pip install pillow matplotlib numpy scipy

from PIL import Image
import matplotlib.pyplot as plt
import numpy as np
from scipy import ndimage

# =====================================
# Đọc ảnh
# =====================================
img = Image.open("test.jpg")

# Chuyển sang ảnh xám
gray = img.convert("L")

gray_array = np.array(gray)
gray_float = gray_array.astype(np.float32)

# =====================================
# 1. Histogram
# =====================================
plt.figure(figsize=(6,4))
plt.hist(gray_array.ravel(), bins=256, range=(0,256))
plt.title("Histogram")
plt.xlabel("Muc xam")
plt.ylabel("So pixel")
plt.show()

# =====================================
# 2.1. Tăng độ tương phản
# =====================================
contrast = np.clip(
    1.5 * (gray_float - 128) + 128,
    0,
    255
).astype(np.uint8)

# =====================================
# 2.2. Giảm độ tương phản
# =====================================
low_contrast = np.clip(
    0.5 * (gray_float - 128) + 128,
    0,
    255
).astype(np.uint8)

# =====================================
# 3.1. Mean Filter
# =====================================
mean_filter = ndimage.uniform_filter(
    gray_array,
    size=3
)

# =====================================
# 3.2. Median Filter
# =====================================
median_filter = ndimage.median_filter(
    gray_array,
    size=3
)

# =====================================
# 4.1. Prewitt
# =====================================
prewitt_x = ndimage.prewitt(
    gray_float,
    axis=1
)

prewitt_y = ndimage.prewitt(
    gray_float,
    axis=0
)

prewitt = np.hypot(
    prewitt_x,
    prewitt_y
)

if prewitt.max() > 0:
    prewitt = (
        prewitt / prewitt.max()
    ) * 255

prewitt = prewitt.astype(np.uint8)

# =====================================
# 4.2. Laplacian
# =====================================
laplace = ndimage.laplace(
    gray_float
)

laplace = np.abs(laplace)

if laplace.max() > 0:
    laplace = (
        laplace / laplace.max()
    ) * 255

laplace = laplace.astype(np.uint8)

# =====================================
# Hiển thị kết quả
# =====================================
plt.figure(figsize=(15,10))

plt.subplot(2,3,1)
plt.imshow(contrast, cmap="gray")
plt.title("Tang tuong phan")
plt.axis("off")

plt.subplot(2,3,2)
plt.imshow(low_contrast, cmap="gray")
plt.title("Giam tuong phan")
plt.axis("off")

plt.subplot(2,3,3)
plt.imshow(mean_filter, cmap="gray")
plt.title("Mean Filter")
plt.axis("off")

plt.subplot(2,3,4)
plt.imshow(median_filter, cmap="gray")
plt.title("Median Filter")
plt.axis("off")

plt.subplot(2,3,5)
plt.imshow(prewitt, cmap="gray")
plt.title("Prewitt")
plt.axis("off")

plt.subplot(2,3,6)
plt.imshow(laplace, cmap="gray")
plt.title("Laplacian")
plt.axis("off")

plt.tight_layout()
plt.show()