c – 使用python中的Opencv Cuda函数

对于我的一个课程项目,我需要使用OpenCVs GPU库.我正在使用OpenCV python的现有代码,我的工作是找到一种方法来访问OpenCV Cuda库,因为现在没有可访问的 Python绑定到OpenCV的各种CUDA模块.

我现在非常需要的两个函数是cuda :: warpPerspective和cv :: cuda :: DescriptorMatcher :: knnMatch().

我试图按照@ostrumvulpes在Accessing OpenCV CUDA Functions from Python (No PyCUDA)中提出的建议来实现warpPerspective并且它工作正常.现在我被困在DescriptorMatcher :: knnMatch()中.更确切地说,我需要使用蛮力描述符匹配器knnmatch函数(CUDA).我在网上搜索了用C编写的例子,这样我就可以初步了解如何通过cython将其转换为使其工作.

我发现的大多数例子如下：

Ptr<cuda::DescriptorMatcher> matcher = 
cuda::DescriptorMatcher::createBFMatcher();
vector< vector< DMatch> > matches;
matcher->knnMatch(descriptors_object_Gpu,descriptors_scene_Gpu,matches,2);

为了实现这三行,我首先在.pxd文件中添加了我认为必要的内容.我的pxd文件如下所示：

GpuWrapper.pxd

from libcpp cimport bool
from cpython.ref cimport PyObject
from libcpp.vector cimport vector

# References PyObject to OpenCV object conversion code borrowed from OpenCV's own conversion file,cv2.cpp
cdef extern from 'pyopencv_converter.cpp':
    #mrc689 April 20,2017
    void import_array()
    cdef PyObject* pyopencv_from(const Mat& m)
    cdef bool pyopencv_to(PyObject* o,Mat& m)

cdef extern from 'opencv2/imgproc.hpp' namespace 'cv':
    cdef enum InterpolationFlags:
        INTER_NEAREST = 0
    cdef enum ColorConversionCodes:
        COLOR_BGR2GRAY

cdef extern from 'opencv2/core/core.hpp':
    cdef int CV_8UC1
    cdef int CV_32FC1

cdef extern from 'opencv2/core/core.hpp' namespace 'cv':
    cdef cppclass Size_[T]:
        Size_() except +
        Size_(T width,T height) except +
        T width
        T height
    ctypedef Size_[int] Size2i
    ctypedef Size2i Size
    cdef cppclass Scalar[T]:
        Scalar() except +
        Scalar(T v0) except +

cdef extern from 'opencv2/core/core.hpp' namespace 'cv':
    cdef cppclass Mat:
        Mat() except +
        void create(int,int,int) except +
        void* data
        int rows
        int cols

    #added to test the Algorithm class inside core.hpp on May5th 12.52 AM.
    cdef cppclass Algorithm:
        Algorithm() except +

cdef extern from 'opencv2/core/base.hpp' namespace 'cv':
    cdef enum NormTypes:
        NORM_INF= 1,NORM_L1= 2,NORM_L2= 4,NORM_HAMMING= 6,NORM_HAMMING2= 7,cdef extern from 'opencv2/core/cuda.hpp' namespace 'cv::cuda':
    cdef cppclass GpuMat:
        GpuMat() except +
        void upload(Mat arr) except +
        void download(Mat dst) const
    cdef cppclass Stream:
        Stream() except +

cdef extern from 'opencv2/core/types.hpp' namespace 'cv':
    cdef cppclass DMatch:
        DMatch() except +
        float distance
        int imgIdx
        int queryIdx
        int trainIdx

cdef extern from 'opencv2/core/cvstd.hpp' namespace 'cv':
    cdef cppclass Ptr[T]:
        T element_type
        Ptr() except +   


cdef extern from 'opencv2/cudafeatures2d.hpp' namespace 'cv::cuda':
    cdef cppclass DescriptorMatcher:
        @staticmethod
        Ptr[DescriptorMatcher] createBFMatcher(int normType) except+
        #Expected to see error here
        void knnMatch(GpuMat queryDescriptors,GpuMat trainDescriptors,vector[vector[DMatch]] &matches,int k)

cdef extern from 'opencv2/cudawarping.hpp' namespace 'cv::cuda':
    cdef void warpPerspective(GpuMat src,GpuMat dst,Mat M,Size dsize,int flags,int borderMode,Scalar borderValue,Stream& stream)
    # Function using default values
    cdef void warpPerspective(GpuMat src,int flags)

我的pyx看起来像这样：

GpuWrapper.pyx

import numpy as np  # Import Python functions,attributes,submodules of numpy
cimport numpy as np  # Import numpy C/C++ API

def match_feature(np.ndarray[np.float32_t,ndim=3] _src,np.ndarray[np.float32_t,ndim=2] _M):

    np.import_array()
    # Create GPU/device InputArray for src
    cdef Mat src_mat
    cdef GpuMat src_gpu
    pyopencv_to(<PyObject*> _src,src_mat)
    src_gpu.upload(src_mat)

    cdef Mat src_mat_2
    cdef GpuMat src_gpu_2
    pyopencv_to(<PyObject*> _M,src_mat_2) 
    src_gpu_2.upload(src_mat_2) 

    cdef Ptr[DescriptorMatcher] matcher= Ptr() 
    matcher = DescriptorMatcher.createBFMatcher(4)
    cdef vector[vector[DMatch]] matches
    matcher.knnMatch(src_gpu,src_gpu_2,2)
    print("no problem so far")

当我试图编译它时,我得到一个错误,说’Ptr [DescriptorMatcher]’没有属性’knnMatch’.

现在据我所知,Ptr是DescriptorMatcher类型的共享指针,所以我从.pxd文件定义Ptr的方式肯定有问题.

我只是不知道如何解决它.如果有人能帮我解决,我将非常感激.

cdef cppclass Ptr[T]:
    Ptr() except + 
    Ptr(Ptr*) except +
    T& operator* () # probably no exceptions

# at the top
from cython.operator cimport dereference

# later
dereference(matcher).knnMatch(src_gpu,2)