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

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

# =========================
# 1. Vẽ Histogram
# =========================
gray = img.convert("L")
gray_array = np.array(gray)

plt.figure("Histogram")
plt.hist(gray_array.ravel(), bins=256, range=[0,256])
plt.title("Histogram")
plt.xlabel("Muc xam")
plt.ylabel("So pixel")
plt.show()

# =========================
# 2. Giảm độ sáng
# MSSV: 2023603389
# 7 số cuối: 3603389
# Tổng = 32
# =========================
img_array = np.array(img)

dark = img_array - 32
dark = np.clip(dark, 0, 255)

dark_img = Image.fromarray(dark.astype(np.uint8))

plt.figure("Giam do sang")
plt.imshow(dark_img)
plt.axis("off")
plt.show()

# =========================
# 3. Phép mở ảnh (OPEN)
# erosion -> dilation
# =========================
binary = gray_array > 128

erosion = ndimage.binary_erosion(binary)
opening = ndimage.binary_dilation(erosion)

plt.figure("OPEN")
plt.imshow(opening, cmap="gray")
plt.axis("off")
plt.show()

# =========================
# 4. Phát hiện biên Canny
# =========================
from skimage import feature

edges = feature.canny(gray_array, sigma=1)

plt.figure("Canny")
plt.imshow(edges, cmap="gray")
plt.axis("off")
plt.show()