重构-抽纯函数

app/tests/eotf.py

@@ -0,0 +1,40 @@
+"""EOTF（PQ / ST.2084）相关纯算法。"""
+
+import numpy as np
+
+
+def calculate_pq_curve(gray_levels):
+    """计算 PQ (ST.2084) EOTF 理想曲线。
+
+    Args:
+        gray_levels: 灰阶百分比数组 (0-100)
+
+    Returns:
+        numpy.ndarray: 归一化亮度数组 (0-1)
+    """
+    # PQ 曲线参数（ITU-R BT.2100 标准）
+    m1 = 0.1593017578125   # = 2610 / 16384
+    m2 = 78.84375          # = 78.84375
+    c1 = 0.8359375         # = 3424 / 4096
+    c2 = 18.8515625        # = 2413 / 128
+    c3 = 18.6875           # = 2392 / 128
+
+    L_bar = []
+    for gray in gray_levels:
+        V = gray / 100.0
+
+        if V <= 0:
+            L_bar.append(0)
+        else:
+            V_pow = np.power(V, 1 / m2)
+            numerator = max(V_pow - c1, 0)
+            denominator = c2 - c3 * V_pow
+
+            if denominator > 0:
+                L = np.power(numerator / denominator, 1 / m1)
+            else:
+                L = 0
+
+            L_bar.append(L)
+
+    return np.array(L_bar)