Privacy Protection Blur using Haar Cascades in OpenCV

blur.py

import cv2
import matplotlib.pyplot as plt

face_cascade = cv2.CascadeClassifier('haarcascades/haarcascade_frontalface_default.xml')
profile_cascade = cv2.CascadeClassifier('haarcascades/haarcascade_profileface.xml')
plate_cascade = cv2.CascadeClassifier('haarcascades/haarcascade_russian_plate_number.xml')


def blur_regions(image, regions):
    for (x, y, w, h) in regions:
        kernel_size = max(1, int(min(w, h) / 3.0))
        kernel_size += kernel_size % 2 - 1
        face_image = image[y:y + h, x:x + w]
        blurred_face = cv2.medianBlur(face_image, kernel_size)
        image[y:y + h, x:x + w] = blurred_face
    return image


def detect_and_blur(image_path):
    image = cv2.imread(image_path)
    original_image = image.copy()
    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)

    faces = face_cascade.detectMultiScale(gray, scaleFactor=1.05, minNeighbors=3)
    image = blur_regions(image, faces)

    profile_faces = profile_cascade.detectMultiScale(gray, scaleFactor=1.05, minNeighbors=3)
    image = blur_regions(image, profile_faces)

    plates = plate_cascade.detectMultiScale(gray, scaleFactor=1.05, minNeighbors=3)
    image = blur_regions(image, plates)

    original_image = cv2.cvtColor(original_image, cv2.COLOR_BGR2RGB)
    image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)

    fig, ax = plt.subplots(1, 2, figsize=(10, 5))
    ax[0].imshow(original_image)
    ax[0].set_title("Original Image")
    ax[1].imshow(image)
    ax[1].set_title("Blurred Image")
    plt.show()