问将OpenCV IplImage*数据转换为numpy数组

EN

IplImage* do_something(IplImage *img)
{
    // doing nothing
    return img;
}

# Image type (IplImage)
IPL_DEPTH_SIGN = 0x80000000

IPL_DEPTH_1U = 1
IPL_DEPTH_8U = 8
IPL_DEPTH_16U = 16
IPL_DEPTH_32F = 32
IPL_DEPTH_64F = 64

IPL_DEPTH_8S = IPL_DEPTH_SIGN + IPL_DEPTH_8U
IPL_DEPTH_16S = IPL_DEPTH_SIGN + IPL_DEPTH_16U
IPL_DEPTH_32S = IPL_DEPTH_SIGN + 32


# subclassing the ctypes.Structure class to add new features
class _Structure(Structure):
    def __repr__(self):
        """
        Print the fields
        """
        res = []

        for field in self._fields_:
            res.append('%s=%s' % (field[0], repr(getattr(self, field[0]))))

        return self.__class__.__name__ + '(' + ','.join(res) + ')'

class IplTileInfo(_Structure):
    _fields_ = []

class IplROI(_Structure):
    _fields_ = \
    [
        # 0 - no COI (all channels are selected)
        # 1 - 0th channel is selected ...
        ('coi', c_int),
        ('xOffset', c_int),
        ('yOffset', c_int),
        ('width', c_int),
        ('height', c_int),
    ]

# ipl image header
class IplImage(_Structure):
    def __repr__(self):
        """
        Print the fields
        """
        res = []

        for field in self._fields_:
            if field[0] in ['imageData', 'imageDataOrigin']:
                continue

            res.append('%s=%s' % (field[0], repr(getattr(self, field[0]))))

        return self.__class__.__name__ + '(' + ','.join(res) + ')'

IplImage._fields_ = [
    ("nSize", c_int),
    ("ID", c_int),
    ("nChannels", c_int),
    ("alphaChannel", c_int),
    ("depth", c_int),
    ("colorModel", c_char * 4),
    ("channelSeq", c_char * 4),
    ("dataOrder", c_int),
    ("origin", c_int),
    ("align", c_int),
    ("width", c_int),
    ("height", c_int),
    ("roi", POINTER(IplROI)),
    ("maskROI", POINTER(IplImage)),
    ("imageID", c_void_p),
    ("tileInfo", POINTER(IplTileInfo)),
    ("imageSize", c_int),
    ("imageData", c_byte_p),
    ("widthStep", c_int),
    ("BorderMode", c_int * 4),
    ("BorderConst", c_int * 4),
    ("imageDataOrigin", c_char_p)]


class iplimage_t(_Structure):
    _fields_ = \
    [
        ('ob_refcnt', c_ssize_t),
        ('ob_type',  py_object),
        ('ipl_ptr', POINTER(IplImage)),
        ('data', py_object),
        ('offset', c_size_t)
    ]

# gets the dimensions of a numpy ndarray
def get_ndarray_dimensions(img):
    # getting image shape information
    img_shape = img.shape
    img_shape_length = len(img_shape)

    # validating parameters
    if img_shape_length <= 1 or img_shape_length > 3:
        raise ArgumentError('Invalid image information. We support images with 1, 2 or 3 channels only.')

    # getting the amount of channels
    nc = 1 if img_shape_length == 2 else img_shape[2]

    # building the processed image
    h, w = img_shape[0], img_shape[1]

    # returning the height, width and nChannels
    return h, w, nc

def build_ndarray_from_data(iplimage_ptr, img_shape):
    # getting image dimensions
    height, width, n_channels = img_shape

    # getting the IplImage*
    iplimage = iplimage_ptr.contents

    # creating the image header
    cv_img = cv2.cv.CreateImageHeader((width, height), IPL_DEPTH_8U, n_channels)

    # getting the char* from byte data
    str_data = string_at(iplimage.imageData, iplimage.imageSize)

    # setting the image data
    cv2.cv.SetData(cv_img, str_data, iplimage.widthStep)

    # building a CvMat image
    cv_mat = cv_img[:, :]

    # building the ndarray from the CvMat image
    ndarray = np.asarray(cv_mat)

    # returing the built ndarray
    return ndarray

# python wrapper function to the c++ function
def do_something(img):
    # getting the IplImage*
    iplimage_ptr = get_iplimage_ptr(img)

    # calling the c++ function
    ipl_ptr = __c_do_something(iplimage_ptr)

    # getting the image dimensions
    img_shape = get_ndarray_dimensions(img)

    # building the processed image
    proc_img = build_ndarray_from_data(ipl_ptr, img_shape)

    # returning the processed image
    return proc_img

# does something ('pointer' to the c function)
__c_do_something = c_func(
    'do_something', _cdll, POINTER(IplImage),
    ('img', POINTER(IplImage), 1),      # IplImage *img
)

void *return_frame;
extern "C" void* get_rgb_frame(){
        return return_frame;
}
#define FRAME_BUFSIZE (1920 * 1080 * 3 + 1)
return_frame = malloc(FRAME_BUFSIZE);
memset(return_frame, 0x00, FRAME_BUFSIZE + 1);
IplImage* pImg = cvLoadImage("test.jpg",-1);    
memcpy(return_frame, 1920 * 1080 * 3);       
cvReleaseImage(&pImg);

dll.get_rgb_frame.restype = c_void_p
yv12_img = dll.get_rgb_frame()
imagedata = string_at(yv12_img, 1920 * 1080 * 3)
cv_img = cv2.cv.CreateImageHeader((1920, 1080), cv2.cv.IPL_DEPTH_8U, 3)
cv2.cv.SetData(cv_img, imagedata, 3 * 1920)
cv_mat = cv_img[:]
array = np.asarray(cv_mat)
cv2.imshow('jinfeng', array)