310 lines
11 KiB
Python
310 lines
11 KiB
Python
import numpy as np
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import SimpleITK as sitk
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from scipy.ndimage import center_of_mass
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import matplotlib.pyplot as plt
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def azimuth_rotation(image, show_plt=False, save_plt=False, output_path=None):
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img = sitk.ReadImage(image, sitk.sitkUInt8)
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arr_zyx = sitk.GetArrayFromImage(img) # (z, y, x)
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max_proj = np.max(arr_zyx, axis=0) # -> (y, x)
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binary_proj = (max_proj > 0).astype(np.uint8)
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ys, xs = np.where(binary_proj > 0)
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if len(xs) < 10:
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raise ValueError("Not enough foreground points")
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# 2) centroid ←←← 這裡一定會定義 cx, cy
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cy = ys.mean()
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cx = xs.mean()
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centroid = np.array([cy, cx])
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cy = ys.mean()
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cx = xs.mean()
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centroid = np.array([cy, cx])
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y_min = ys.min()
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top_row_mask = (ys == y_min)
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xs_top_row = xs[top_row_mask]
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# 取這一排的中位數或平均值
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x_center = int(np.median(xs_top_row)) # 或用 np.mean()
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top_point = (y_min, x_center)
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# print(f"最上排中心點: {top_point}")
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# 計算從 top_point 到 centroid 的向量
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dy = cy - y_min # y 方向的變化
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dx = cx - x_center # x 方向的變化
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# 計算與 y 軸的夾角
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# 注意：影像座標系中 y 軸向下，所以要特別處理
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angle_rad = np.arctan2(dx, dy) # 弧度
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angle_deg = np.degrees(angle_rad) # 轉成角度
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if show_plt:
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fig = plt.figure(figsize=(12, 12))
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# 視覺化時加上角度資訊
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plt.imshow(binary_proj, cmap='gray')
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plt.scatter(x_center, y_min, c='red', s=60, label='Top')
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plt.scatter(cx, cy, c='yellow', s=60, label='Centroid')
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plt.plot([x_center, cx], [y_min, cy], 'c-', lw=2,
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label=f'Angle with y-axis: {angle_deg:.1f}°')
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plt.legend()
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plt.title("Top point + centroid-directed line")
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plt.axis("off")
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if save_plt:
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if output_path is None:
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output_path = "azimuth_rotation.png"
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fig.savefig(output_path, dpi=200, bbox_inches="tight")
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plt.show()
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plt.close(fig)
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return angle_deg
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def split_spine_anterior_posterior(image_path, center_mode='com'):
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"""
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從 sagittal view 看，沿著 y 軸（前後方向）將脊椎切成前半部和後半部
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Parameters:
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image_path (str): 影像路徑
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center_mode (str): 'com' 使用質心的 y 座標，'image' 使用圖片中心的 y 座標
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Returns:
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anterior, posterior: 前半部和後半部的 binary mask
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"""
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# Sagittal projection: 沿著 x 軸投影 -> (z, y)
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img = sitk.ReadImage(image_path, sitk.sitkUInt8)
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arr_zyx = sitk.GetArrayFromImage(img)
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# Sagittal projection
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max_proj_sagittal = np.max(arr_zyx, axis=2)
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binary_proj = (max_proj_sagittal > 0).astype(np.uint8)
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# 決定切割的 y 座標
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if center_mode == 'com':
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cz, cy = center_of_mass(binary_proj)
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split_y = int(round(cy))
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label = f'Center of Mass (y={split_y})'
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elif center_mode == 'image':
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split_y = binary_proj.shape[1] // 2
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label = f'Image Center (y={split_y})'
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# 檢查是否為數字，且範圍在 0 到 1 之間 (不含邊界)
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elif isinstance(center_mode, (int, float)) and 0 < center_mode < 1:
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ys = np.where(binary_proj > 0)[1]
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if ys.size == 0: # 額外保險：如果投影是空的
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split_y = binary_proj.shape[1] // 2
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else:
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y_min, y_max = ys.min(), ys.max()
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split_y = int(round(y_min + center_mode * (y_max - y_min)))
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label = f'Custom Ratio {center_mode} (y={split_y})'
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else:
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raise ValueError("center_mode 必須是 'com'、'image' 或介於 0 到 1 之間的浮點數 (例如 0.8)")
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# 切割：anterior (y < split_y) 和 posterior (y >= split_y)
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anterior = binary_proj.copy()
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posterior = binary_proj.copy()
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anterior[:, :split_y] = 0 # 保留spine前半部(image後半部)（y >= split_y）
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posterior[:, split_y:] = 0 # 保留spine後半部(image前半部)（y < split_y）
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return anterior, posterior, binary_proj
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def analyze_vertebral_tilt_contour(image_path, edge_type='superior', show_plot=False, debug=False, save_plt=False, output_path=None):
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"""
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通過椎體前緣輪廓分析傾斜（可選上或下終板）
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Parameters:
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edge_type: 'superior' 上終板, 'inferior' 下終板, 'both' 兩者都分析
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"""
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# 切割出 anterior 部分
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anterior, posterior, binary_proj = split_spine_anterior_posterior(image_path, center_mode='com')
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zs, ys = np.where(anterior > 0)
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if len(zs) == 0:
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return None
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from sklearn.linear_model import RANSACRegressor
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results = {}
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# === 根據 edge_type 決定要分析哪些邊 ===
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edges_to_analyze = []
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if edge_type == 'superior' or edge_type == 'both':
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edges_to_analyze.append('superior')
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if edge_type == 'inferior' or edge_type == 'both':
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edges_to_analyze.append('inferior')
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all_edge_points = {}
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all_inliers = {}
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all_outliers = {}
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all_slopes = {}
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all_intercepts = {}
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all_angles = {}
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for edge in edges_to_analyze:
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# 對每個 y，找對應的邊緣點
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edge_points = []
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unique_ys = np.unique(ys)
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for y in unique_ys:
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z_at_y = zs[ys == y]
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if edge == 'superior':
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z_edge = z_at_y.max() # 最上面的點（z 最小）
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else: # inferior
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z_edge = z_at_y.min() # 最下面的點（z 最大）
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edge_points.append([y, z_edge])
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edge_points = np.array(edge_points)
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all_edge_points[edge] = edge_points
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if len(edge_points) < 10:
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continue
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# RANSAC 擬合
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X = edge_points[:, 0].reshape(-1, 1)
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y_data = edge_points[:, 1]
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ransac = RANSACRegressor(
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residual_threshold=5.0,
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random_state=42
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)
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ransac.fit(X, y_data)
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inlier_mask = ransac.inlier_mask_
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outlier_mask = ~inlier_mask
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edge_points_inliers = edge_points[inlier_mask]
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edge_points_outliers = edge_points[outlier_mask]
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all_inliers[edge] = edge_points_inliers
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all_outliers[edge] = edge_points_outliers
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# 獲取擬合結果
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slope = ransac.estimator_.coef_[0]
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intercept = ransac.estimator_.intercept_
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all_slopes[edge] = slope
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all_intercepts[edge] = intercept
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# 計算 R²
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y_pred = ransac.predict(edge_points_inliers[:, 0].reshape(-1, 1))
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ss_res = np.sum((edge_points_inliers[:, 1] - y_pred) ** 2)
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ss_tot = np.sum((edge_points_inliers[:, 1] - np.mean(edge_points_inliers[:, 1])) ** 2)
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r_squared = 1 - (ss_res / ss_tot) if ss_tot > 0 else 0
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# 計算傾斜角度
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tilt_angle = np.degrees(np.arctan(slope))
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all_angles[edge] = tilt_angle
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if debug:
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print(f"\n=== {edge.upper()} ENDPLATE ===")
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print(f"Total points: {len(edge_points)}")
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print(f"Inliers: {len(edge_points_inliers)}")
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print(f"Outliers: {len(edge_points_outliers)}")
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print(f"{edge.capitalize()} 終板傾斜角度: {tilt_angle:.2f}°")
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print(f"斜率: {slope:.4f}, R²: {r_squared:.4f}")
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results[edge] = {
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'tilt_angle_deg': tilt_angle,
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'slope': slope,
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'intercept': intercept,
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'r_squared': r_squared,
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'n_inliers': len(edge_points_inliers),
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'n_outliers': len(edge_points_outliers)
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}
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# Visualization
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if show_plot:
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n_edges = len(edges_to_analyze)
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fig, axes = plt.subplots(n_edges, 2, figsize=(16, 6*n_edges))
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if n_edges == 1:
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axes = axes.reshape(1, -1)
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colors = {'superior': 'red', 'inferior': 'cyan'}
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for idx, edge in enumerate(edges_to_analyze):
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edge_points = all_edge_points[edge]
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edge_points_inliers = all_inliers[edge]
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edge_points_outliers = all_outliers[edge]
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slope = all_slopes[edge]
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intercept = all_intercepts[edge]
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tilt_angle = all_angles[edge]
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color = colors[edge]
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# 左圖：scatter plot
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ax_left = axes[idx, 0]
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if len(edge_points_outliers) > 0:
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ax_left.scatter(edge_points_outliers[:, 0], edge_points_outliers[:, 1],
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c='lightcoral', s=30, alpha=0.6, marker='x',
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label=f'Outliers ({len(edge_points_outliers)})', zorder=3)
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ax_left.scatter(edge_points_inliers[:, 0], edge_points_inliers[:, 1],
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c=color, s=20, alpha=0.7,
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label=f'Inliers ({len(edge_points_inliers)})', zorder=4)
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# 擬合線
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y_line = np.array([edge_points[:, 0].min(), edge_points[:, 0].max()])
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z_line = slope * y_line + intercept
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ax_left.plot(y_line, z_line, 'lime', linewidth=3,
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label=f'Angle: {tilt_angle:.1f}°\nR²: {results[edge]["r_squared"]:.3f}',
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zorder=5)
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ax_left.set_xlabel('y')
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ax_left.set_ylabel('z')
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ax_left.set_title(f'{edge.capitalize()} Endplate Analysis\nTilt: {tilt_angle:.1f}°')
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ax_left.invert_yaxis()
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ax_left.legend()
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ax_left.grid(True, alpha=0.3)
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# 右圖：原始影像
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ax_right = axes[idx, 1]
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ax_right.imshow(anterior, cmap='gray', aspect='equal')
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if len(edge_points_outliers) > 0:
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ax_right.scatter(edge_points_outliers[:, 0], edge_points_outliers[:, 1],
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c='red', s=40, alpha=0.7, marker='x', label='Outliers', zorder=4)
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ax_right.scatter(edge_points_inliers[:, 0], edge_points_inliers[:, 1],
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c=color, s=25, alpha=0.8, label='Inliers', zorder=3)
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ax_right.plot(y_line, z_line, 'lime', linewidth=3, linestyle='--',
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label=f'{edge.capitalize()}: {tilt_angle:.1f}°', zorder=5)
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ax_right.set_title(f'Anterior Half - {edge.capitalize()} Edge')
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ax_right.set_xlabel('y')
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ax_right.set_ylabel('z')
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ax_right.invert_yaxis()
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ax_right.legend()
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plt.tight_layout()
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if save_plt:
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if output_path is None:
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output_path = "analyze_vertebral_tilt_contour.png"
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fig.savefig(output_path, dpi=200, bbox_inches="tight")
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plt.show()
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plt.close(fig)
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return results
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