feat: 切换后端至PaddleOCR-NCNN，切换工程为CMake

1.项目后端整体迁移至PaddleOCR-NCNN算法，已通过基本的兼容性测试
2.工程改为使用CMake组织，后续为了更好地兼容第三方库，不再提供QMake工程
3.重整权利声明文件，重整代码工程，确保最小化侵权风险

Log: 切换后端至PaddleOCR-NCNN，切换工程为CMake
Change-Id: I4d5d2c5d37505a4a24b389b1a4c5d12f17bfa38c

3rdparty/opencv-4.5.4/modules/highgui/src/backend.cpp

@@ -0,0 +1,181 @@
+// 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.
+#include "precomp.hpp"
+#include "backend.hpp"
+
+#include <opencv2/core/utils/configuration.private.hpp>
+#include <opencv2/core/utils/logger.defines.hpp>
+#ifdef NDEBUG
+#define CV_LOG_STRIP_LEVEL CV_LOG_LEVEL_DEBUG + 1
+#else
+#define CV_LOG_STRIP_LEVEL CV_LOG_LEVEL_VERBOSE + 1
+#endif
+#include <opencv2/core/utils/logger.hpp>
+
+
+#include "registry.hpp"
+#include "registry.impl.hpp"
+
+#include "plugin_api.hpp"
+#include "plugin_wrapper.impl.hpp"
+
+
+namespace cv { namespace highgui_backend {
+
+UIBackend::~UIBackend()
+{
+    // nothing
+}
+
+UIWindowBase::~UIWindowBase()
+{
+    // nothing
+}
+
+UIWindow::~UIWindow()
+{
+    // nothing
+}
+
+UITrackbar::~UITrackbar()
+{
+    // nothing
+}
+
+static
+std::string& getUIBackendName()
+{
+    static std::string g_backendName = toUpperCase(cv::utils::getConfigurationParameterString("OPENCV_UI_BACKEND", ""));
+    return g_backendName;
+}
+
+static bool g_initializedUIBackend = false;
+
+static
+std::shared_ptr<UIBackend> createUIBackend()
+{
+    const std::string& name = getUIBackendName();
+    bool isKnown = false;
+    const auto& backends = getBackendsInfo();
+    if (!name.empty())
+    {
+        CV_LOG_INFO(NULL, "UI: requested backend name: " << name);
+    }
+    for (size_t i = 0; i < backends.size(); i++)
+    {
+        const auto& info = backends[i];
+        if (!name.empty())
+        {
+            if (name != info.name)
+            {
+                continue;
+            }
+            isKnown = true;
+        }
+        try
+        {
+            CV_LOG_DEBUG(NULL, "UI: trying backend: " << info.name << " (priority=" << info.priority << ")");
+            if (!info.backendFactory)
+            {
+                CV_LOG_DEBUG(NULL, "UI: factory is not available (plugins require filesystem support): " << info.name);
+                continue;
+            }
+            std::shared_ptr<UIBackend> backend = info.backendFactory->create();
+            if (!backend)
+            {
+                CV_LOG_VERBOSE(NULL, 0, "UI: not available: " << info.name);
+                continue;
+            }
+            CV_LOG_INFO(NULL, "UI: using backend: " << info.name << " (priority=" << info.priority << ")");
+            g_initializedUIBackend = true;
+            getUIBackendName() = info.name;
+            return backend;
+        }
+        catch (const std::exception& e)
+        {
+            CV_LOG_WARNING(NULL, "UI: can't initialize " << info.name << " backend: " << e.what());
+        }
+        catch (...)
+        {
+            CV_LOG_WARNING(NULL, "UI: can't initialize " << info.name << " backend: Unknown C++ exception");
+        }
+    }
+    if (name.empty())
+    {
+        CV_LOG_DEBUG(NULL, "UI: fallback on builtin code: " OPENCV_HIGHGUI_BUILTIN_BACKEND_STR);
+    }
+    else
+    {
+        if (!isKnown)
+            CV_LOG_INFO(NULL, "UI: unknown backend: " << name);
+    }
+    g_initializedUIBackend = true;
+    return std::shared_ptr<UIBackend>();
+}
+
+static inline
+std::shared_ptr<UIBackend> createDefaultUIBackend()
+{
+    CV_LOG_DEBUG(NULL, "UI: Initializing backend...");
+    return createUIBackend();
+}
+
+std::shared_ptr<UIBackend>& getCurrentUIBackend()
+{
+    static std::shared_ptr<UIBackend> g_currentUIBackend = createDefaultUIBackend();
+    return g_currentUIBackend;
+}
+
+void setUIBackend(const std::shared_ptr<UIBackend>& api)
+{
+    getCurrentUIBackend() = api;
+}
+
+bool setUIBackend(const std::string& backendName)
+{
+    CV_TRACE_FUNCTION();
+
+    std::string backendName_u = toUpperCase(backendName);
+    if (g_initializedUIBackend)
+    {
+        // ... already initialized
+        if (getUIBackendName() == backendName_u)
+        {
+            CV_LOG_INFO(NULL, "UI: backend is already activated: " << (backendName.empty() ? "builtin(legacy)" : backendName));
+            return true;
+        }
+        else
+        {
+            // ... re-create new
+            CV_LOG_DEBUG(NULL, "UI: replacing backend...");
+            getUIBackendName() = backendName_u;
+            getCurrentUIBackend() = createUIBackend();
+        }
+    }
+    else
+    {
+        // ... no backend exists, just specify the name (initialization is triggered by getCurrentUIBackend() call)
+        getUIBackendName() = backendName_u;
+    }
+    std::shared_ptr<UIBackend> api = getCurrentUIBackend();
+    if (!api)
+    {
+        if (!backendName.empty())
+        {
+            CV_LOG_WARNING(NULL, "UI: backend is not available: " << backendName << " (using builtin legacy code)");
+            return false;
+        }
+        else
+        {
+            CV_LOG_WARNING(NULL, "UI: switched to builtin code (legacy)");
+        }
+    }
+    if (!backendName_u.empty())
+    {
+        CV_Assert(backendName_u == getUIBackendName());  // data race?
+    }
+    return true;
+}
+
+}}  // namespace cv::highgui_backend

3rdparty/opencv-4.5.4/modules/highgui/src/backend.hpp

@@ -0,0 +1,135 @@
+// 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_HIGHGUI_BACKEND_HPP
+#define OPENCV_HIGHGUI_BACKEND_HPP
+
+#include <memory>
+#include <map>
+
+namespace cv { namespace highgui_backend {
+
+class CV_EXPORTS UIWindowBase
+{
+public:
+    typedef std::shared_ptr<UIWindowBase> Ptr;
+    typedef std::weak_ptr<UIWindowBase> WeakPtr;
+
+    virtual ~UIWindowBase();
+
+    virtual const std::string& getID() const = 0;  // internal name, used for logging
+
+    virtual bool isActive() const = 0;
+
+    virtual void destroy() = 0;
+};  // UIWindowBase
+
+class UITrackbar;
+
+class CV_EXPORTS UIWindow : public UIWindowBase
+{
+public:
+    virtual ~UIWindow();
+
+    virtual void imshow(InputArray image) = 0;
+
+    virtual double getProperty(int prop) const = 0;
+    virtual bool setProperty(int prop, double value) = 0;
+
+    virtual void resize(int width, int height) = 0;
+    virtual void move(int x, int y) = 0;
+
+    virtual Rect getImageRect() const = 0;
+
+    virtual void setTitle(const std::string& title) = 0;
+
+    virtual void setMouseCallback(MouseCallback onMouse, void* userdata /*= 0*/) = 0;
+
+    //TODO: handle both keys and mouse events (both with mouse coordinates)
+    //virtual void setInputCallback(InputCallback onInputEvent, void* userdata /*= 0*/) = 0;
+
+    virtual std::shared_ptr<UITrackbar> createTrackbar(
+        const std::string& name,
+        int count,
+        TrackbarCallback onChange /*= 0*/,
+        void* userdata /*= 0*/
+    ) = 0;
+
+    virtual std::shared_ptr<UITrackbar> findTrackbar(const std::string& name) = 0;
+
+#if 0  // QT only
+    virtual void displayOverlay(const std::string& text, int delayms = 0) = 0;
+    virtual void displayStatusBar(const std::string& text, int delayms /*= 0*/) = 0;
+    virtual int createButton(
+        const std::string& bar_name, ButtonCallback on_change,
+        void* userdata = 0, int type /*= QT_PUSH_BUTTON*/,
+        bool initial_button_state /*= false*/
+    ) = 0;
+    // addText, QtFont stuff
+#endif
+
+#if 0  // OpenGL
+    virtual void imshow(const ogl::Texture2D& tex) = 0;
+    virtual void setOpenGlDrawCallback(OpenGlDrawCallback onOpenGlDraw, void* userdata = 0) = 0;
+    virtual void setOpenGlContext() = 0;
+    virtual void updateWindow() = 0;
+#endif
+
+};  // UIWindow
+
+
+class CV_EXPORTS UITrackbar : public UIWindowBase
+{
+public:
+    virtual ~UITrackbar();
+
+    virtual int getPos() const = 0;
+    virtual void setPos(int pos) = 0;
+
+    virtual cv::Range getRange() const = 0;
+    virtual void setRange(const cv::Range& range) = 0;
+};  // UITrackbar
+
+
+class CV_EXPORTS UIBackend
+{
+public:
+    virtual ~UIBackend();
+
+    virtual void destroyAllWindows() = 0;
+
+    // namedWindow
+    virtual std::shared_ptr<UIWindow> createWindow(
+        const std::string& winname,
+        int flags
+    ) = 0;
+
+    virtual int waitKeyEx(int delay /*= 0*/) = 0;
+    virtual int pollKey() = 0;
+};
+
+std::shared_ptr<UIBackend>& getCurrentUIBackend();
+void setUIBackend(const std::shared_ptr<UIBackend>& api);
+bool setUIBackend(const std::string& backendName);
+
+#ifndef BUILD_PLUGIN
+
+#ifdef HAVE_WIN32UI
+std::shared_ptr<UIBackend> createUIBackendWin32UI();
+#endif
+
+#ifdef HAVE_GTK
+std::shared_ptr<UIBackend> createUIBackendGTK();
+#endif
+
+#if 0  // TODO: defined HAVE_QT
+std::shared_ptr<UIBackend> createUIBackendQT();
+#endif
+
+#endif  // BUILD_PLUGIN
+
+}  // namespace highgui_backend
+
+}  // namespace cv
+
+#endif // OPENCV_HIGHGUI_BACKEND_HPP

3rdparty/opencv-4.5.4/modules/highgui/src/factory.hpp

@@ -0,0 +1,48 @@
+// 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_UI_FACTORY_HPP
+#define OPENCV_UI_FACTORY_HPP
+
+#include "backend.hpp"
+
+namespace cv { namespace highgui_backend {
+
+class IUIBackendFactory
+{
+public:
+    virtual ~IUIBackendFactory() {}
+    virtual std::shared_ptr<cv::highgui_backend::UIBackend> create() const = 0;
+};
+
+
+class StaticBackendFactory CV_FINAL: public IUIBackendFactory
+{
+protected:
+    std::function<std::shared_ptr<cv::highgui_backend::UIBackend>(void)> create_fn_;
+
+public:
+    StaticBackendFactory(std::function<std::shared_ptr<cv::highgui_backend::UIBackend>(void)>&& create_fn)
+        : create_fn_(create_fn)
+    {
+        // nothing
+    }
+
+    ~StaticBackendFactory() CV_OVERRIDE {}
+
+    std::shared_ptr<cv::highgui_backend::UIBackend> create() const CV_OVERRIDE
+    {
+        return create_fn_();
+    }
+};
+
+//
+// PluginUIBackendFactory is implemented in plugin_wrapper
+//
+
+std::shared_ptr<IUIBackendFactory> createPluginUIBackendFactory(const std::string& baseName);
+
+}}  // namespace
+
+#endif  // OPENCV_UI_FACTORY_HPP