How to create a similar image dataset of mnist with shape (12500, 50,50)

Question

How to create a similar image dataset of mnist with shape (12500, 50,50)

I have a folder with 12500 images. I want to generate a datset with these images to work with sorting images in keras. I want to generate a dataset similar to mnist so that with shape (12500, 50,50). I'm wrapped up in creating the code to generate the dataset. I'm trying to create a numpy array but it's not getting the format I want. I believe I should use the opencv resize function to leave all images with height and width with 50x50 shape. Grateful for the attention

import cv2
import glob
import numpy as np

X_data = []
files = glob.glob ("C:/Teste_datasets/PetImages/Cat/*.jpg")

for myFile in files:
    print(myFile)
    image = cv2.imread (myFile, cv2.IMREAD_GRAYSCALE)
    X_data.append (image)

X_data = np.array(X_data)

X_data = X_data.astype('float32') / 255

IMG_SIZE = 50

X_data = cv2.resize(X_data, (IMG_SIZE, IMG_SIZE))

X_data = X_data.reshape((X_data.shape[0], 50, 50,1))

Answer 1

You should resize images, instead of the whole dataset:

import cv2
import glob
import numpy as np

X_data = []
files = glob.glob ("C:/Teste_datasets/PetImages/Cat/*.jpg")
IMG_SIZE = 50

for myFile in files:
    print(myFile)
    image = cv2.imread (myFile, cv2.IMREAD_GRAYSCALE)
    image = cv2.resize(image, (IMG_SIZE, IMG_SIZE))
    X_data.append (image)

X_data = np.array(X_data)
X_data = X_data.astype('float32') / 255

print(X_data.shape)

[daniel@daniel-pc Keras]$ python3 testeKeras.py
<...>/2.png
<...>/1.png
(2, 50, 50)

Also, there's no reason to reshape, because since you load the image with cv2.IMREAD_GRAYSCALE you already have a single value representing the color.