""" Functions to compute distance ratios between specific pairs of facial landmarks """ import numpy as np def calculate_distance_ratio(lmk: np.ndarray, idx1: int, idx2: int, idx3: int, idx4: int, eps: float = 1e-6) -> np.ndarray: """ Calculate the ratio of the distance between two pairs of landmarks. Parameters: lmk (np.ndarray): Landmarks array of shape (B, N, 2). idx1, idx2, idx3, idx4 (int): Indices of the landmarks. eps (float): Small value to avoid division by zero. Returns: np.ndarray: Calculated distance ratio. """ return (np.linalg.norm(lmk[:, idx1] - lmk[:, idx2], axis=1, keepdims=True) / (np.linalg.norm(lmk[:, idx3] - lmk[:, idx4], axis=1, keepdims=True) + eps)) def calc_eye_close_ratio(lmk: np.ndarray, target_eye_ratio: np.ndarray = None) -> np.ndarray: """ Calculate the eye-close ratio for left and right eyes. Parameters: lmk (np.ndarray): Landmarks array of shape (B, N, 2). target_eye_ratio (np.ndarray, optional): Additional target eye ratio array to include. Returns: np.ndarray: Concatenated eye-close ratios. """ lefteye_close_ratio = calculate_distance_ratio(lmk, 6, 18, 0, 12) righteye_close_ratio = calculate_distance_ratio(lmk, 30, 42, 24, 36) if target_eye_ratio is not None: return np.concatenate([lefteye_close_ratio, righteye_close_ratio, target_eye_ratio], axis=1) else: return np.concatenate([lefteye_close_ratio, righteye_close_ratio], axis=1) def calc_lip_close_ratio(lmk: np.ndarray) -> np.ndarray: """ Calculate the lip-close ratio. Parameters: lmk (np.ndarray): Landmarks array of shape (B, N, 2). Returns: np.ndarray: Calculated lip-close ratio. """ return calculate_distance_ratio(lmk, 90, 102, 48, 66)