convert the caltech101 mat file to images
    Examples
    --------
    python convert_data.py --dataset /home/ubuntu/datasets/caltech101/data/caltech101_silhouettes_28.mat --save_path /home/ubuntu/datasets/caltech101/data/ --invert --height 32 --width 32

def convert_mat_to_images(args):
    '''convert the caltech101 mat file to images
    Examples
    --------
    python convert_data.py --dataset /home/ubuntu/datasets/caltech101/data/caltech101_silhouettes_28.mat --save_path /home/ubuntu/datasets/caltech101/data/ --invert --height 32 --width 32
    '''
    dataset = scipy.io.loadmat("{}/{}".format(args.save_path, args.dataset))

    # image pixel data
    X = dataset['X']

    # image class labels (not used in this project)
    Y = dataset['Y']

    total_image = X.shape[0]

    h=args.height
    w=args.width

    for i in range(total_image):
        img = X[i]
        img = np.reshape(img, (28, 28))
        if args.invert:
            img = (1-img)*255
        else:
            img = img*255
        img = Image.fromarray(img, 'L')
        img = img.rotate(-90)
        img = img.resize([h, w], Image.BILINEAR)
        img.save(args.save_path + '/img' + str(i) + '.png')