openCV 3.0 python LineIterator

Question

Ich möchte die LineIterator in openCV 3.0 mit Python verwenden, ist es immer noch mit OpenCV 3.0 für Python gebaut? Es scheint, dass die Antworten im Internet alle auf cv.InitLineIterator zeigen, der Teil des cv-Moduls ist. Ich habe versucht, dieses Modul zu importieren, aber es scheint, als wäre es nicht im aktuellen Build enthalten. Wurde es umbenannt oder strikt entfernt?

Answer 1

Ich habe mein eigenes Problem gelöst. Der Zeileniterator scheint in der cv2-Bibliothek nicht verfügbar zu sein. Daher habe ich meinen eigenen Zeilen-Iterator erstellt. Es werden keine Loops verwendet, daher sollte es ziemlich schnell sein. Hier ist der Code, wenn jemand es braucht:

def createLineIterator(P1, P2, img): 
    """ 
    Produces and array that consists of the coordinates and intensities of each pixel in a line between two points 

    Parameters: 
     -P1: a numpy array that consists of the coordinate of the first point (x,y) 
     -P2: a numpy array that consists of the coordinate of the second point (x,y) 
     -img: the image being processed 

    Returns: 
     -it: a numpy array that consists of the coordinates and intensities of each pixel in the radii (shape: [numPixels, 3], row = [x,y,intensity])  
    """ 
    #define local variables for readability 
    imageH = img.shape[0] 
    imageW = img.shape[1] 
    P1X = P1[0] 
    P1Y = P1[1] 
    P2X = P2[0] 
    P2Y = P2[1] 

    #difference and absolute difference between points 
    #used to calculate slope and relative location between points 
    dX = P2X - P1X 
    dY = P2Y - P1Y 
    dXa = np.abs(dX) 
    dYa = np.abs(dY) 

    #predefine numpy array for output based on distance between points 
    itbuffer = np.empty(shape=(np.maximum(dYa,dXa),3),dtype=np.float32) 
    itbuffer.fill(np.nan) 

    #Obtain coordinates along the line using a form of Bresenham's algorithm 
    negY = P1Y > P2Y 
    negX = P1X > P2X 
    if P1X == P2X: #vertical line segment 
     itbuffer[:,0] = P1X 
     if negY: 
      itbuffer[:,1] = np.arange(P1Y - 1,P1Y - dYa - 1,-1) 
     else: 
      itbuffer[:,1] = np.arange(P1Y+1,P1Y+dYa+1)    
    elif P1Y == P2Y: #horizontal line segment 
     itbuffer[:,1] = P1Y 
     if negX: 
      itbuffer[:,0] = np.arange(P1X-1,P1X-dXa-1,-1) 
     else: 
      itbuffer[:,0] = np.arange(P1X+1,P1X+dXa+1) 
    else: #diagonal line segment 
     steepSlope = dYa > dXa 
     if steepSlope: 
      slope = dX.astype(np.float32)/dY.astype(np.float32) 
      if negY: 
       itbuffer[:,1] = np.arange(P1Y-1,P1Y-dYa-1,-1) 
      else: 
       itbuffer[:,1] = np.arange(P1Y+1,P1Y+dYa+1) 
      itbuffer[:,0] = (slope*(itbuffer[:,1]-P1Y)).astype(np.int) + P1X 
     else: 
      slope = dY.astype(np.float32)/dX.astype(np.float32) 
      if negX: 
       itbuffer[:,0] = np.arange(P1X-1,P1X-dXa-1,-1) 
      else: 
       itbuffer[:,0] = np.arange(P1X+1,P1X+dXa+1) 
      itbuffer[:,1] = (slope*(itbuffer[:,0]-P1X)).astype(np.int) + P1Y 

    #Remove points outside of image 
    colX = itbuffer[:,0] 
    colY = itbuffer[:,1] 
    itbuffer = itbuffer[(colX >= 0) & (colY >=0) & (colX<imageW) & (colY<imageH)] 

    #Get intensities from img ndarray 
    itbuffer[:,2] = img[itbuffer[:,1].astype(np.uint),itbuffer[:,0].astype(np.uint)] 

    return itbuffer