why I got parameter must be 2D array error when I used imread with grayscale image?-CodePudding

I got an error in feature.local_binary_pattern

I used imread(img_path, cv2.COLOR_BGR2GRAY) but it didn't fix it.

The images that I read is grayScale

THE FULL Error message:

Traceback (most recent call last):
  File "/Users/myname/PycharmProjects/pythonProject1/main.py", line 76, in <module>
    lbp.append(feature.local_binary_pattern(img, 8, 3, method="default"))
  File "/Users/myname/PycharmProjects/pythonProject1/venv/lib/python3.8/site-packages/skimage/feature/texture.py", line 333, in local_binary_pattern
    check_nD(image, 2)
  File "/Users/myname/PycharmProjects/pythonProject1/venv/lib/python3.8/site-packages/skimage/_shared/utils.py", line 655, in check_nD
    raise ValueError(

ValueError: The parameter `image` must be a 2-dimensional array

import cv2
import numpy as np
import os
import matplotlib.pyplot as plt
import random
from skimage import feature #-> python -m pip install -U scikit-image
from PIL import  ImageOps

#load and labeling the data
#__________________________________________________________________________

DIRECTORY ="/Users/myname/Desktop/LSB"
FILES = ['cover', 'stego']
data = []

for file in FILES:
    path = os.path.join(DIRECTORY, file)
    for img in os.listdir(path):
        img_path = os.path.join(path, img)
        #print(img_path)
        label = FILES.index(file)
        img = cv2.imread(img_path, cv2.COLOR_BGR2GRAY)
        data.append([img, label])

random.shuffle(data)

X=[]
y=[]

for features, label in data:
    X.append(features)
    y.append(label)

X = np.array(X)
y = np.array(y)

 #print(" x[3].shape->" , np.shape(X[3])) ->-> gives me  : x[3].shape-> ()

#LBP feature extraction
#__________________________________________________________________________

lbp =[]

for img in X :  
    print( "**** image shape -> ", np.shape(img) #print only first two images 

    lbp.append(feature.local_binary_pattern(img, 8, 3, method="default"))

CodePudding user response：

When I run your code with image RGB then I get (512,512,3) - even if it use cv2.COLOR_BGR2GRAY in imread() - and this can make your problem.

You use wrong value in imread()- it has to be cv2.IMREAD_GRAYSCALE

img = cv2.imread(img_path, cv2.IMREAD_GRAYSCALE)

And value cv2.COLOR_BGR2GRAY is for function

img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

EDIT:

It seems you have another problem.

When cv2 can't read file then it doesn't raise error but it returns None - and later it makes problem. You will have to use if/else to skip this image

if img is not None:  # can't be `if not img:`
   data.append([img, label])
else:
   print("can't read:", img_path)

You may have to also use some external program to convert this image to other format.

CodePudding user response：

Problem is fixed

the problem was because None values in the array for some reason it read from empty file so i used if which will not read the empty file

for img in os.listdir(path):
        if img!='.DS_Store':
            img_path = os.path.join(path, img)
            print("img path ",  " ", img)
            label = FILES.index(file)
            img = cv2.imread(img_path, cv2.IMREAD_GRAYSCALE)
            data.append([img, label])

enter image description here