find_image_v2.py

import sys
import numpy as np
from PIL import Image

def verify(haystack_start_y, haystack_start_x, arr_haystack, arr_needle):
  y = haystack_start_y
  x = haystack_start_x
  searched = 0
  identical = 0
  for b in range(0, len(arr_needle)):
    for a in range(0, len(arr_needle[0])):
      searched = searched + 1
      if list(arr_needle[b][a]) == list(arr_haystack[y+b][x+a]):
        identical = identical + 1
  return identical/searched
#-------------------------------------------------------

def search_image(png_haystack, png_needle):
  arr_haystack = np.array(png_haystack)
  arr_needle = np.array(png_needle)
  if len(arr_haystack)<len(arr_needle) or len(arr_haystack[0])<len(arr_needle[0]):
    return [[-1,-1]]
  height = len(arr_needle) #row
  width = len(arr_needle[0]) #column
  pixel_top_left = arr_needle[0][0]
  pixel_bottom_left = arr_needle[height-1][0]
  pixel_top_right = arr_needle[0][width-1]
  pixel_bottom_right = arr_needle[height-1][width-1]

  results1 = []
  for y in range(0, len(arr_haystack)):
    for x in range(0, len(arr_haystack[0])):
      if list(arr_haystack[y][x]) == list(pixel_top_left):
        results1.append([y,x])

  results2 = []
  for n in range(0, len(results1)):
    y = results1[n][0]
    x = results1[n][1]
    if list(arr_haystack[y+height-1][x]) == list(pixel_bottom_left):
      results2.append([y,x])

  results3 = []
  for n in range(0, len(results2)):
    y = results2[n][0]
    x = results2[n][1]
    if list(arr_haystack[y][x+width-1]) == list(pixel_top_right):
      results3.append([y,x])
      
  results4 = []
  for n in range(0, len(results3)):
    y = results3[n][0]
    x = results3[n][1]
    if list(arr_haystack[y+height-1][x+width-1]) == list(pixel_bottom_right):
      results4.append([y,x])

  results5 = []
  for n in range(0, len(results4)):
    y = results4[n][0]
    x = results4[n][1]
    if verify(y, x, arr_haystack, arr_needle) == 1.0:
      results5.append([x,y])

  if len(results5) == 0:
    return [[-1,-1]]
  else:
    return results5
#-------------------------------------------------------

png_haystack = Image.open(sys.argv[1])
png_needle = Image.open(sys.argv[2])
print(search_image(png_haystack, png_needle))