Christos Choutouridis 36dd4b3c5e HW03: demo3a,b,c added
2025-07-05 20:49:06 +03:00

60 lines
1.7 KiB
Python

#
# Demo 3a: Non-recursive normalized cuts
#
# author: Christos Choutouridis <cchoutou@ece.auth.gr>
# date: 06/07/2025
#
try:
# Testing requirements
from scipy.io import loadmat
import matplotlib.pyplot as plt
import numpy as np
# Project imports
from normalized_cuts import n_cuts
from spectral_clustering import spectral_clustering
from image_to_graph import image_to_graph
except ImportError as e:
print("Missing package:", e)
print("Run: pip install -r requirements.txt")
exit(1)
def plot_segmentation(image, labels, k, title, fname):
M, N, _ = image.shape
segmented = labels.reshape(M, N)
plt.imshow(segmented, cmap='tab10', vmin=0, vmax=k-1)
plt.title(title)
plt.axis('off')
plt.tight_layout()
plt.savefig(fname)
print(f"Saved: {fname}")
plt.close()
def run_demo3a():
data = loadmat("dip_hw_3.mat")
for name in ["d2a", "d2b"]:
img = data[name]
print(f"\n=== Image {name} ===")
affinity = image_to_graph(img)
for k in [2, 3, 4]:
print(f" k = {k}")
labels_nc = n_cuts(affinity, k=k)
labels_sc = spectral_clustering(affinity, k=k, normalized=False)
labels_sc_nrm = spectral_clustering(affinity, k=k, normalized=True)
plot_segmentation(img, labels_nc, k, f"{name} - n_cuts (k={k})", f"plots/demo3a_{name}_ncuts_k{k}.png")
plot_segmentation(img, labels_sc, k, f"{name} - spectral (k={k})", f"plots/demo3a_{name}_spectral_k{k}.png")
plot_segmentation(img, labels_sc_nrm, k, f"{name} - spectral-Lnorm (k={k})", f"plots/demo3a_{name}_spectral_k{k}_norm.png")
if __name__ == '__main__':
run_demo3a()