Create your own dataset for machine learning, same format as CIFAR-10 dataset, via PIL and numpy

Refers:
http://www.cs.toronto.edu/~kriz/cifar.html
https://www.tensorflow.org/tutorials/deep_cnn


The CIFAR-10 dataset consists of 60000 32x32 colour images in 10 classes.

ClixSense Click on the cat job use the image that its size is 128 x 96 px, and
the image is cat or dog, no other type.
I want to use CNN to do machine learning for this job. 
I collected some images now.

The key python codes to append one image with label to the dataset is as below:

from PIL import Image
import numpy as np   im = Image.open(filename)
  im = (np.array(im))

  r = im[:,:,0].flatten()
  g = im[:,:,1].flatten()
  b = im[:,:,2].flatten()

  if iscat:
    label = [0]
  else:
    label = [1]

  out  = np.array(list(label) + list(r) + list(g) + list(b), np.uint8)
  out.tofile(dataset)