I’m working on a project to calculate the level of a chest deformity.
For that I need to find the inner contour of the chest from the tomography, however I don’t know how to select the inner contour.

First I converted the image to binary and applied threshold.

import cv2
import numpy as np
from PIL import Image

import matplotlib.pyplot as plt

def process_and_plot(image_path):
    def process(image_path):
        image = cv2.imread(image_path)
        gray_image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
        blurred_image = cv2.GaussianBlur(gray_image, (5, 5), 0)
        _, binary_image = cv2.threshold(blurred_image, 127, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)
        return binary_image

    fig, axes = plt.subplots(1, 2, figsize=(10, 5))

    img = Image.open(image_path)
    axes[0].imshow(img, cmap='gray')
    axes[0].set_title('Original Image')

    processed_image = process(image_path)
    axes[1].imshow(processed_image, cmap='gray')  
    axes[1].set_title('Processed Image')

    plt.show()

process_and_plot('test.jpeg')

What I’m expecting is to get the red contour.