python ガウシアンフィルタ

Posted 2021-05-09

#! /usr/bin/env python3
# -*- coding: utf-8 -*-

import cv2
import numpy as np

src = cv2.imread("./Lenna.bmp", -1)
dst = np.zeros_like(src)

def pickup_pixel(img, x, y):
  row_len, cal_len = src.shape
  if x < 0:
    x = 0
  if y < 0:
    y = 0
  if x > row_len-1:
    x = row_len-1
  if y > cal_len-1:
    y = cal_len-1
  return img[x, y]

row_len, cal_len = src.shape

g_filter = [
  [1.0/256, 4.0/256, 6.0/256, 4.0/256, 1.0/246],
  [4.0/256, 16.0/256, 24.0/256, 16.0/256, 4.0/246],
  [6.0/256, 24.0/256, 36.0/256, 24.0/256, 6.0/246],
  [4.0/256, 16.0/256, 24.0/256, 16.0/256, 4.0/246],
  [1.0/256, 4.0/256, 6.0/256, 4.0/256, 1.0/246],
]

print(row_len, cal_len)
print(g_filter)

for x in range(row_len):
  for y in range(cal_len):

    dst_pixel = 0.0

    for n in range(5):
      for m in range(5):
        pixel = pickup_pixel(src, x+n-2, y+m-2)
        dst_pixel = dst_pixel + pixel*g_filter[n][m]

    dst[x, y] = int(dst_pixel)

cv2.imshow("result", dst)
cv2.waitKey(0)
cv2.destroyAllWindows()