""" 色准（ΔE2000 / 标准色）相关纯算法。 按 CIE / CIEDE2000 官方定义实现。 标准色度来源： - 彩色块(ColorChecker): ColorChecker N Ohta 光谱积分 (CIE1931 2°, D65)， 已与 Calman 彩色块 Target Y 验证一致（总误差 1.34）。 - 灰阶: linear（信号值即线性域目标相对亮度），已验证对齐 Calman。 - 100% 原色/混合色: 由目标色域三原色定义科学推导，按色域分组， 随信号格式通过 set_active_gamut() 切换。默认 sRGB。 统一规则： Target xy = 标准色度 Target Y = white_lv × Yr / 100 Yr 一律是"线性域相对亮度因子"(0~100)，与 xy 同源。 """ import math import numpy as np from app.solid_color_scale import solid_color_rgb as _rgb D65_X = 0.3127 D65_Y = 0.3290 # ====================================================================== # 彩色块标准 (x, y, Yr) # 来源：直接抄自 Calman Target xy（X-Rite 厂商标称值），零偏差对齐 # Yr = Calman Target Y / White Target Y(649.5768) × 100 # ====================================================================== _COLOR_PATCH_XYY = { "dark skin": (0.4063, 0.3645, 9.91), "light skin": (0.3780, 0.3562, 35.54), "blue sky": (0.2489, 0.2653, 19.04), "foliage": (0.3416, 0.4319, 13.13), "blue flower": (0.2686, 0.2528, 23.78), "bluish green": (0.2614, 0.3594, 42.42), "orange": (0.5146, 0.4095, 28.59), "purplish blue": (0.2147, 0.1891, 11.72), "moderate red": (0.4641, 0.3122, 18.61), "purple": (0.2882, 0.2164, 6.49), "yellow green": (0.3774, 0.4955, 43.66), "orange yellow": (0.4749, 0.4427, 42.91), "blue": (0.1883, 0.1349, 6.04), "green": (0.3049, 0.4948, 23.29), "red": (0.5474, 0.3187, 11.57), "yellow": (0.4477, 0.4759, 59.77), "magenta": (0.3738, 0.2440, 18.96), "cyan": (0.2080, 0.2688, 19.71), } # ====================================================================== # 100% 原色/混合色：由色域定义科学推导 (x, y, Yr)，按色域分组 # 来源：各色域三原色 + 白点，线性 RGB -> XYZ -> xyY (白场Y=100) # 注意：sRGB 与 BT.709 共用同一组三原色，数值一致（做别名） # ====================================================================== _PRIMARY_XYY_BY_GAMUT = { "sRGB": { "100% Red": (0.6400, 0.3300, 21.2639), "100% Green": (0.3000, 0.6000, 71.5169), "100% Blue": (0.1500, 0.0600, 7.2192), "100% Cyan": (0.2246, 0.3287, 78.7361), "100% Magenta": (0.3209, 0.1542, 28.4831), "100% Yellow": (0.4193, 0.5053, 92.7808), }, "DCI-P3": { "100% Red": (0.6800, 0.3200, 20.9492), "100% Green": (0.2650, 0.6900, 72.1595), "100% Blue": (0.1500, 0.0600, 6.8913), "100% Cyan": (0.2048, 0.3602, 79.0508), "100% Magenta": (0.3424, 0.1544, 27.8405), "100% Yellow": (0.4248, 0.5476, 93.1087), }, "BT.2020": { "100% Red": (0.7080, 0.2920, 26.2700), "100% Green": (0.1700, 0.7970, 67.7998), "100% Blue": (0.1310, 0.0460, 5.9302), "100% Cyan": (0.1465, 0.3446, 73.7300), "100% Magenta": (0.3682, 0.1471, 32.2002), "100% Yellow": (0.4465, 0.5374, 94.0698), }, } # BT.709 共用 sRGB 三原色，做别名指向，避免重复维护 _PRIMARY_XYY_BY_GAMUT["BT.709"] = _PRIMARY_XYY_BY_GAMUT["sRGB"] # 当前激活色域（默认 sRGB），随信号格式切换调用 set_active_gamut() 修改 _ACTIVE_GAMUT = "sRGB" def set_active_gamut(gamut_name): """ 切换当前色域（随信号格式选择调用）。 支持: 'sRGB' / 'BT.709' / 'DCI-P3' / 'BT.2020'。 """ global _ACTIVE_GAMUT if gamut_name not in _PRIMARY_XYY_BY_GAMUT: raise ValueError( f"未知色域: {gamut_name}，可选: {list(_PRIMARY_XYY_BY_GAMUT)}" ) _ACTIVE_GAMUT = gamut_name def get_active_gamut(): """返回当前激活的色域名。""" return _ACTIVE_GAMUT def _current_primaries(): """返回当前色域的原色表。""" return _PRIMARY_XYY_BY_GAMUT[_ACTIVE_GAMUT] # ====================================================================== # 测试流程用名 -> 标准来源 # 彩色块: 映射到 _COLOR_PATCH_XYY 的键 # 灰阶 : 映射到 linear 信号值（Yr = 信号值×100） # 100%原色: 走当前色域的 _PRIMARY_XYY_BY_GAMUT # ====================================================================== _PATCH_NAME_MAP = { "Dark Skin": "dark skin", "Light Skin": "light skin", "Blue Sky": "blue sky", "Foliage": "foliage", "Blue Flower": "blue flower", "Bluish Green": "bluish green", "Orange": "orange", "Purplish Blue": "purplish blue", "Moderate Red": "moderate red", "Purple": "purple", "Yellow Green": "yellow green", "Orange Yellow": "orange yellow", "Blue (Legacy)": "blue", "Green (Legacy)": "green", "Red (Legacy)": "red", "Yellow (Legacy)": "yellow", "Magenta (Legacy)": "magenta", "Cyan (Legacy)": "cyan", } # 灰阶：信号值（线性域目标相对亮度），色度恒为 D65 白点 _GRAYSCALE_SIGNAL = { "White": 1.00, "Gray 80": 0.80, "Gray 65": 0.65, "Gray 50": 0.50, "Gray 35": 0.35, "Black": 0.00, } _SDR_COLOR_PATTERNS = [ ("White", *_rgb(255, 255, 255)), ("Gray 80", *_rgb(230, 230, 230)), ("Gray 65", *_rgb(209, 209, 209)), ("Gray 50", *_rgb(186, 186, 186)), ("Gray 35", *_rgb(158, 158, 158)), ("Dark Skin", *_rgb(115, 82, 66)), ("Light Skin", *_rgb(194, 150, 130)), ("Blue Sky", *_rgb(94, 122, 156)), ("Foliage", *_rgb(89, 107, 66)), ("Blue Flower", *_rgb(130, 128, 176)), ("Bluish Green", *_rgb(99, 189, 168)), ("Orange", *_rgb(217, 120, 41)), ("Purplish Blue", *_rgb(74, 92, 163)), ("Moderate Red", *_rgb(194, 84, 97)), ("Purple", *_rgb(92, 61, 107)), ("Yellow Green", *_rgb(158, 186, 64)), ("Orange Yellow", *_rgb(230, 161, 46)), ("Blue (Legacy)", *_rgb(51, 61, 150)), ("Green (Legacy)", *_rgb(71, 148, 71)), ("Red (Legacy)", *_rgb(176, 48, 59)), ("Yellow (Legacy)", *_rgb(237, 199, 33)), ("Magenta (Legacy)", *_rgb(186, 84, 145)), ("Cyan (Legacy)", *_rgb(0, 133, 163)), ("100% Red", *_rgb(255, 0, 0)), ("100% Green", *_rgb(0, 255, 0)), ("100% Blue", *_rgb(0, 0, 255)), ("100% Cyan", *_rgb(0, 255, 255)), ("100% Magenta", *_rgb(255, 0, 255)), ("100% Yellow", *_rgb(255, 255, 0)), ] # ---------------------------------------------------------------------- # 标准 xy / Yr 解析（统一入口） # ---------------------------------------------------------------------- def _resolve_reference_xy(name): """返回该色块的标准参考 xy。未知则回退 D65。""" if name in _GRAYSCALE_SIGNAL: return (D65_X, D65_Y) if name in _PATCH_NAME_MAP: x, y, _ = _COLOR_PATCH_XYY[_PATCH_NAME_MAP[name]] return (x, y) primaries = _current_primaries() if name in primaries: x, y, _ = primaries[name] return (x, y) return (D65_X, D65_Y) def _resolve_reference_yr(name): """ 返回该色块的标准相对亮度因子 Yr (0~100)。 灰阶: 信号值×100 (linear)。彩色/原色: 光谱或色域 Yr。 无法确定返回 None。 """ if name in _GRAYSCALE_SIGNAL: return _GRAYSCALE_SIGNAL[name] * 100.0 if name in _PATCH_NAME_MAP: return _COLOR_PATCH_XYY[_PATCH_NAME_MAP[name]][2] primaries = _current_primaries() if name in primaries: return primaries[name][2] return None def get_target_xyY(name, white_lv): """ 返回该色块的完整 target (x, y, Y)。 Target Y = white_lv × Yr / 100 （统一规则）。 Yr 不可知时 Y 返回 None，由调用方按实测处理。 """ x, y = _resolve_reference_xy(name) Yr = _resolve_reference_yr(name) if Yr is None or white_lv is None or white_lv <= 0: return (x, y, None) return (x, y, round(white_lv * Yr / 100.0, 4)) # ---------------------------------------------------------------------- # 兼容旧接口 # ---------------------------------------------------------------------- def get_accuracy_reference_y(name, white_lv): """ 返回图表/表格用的参考亮度比例（White=100 缩放）。 现基于标准 Yr 返回真实比例；无标准 Yr 时回退 100。 """ Yr = _resolve_reference_yr(name) if Yr is None or white_lv is None or white_lv <= 0: return 100.0 return round(Yr, 4) # ---------------------------------------------------------------------- # xyY -> XYZ -> Lab（CIE 官方定义） # ---------------------------------------------------------------------- def _xyY_to_XYZ(x, y, Y): """xyY 转 XYZ。y 为 0 时返回全 0，避免除零。""" if y <= 0: return 0.0, 0.0, 0.0 X = (x / y) * Y Z = ((1.0 - x - y) / y) * Y return X, Y, Z def _XYZ_to_lab(X, Y, Z, Xn, Yn, Zn): """ XYZ 转 CIE L*a*b*。 Xn, Yn, Zn 为参考白点的绝对 XYZ（Yn 通常为白场亮度 white_lv）。 """ delta = 6.0 / 29.0 def f(t): if t > delta ** 3: return t ** (1.0 / 3.0) return t / (3.0 * delta ** 2) + 4.0 / 29.0 xr = X / Xn if Xn != 0 else 0.0 yr = Y / Yn if Yn != 0 else 0.0 zr = Z / Zn if Zn != 0 else 0.0 fx, fy, fz = f(xr), f(yr), f(zr) L = 116.0 * fy - 16.0 a = 500.0 * (fx - fy) b = 200.0 * (fy - fz) return L, a, b def _xyY_to_lab(x, y, Y, white_x=D65_X, white_y=D65_Y, white_Y=None): """ xyY 直接转 Lab。 白点默认 D65 色度；white_Y 为白场绝对亮度（用于 L 的归一化基准）。 若 white_Y 为 None，则退化为以 Y=1 归一化（仅相对比较时可用）。 """ if white_Y is None or white_Y <= 0: white_Y = 1.0 X, Y3, Z = _xyY_to_XYZ(x, y, Y) Xn, Yn, Zn = _xyY_to_XYZ(white_x, white_y, white_Y) return _XYZ_to_lab(X, Y3, Z, Xn, Yn, Zn) # ---------------------------------------------------------------------- # CIEDE2000（官方公式） # ---------------------------------------------------------------------- def _delta_e_2000_from_lab(L1, a1, b1, L2, a2, b2, kL=1.0, kC=1.0, kH=1.0): C1 = math.sqrt(a1 ** 2 + b1 ** 2) C2 = math.sqrt(a2 ** 2 + b2 ** 2) C_bar = (C1 + C2) / 2.0 G = 0.5 * (1 - math.sqrt(C_bar ** 7 / (C_bar ** 7 + 25 ** 7))) a1_prime = a1 * (1 + G) a2_prime = a2 * (1 + G) C1_prime = math.sqrt(a1_prime ** 2 + b1 ** 2) C2_prime = math.sqrt(a2_prime ** 2 + b2 ** 2) def calc_hue(a_prime, b): if a_prime == 0 and b == 0: return 0.0 h = math.degrees(math.atan2(b, a_prime)) if h < 0: h += 360.0 return h h1_prime = calc_hue(a1_prime, b1) h2_prime = calc_hue(a2_prime, b2) # ΔL', ΔC' delta_L_prime = L2 - L1 delta_C_prime = C2_prime - C1_prime # Δh'（官方三分支） if C1_prime * C2_prime == 0: delta_h_prime = 0.0 else: dh = h2_prime - h1_prime if abs(dh) <= 180: delta_h_prime = dh elif dh > 180: delta_h_prime = dh - 360.0 else: delta_h_prime = dh + 360.0 delta_H_prime = ( 2.0 * math.sqrt(C1_prime * C2_prime) * math.sin(math.radians(delta_h_prime / 2.0)) ) # 平均值 L_bar_prime = (L1 + L2) / 2.0 C_bar_prime = (C1_prime + C2_prime) / 2.0 # H_bar'（官方分支） if C1_prime * C2_prime == 0: H_bar_prime = h1_prime + h2_prime else: dh_abs = abs(h1_prime - h2_prime) if dh_abs <= 180: H_bar_prime = (h1_prime + h2_prime) / 2.0 elif (h1_prime + h2_prime) < 360: H_bar_prime = (h1_prime + h2_prime + 360.0) / 2.0 else: H_bar_prime = (h1_prime + h2_prime - 360.0) / 2.0 T = ( 1 - 0.17 * math.cos(math.radians(H_bar_prime - 30)) + 0.24 * math.cos(math.radians(2 * H_bar_prime)) + 0.32 * math.cos(math.radians(3 * H_bar_prime + 6)) - 0.20 * math.cos(math.radians(4 * H_bar_prime - 63)) ) delta_theta = 30 * math.exp(-(((H_bar_prime - 275) / 25.0) ** 2)) R_C = 2 * math.sqrt(C_bar_prime ** 7 / (C_bar_prime ** 7 + 25 ** 7)) R_T = -R_C * math.sin(math.radians(2 * delta_theta)) S_L = 1 + (0.015 * (L_bar_prime - 50) ** 2) / math.sqrt( 20 + (L_bar_prime - 50) ** 2 ) S_C = 1 + 0.045 * C_bar_prime S_H = 1 + 0.015 * C_bar_prime * T return math.sqrt( (delta_L_prime / (kL * S_L)) ** 2 + (delta_C_prime / (kC * S_C)) ** 2 + (delta_H_prime / (kH * S_H)) ** 2 + R_T * (delta_C_prime / (kC * S_C)) * (delta_H_prime / (kH * S_H)) ) def calculate_delta_e_2000( measured_x, measured_y, measured_lv, standard_x, standard_y, standard_lv=None, white_lv=None, ): """ 计算 ΔE 2000 色差。 Args: measured_x, measured_y: 测量的 xy 坐标 measured_lv: 测量的亮度（cd/m²） standard_x, standard_y: 标准的 xy 坐标 standard_lv: 标准亮度（cd/m²）；默认与 measured_lv 相同 white_lv: 白场亮度（cd/m²），作为 Lab 的 L 归一化基准； 默认取 measured_lv（仅当不传时退化为相对比较） Returns: float: ΔE 2000 色差值 """ if standard_lv is None: standard_lv = measured_lv if white_lv is None: white_lv = measured_lv L1, a1, b1 = _xyY_to_lab(measured_x, measured_y, measured_lv, white_Y=white_lv) L2, a2, b2 = _xyY_to_lab(standard_x, standard_y, standard_lv, white_Y=white_lv) return _delta_e_2000_from_lab(L1, a1, b1, L2, a2, b2) def calculate_accuracy_delta_e_2000( patch_name, measured_x, measured_y, measured_lv, white_lv ): """ 色准测试专用 ΔE2000 标准 xy 来自光谱积分/色域定义（随当前色域）； 目标 Y 取实测 Y（同亮度下比较色度差异）。 L 的归一化基准使用白场亮度 white_lv。 """ standard_x, standard_y = _resolve_reference_xy(patch_name) return calculate_delta_e_2000( measured_x, measured_y, measured_lv, standard_x, standard_y, standard_lv=measured_lv, white_lv=white_lv, ) def calculate_color_accuracy(measured, standard): """计算色差（简化版，xy 欧氏距离 × 1000）""" delta_E = {} for color in measured.keys(): dx = measured[color][0] - standard[color][0] dy = measured[color][1] - standard[color][1] delta_E[color] = np.sqrt(dx * dx + dy * dy) * 1000 return delta_E def get_accuracy_color_standards(test_type=None): """返回色准标准（patch 名称 -> 参考 xy，随当前色域）。""" del test_type return {name: _resolve_reference_xy(name) for name, _, _, _ in _SDR_COLOR_PATTERNS}