchronize between different streams.
+ */
+class CV_EXPORTS_W AclEvent
+{
+public:
+    CV_WRAP AclEvent();
+
+    //! records an event
+    CV_WRAP void record(AclStream& stream = AclStream::Null());
+
+    //! waits for an event to complete
+    CV_WRAP void waitForComplete() const;
+
+    class Impl;
+
+private:
+    Ptr<Impl> impl_;
+    AclEvent(const Ptr<Impl>& impl);
+
+    friend class AclEventAccessor;
+};
+
+/** @brief Bindings overload to create a Stream object from the address stored in an existing CANN
+ * Runtime API stream pointer (aclrtStream).
+ * @param aclStreamAddress Memory address stored in a CANN Runtime API stream pointer
+ * (aclrtStream). The created Stream object does not perform any allocation or deallocation and simply
+ * wraps existing raw CANN Runtime API stream pointer.
+ * @note Overload for generation of bindings only, not exported or intended for use internally fro C++.
+ */
+CV_EXPORTS_W AclStream wrapStream(size_t aclStreamAddress);
+
+//! @} cann_struct
+
+//===================================================================================
+// Initialization & Info
+//===================================================================================
+
+//! @addtogroup cann_init
+//! @{
+
+//! Get Ascend matrix object from Input array, upload matrix memory if need. (Blocking call)
+AclMat getInputMat(InputArray src);
+//! Get Ascend matrix object from Input array, upload matrix memory if need. (Non-Blocking call)
+AclMat getInputMat(InputArray src, AclStream& stream);
+
+//! Get Ascend matrix object from Output array, upload matrix memory if need.
+AclMat getOutputMat(OutputArray dst, int rows, int cols, int type);
+
+//! Sync output matrix to Output array, download matrix memory if need.
+void syncOutput(const AclMat& dst, OutputArray _dst);
+
+/**
+ * @brief Choose Ascend npu device.
+ */
+CV_EXPORTS_W void setDevice(int device);
+
+/**
+ * @brief Clear all context created in current Ascend device.
+ */
+CV_EXPORTS_W void resetDevice();
+
+/**
+ * @brief Get current Ascend device.
+ */
+CV_EXPORTS_W int32_t getDevice();
+
+/**
+ * @brief init AscendCL.
+ */
+CV_EXPORTS_W void initAcl();
+
+/**
+ * @brief finalize AscendCL.
+ * @note finalizeAcl only can be called once for a process. Call this function after all AscendCL
+ * options finished.
+ */
+CV_EXPORTS_W void finalizeAcl();
+
+//! @} cann_init
+
+} // namespace cann
+} // namespace cv
+
+#include "opencv2/cann.inl.hpp"
+
+#endif /* OPENCV_CANN_HPP */