api_client.py

import os
import time
import numpy as np
import requests
import matplotlib.pyplot as plt

# Disable tensorflow warnings
os.environ['TF_CPP_MIN_LOG_LEVEL'] = '3'

from keras.datasets import mnist
from typing import List


# Set random seed for reproducibility
np.random.seed(50)

# Number of images taken from test dataset to make prediction
N_IMAGES = 9

def get_image_prediction(image: List):
    """Get Model prediction for a given image
    :param
        image: List
            Grayscale Image
    :return: Json
        HTTP Response format:
            {
                "prediction": predicted_label,
                "ml-latency-ms": latency_in_milliseconds
                    (Measures time only for ML operations preprocessing with predict)
        }
    """
    # Making prediction request API
    response = requests.post(url='http://127.0.0.1:5000/predict', json={'image': image})
    # Parse the response JSON
    return response.json()

# Load the dataset from keras.datasets
(x_train, y_train), (x_test, y_test) = mnist.load_data()

# Select N-th (N_IMAGES) random indices from x_test
indices = np.random.choice(len(x_test), N_IMAGES, replace=False)

# Get the images and labels based on the selected indices
images, labels, predictions = x_test[indices], y_test[indices], []

# Iterate over each image, invoke prediction API and save results to predictions array
for i in range(N_IMAGES):
    # Send the POST request to the Flask server
    start_time = time.time()
    model_response = get_image_prediction(images[i].tolist())
    print('Model Response:', model_response)
    print('Total Measured Time (ms):', round((time.time() - start_time) * 1000, 3))
    # Save prediction data into predictions array
    predictions.append(model_response['prediction'])

def plot_images_and_results_plot(images_, labels_, predictions_):
    """Plotting the images with their labels and predictions
    """
    fig, axes = plt.subplots(N_IMAGES, 1, figsize=(6, 10))

    for i in range(N_IMAGES):
        axes[i].imshow(images_[i], cmap='gray')
        axes[i].axis('off')
        axes[i].set_title("Label/Prediction: {}/{}".format(labels_[i], predictions_[i]))

    plt.tight_layout()
    plt.show()

plot_images_and_results_plot(images, labels, predictions)