quantization.py

import cv2
import numpy as np
import matplotlib.pyplot as plt

# Read image
img = cv2.imread('image.jpg', cv2.IMREAD_GRAYSCALE)

# Check if image is loaded
if img is None:
    print("Error: Image not found. Make sure 'image.jpg' is in the same folder.")
    exit()

# ----- Sampling -----
# Reduce image size (sampling)
sampled_img = cv2.resize(img, (128, 128), interpolation=cv2.INTER_NEAREST)

# ----- Quantization -----
levels = 16  # You can try: 2, 4, 8, 16, 32
quant_step = 256 // levels
quantized_img = (img // quant_step) * quant_step

# Display output
plt.figure(figsize=(12, 4))

plt.subplot(1, 3, 1)
plt.title("Original Image")
plt.imshow(img, cmap='gray')
plt.axis('off')

plt.subplot(1, 3, 2)
plt.title("Sampled Image (128x128)")
plt.imshow(sampled_img, cmap='gray')
plt.axis('off')

plt.subplot(1, 3, 3)
plt.title(f"Quantized Image ({levels} levels)")
plt.imshow(quantized_img, cmap='gray')
plt.axis('off')

plt.show()