python - How can I avoid the overflow?

Question

I need to convert an image to HSV. I used the library OpenCV but when I run my algorithm I have the following warning:

RuntimeWarning: overflow encountered in ubyte_scalars

I want to calculate distance between two HSV piexels. I implemented the function:

def distance(pixel1, pixel2):
    h1, s1, v1 = pixel1[0], pixel1[1], pixel1[2]
    h2, s2, v2 = pixel2[0], pixel2[1], pixel2][2]
    dh = abs(h1 - h2) / 179
    ds = abs(s1 - s2) / 255
    dv = abs(v1 - v2) / 255
    distance = math.sqrt(dh ** 2 + ds ** 2 + dv ** 2) / math.sqrt(3)
return distance

When I execute the following code the results are not correct because of the overflow. In some cases the distance is grater than 1.0 and that shouldn't happen.

  import cv2
  import math
  import numpy as np
  #threshold value in range (0,1]
  threshold = 0.7689
  image1 = cv2.imread("image1.jpg")
  image2 = cv2.fastNlMeansDenoisingColored(image1,None,10,10,7,21)
  image3 = cv2.cvtColor(image2, cv2.COLOR_BGR2HSV)
  w, h, c = image3.shape
  binary_image = np.zeros((w, h), dtype= int)
  # extract one pixel from image
  pixel1 = image3[w//2][h//2]
  for i in range(w):
      for j in range(h):
         distance = distance(pixel1, image3[i][j])
         if distance > threshold:
             binary_image[i][j] = 1
         else:
             binary_image[i][j] = 0

I tried to do the following change, after I read the image

image4 = np.array(image3, dtype = 'float64')

If I change the type of the array the distance becomes extremely small (< 0.01) and the threshold value can't be applied.

How can I change my code in order to avoid overflow?

Answer 1

等待大神答复