EP08_10 — 🔴 Low Contrast and Object Separation Topics ( Watershed / Distance)

8.14.10 EP08_10 🔴 Low Contrast and Object Separation Topics (Watershed / Distance)

In this exercise, some geometric objects are slightly touching (overlapping at the edges). Simply extracting contours would treat two objects as one.

8.14.10.1 📋 Implementation Guidelines

Input: an \(H \times W\) grayscale matrix with objects of intensity \(110\dots140\) on a background of \(0\), with noise and a pair of tangent objects.
Preprocessing and Separation:

Apply thresholding.
Apply the Distance Transform (mm.dist).
Obtain distance peaks to serve as markers in the Watershed Transform (mm.watershed), physically separating the touching objects in the mask. Hint: use mm.regmax() to obtain the local maxima and then label them with mm.label0.
After the watershed, apply thresholding again with mm.threshold(water,0)//255.

Connected Component Analysis: measure each isolated region after the watershed.
Output: print the components sorted by (bbox[0], bbox[1]) with their individual area, centroid, and solidity metrics.
- For sorting, use medidas.sort(key=lambda m: (m['bbox'][1], m['bbox'][0])), with medidas = mm.measure(img, precision=0.02).

8.14.10.2 📌 Examples

Input	Output
16 16 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 … (binary image containing two squares)	id area perimeter cx cy x y w h solidity 1 16.0 16.0 5.0 5.0 3 3 5 5 1.000 2 16.0 16.0 11.0 5.0 9 3 5 5 1.000

🧮 Simulator EP08_10: Separation of Tangent Disks (L2 Transform & Watershed) mm.dist L2 → mm.watershed → Measurement

MORPHOLOGICAL PROCESSING STEP

PIXEL MATRIX VISUALIZATION

DISK MEASUREMENTS TABLE AFTER WATERSHED CUT

id	area	perimeter	cx	cy	x	y	w	h	circularity	solidity	vertices

Figure 8.24: EP08_10 Simulator: Separation of Tangent Disks via L2 Distance Transform and Watershed

%%writefile EP08_10.py
# Python code

Overwriting EP08_10.py

TestSuite("EP08_10.py").run()

✔️ EP08_10.cases already exists in casos/
📋 3 case(s) loaded from casos/EP08_10.cases

🔍 Testing Python: EP08_10.py
⚠️ EP08_10.py: Empty file (fewer than 3 lines). Tests skipped.