Python, face_recognition convert string to array - arrays

Question

I want to convert a variable to a string and then to an array that I can use to compare, but i dont know how to do that.
my code:
import face_recognition
import numpy as np
a = face_recognition.load_image_file('C:\\Users\zivsi\OneDrive\תמונות\סרט צילום\WIN_20191115_10_32_24_Pro.jpg') # my picture 1
b = face_recognition.load_image_file('C:\\Users\zivsi\OneDrive\תמונות\סרט צילום\WIN_20191115_09_48_56_Pro.jpg') # my picture 2
c = face_recognition.load_image_file(
'C:\\Users\zivsi\OneDrive\תמונות\סרט צילום\WIN_20191115_09_48_52_Pro.jpg') # my picture 3
d = face_recognition.load_image_file('C:\\Users\zivsi\OneDrive\תמונות\סרט צילום\ziv sion.jpg') # my picture 4
e = face_recognition.load_image_file(
'C:\\Users\zivsi\OneDrive\תמונות\סרט צילום\WIN_20191120_17_46_40_Pro.jpg') # my picture 5
f = face_recognition.load_image_file(
'C:\\Users\zivsi\OneDrive\תמונות\סרט צילום\WIN_20191117_16_19_11_Pro.jpg') # my picture 6
a = face_recognition.face_encodings(a)[0]
b = face_recognition.face_encodings(b)[0]
c = face_recognition.face_encodings(c)[0]
d = face_recognition.face_encodings(d)[0]
e = face_recognition.face_encodings(e)[0]
f = face_recognition.face_encodings(f)[0]
Here I tried to convert the variable to a string
str_variable = str(a)
array_variable = np.array(str_variable)
my_face = a, b, c, d, e, f, array_variable
while True:
new = input('path: ')
print('Recognizing...')
unknown = face_recognition.load_image_file(new)
unknown_encodings = face_recognition.face_encodings(unknown)[0]
The program cannot use the variable:
results = face_recognition.compare_faces(array_variable, unknown_encodings, tolerance=0.4)
print(results)
recognize_times = int(results.count(True))
if (3 <= recognize_times):
print('hello boss!')
my_face = *my_face, unknown_encodings
please help me
The error shown:
Traceback (most recent call last):
File "C:/Users/zivsi/PycharmProjects/AI/pytt.py", line 37, in <module>
results = face_recognition.compare_faces(my_face, unknown_encodings, tolerance=0.4)
File "C:\Users\zivsi\AppData\Local\Programs\Python\Python36\lib\site-
packages\face_recognition\api.py", line 222, in compare_faces
return list(face_distance(known_face_encodings, face_encoding_to_check) <= tolerance)
File "C:\Users\zivsi\AppData\Local\Programs\Python\Python36\lib\site-packages\face_recognition\api.py", line 72, in face_distance
return np.linalg.norm(face_encodings - face_to_compare, axis=1)
ValueError: operands could not be broadcast together with shapes (7,) (128,)

Answer 1

First of all, the array_variable should actually be a list of the known encodings and not a numpy array.
Also you do not need str.
Now, in your case, if the input images i.e., a,b,c,d,f,e do NOT have the same dimensions, the error will persist. You can not compare images that have different sizes using this function. The reason is that the comparison is based on the distance and distance is defined on vectors of the same length.
Here is a working simple example using the photos from https://github.com/ageitgey/face_recognition/tree/master/examples:
import face_recognition
import numpy as np
from PIL import Image, ImageDraw
from IPython.display import display
# Load a sample picture and learn how to recognize it.
obama_image = face_recognition.load_image_file("obama.jpg")
obama_face_encoding = face_recognition.face_encodings(obama_image)[0]
# Load a second sample picture and learn how to recognize it.
biden_image = face_recognition.load_image_file("biden.jpg")
biden_face_encoding = face_recognition.face_encodings(biden_image)[0]
array_variable = [obama_face_encoding,biden_face_encoding] # list of known encodings
# compare the list with the biden_face_encoding
results = face_recognition.compare_faces(array_variable, biden_face_encoding, tolerance=0.4)
print(results)
[False, True] # True means match, False mismatch
# False: coming from obama_face_encoding VS biden_face_encoding
# True: coming from biden_face_encoding VS biden_face_encoding
To run it go here: https://beta.deepnote.com/project/09705740-31c0-4d9a-8890-269ff1c3dfaf#
Documentation: https://face-recognition.readthedocs.io/en/latest/face_recognition.html
EDIT
To save the known encodings you can use numpy.save
np.save('encodings',biden_face_encoding) # save
load_again = np.load('encodings.npy') # load again