watermedia op• 資料種類:rgbimage × image2d × image2d → table
• 呼叫: import fullseye as fs; fs.ledger.underwater_image(image, depth_map_m, distance_map_m, water_type='jerlov_I', wavelengths_um=None, illumination='daylight', backscatter=True, apply_ambient=False, beta_b_ratio=1.0, backscatter_ratio=0.02) -> 'dict'(要直接呼叫實作,import watermedia; watermedia.underwater_image(image, depth_map_m, distance_map_m, water_type='jerlov_I', wavelengths_um=None, illumination='daylight', backscatter=True, apply_ambient=False, beta_b_ratio=1.0, backscatter_ratio=0.02) -> 'dict';從台帳取用則 opsoptics.get("underwater_image"))
• GPU:無(僅 CPU 參考實作)
透過水記錄的場景影像(修訂版 Jaffe–McGlamery 模型)-> 字典。
> 以下的詳細說明為原文 —— 摘要與標題已翻譯。
Following Akkaynak & Treibitz (2018) the recorded image is I = J exp(-beta_D r) + B_inf (1 - exp(-beta_B r)): the direct signal J of the object attenuated along the camera-object distance r with a wavelength-dependent coefficient, plus backscatter, the veiling light B_inf that builds up along the same path with its own coefficient. image is (H, W, K), non-negative: the appearance of the object at zero distance, per band (K = 3 is RGB with the effective wavelengths 0.61 / 0.54 / 0.465 um, other K need wavelengths_um). depth_map_m is the depth of the scene below the surface and distance_map_m the distance to the camera, each (H, W) or a scalar. beta_D is the diffuse attenuation Kd of water_attenuation (used as the attenuation along the line of sight, an approximation that Akkaynak & Treibitz show to depend on range) and beta_B = beta_b_ratio beta_D. The veiling light is the single-scattering value B_inf = E(z) b_b / (2 c) with b_b = backscatter_ratio b and E(z) = E_0 exp(-Kd z) the daylight left at the depth (an assumption, not a measurement). illumination is "daylight" (flat relative spectrum 1) or a (K,) relative spectrum at the surface. With apply_ambient the object is also dimmed by the ambient light at its depth, J = image E(z); without it image is taken as it already is at the object, so that distance 0 returns it exactly. backscatter=False leaves pure Beer-Lambert. The table has image (the recording), direct, backscatter, transmission (exp(-beta_D r)), beta_D, beta_B, veiling_light (H, W, K), ambient (E(z)/E_0), wavelengths_um and, for RGB, red_to_blue_kd_ratio. Non-finite or negative inputs are refused.
optics 的每個運算子都先檢驗輸入再計算(不讓任何東西無聲通過):
• 單位寫進參數名 —— _mm / _um / _deg / _mrad。把 mm 和 µm 弄混不會當掉,而是給出「看似合理卻是錯的答案」,所以用命名來防。這裡絕不從數值大小去猜單位。
• 字串一律 ValueError —— float('50') 會成功,於是未解析的設定值會被當成長度混進來(實測:thin_lens('50', '200') 曾回傳看似合理的 66.667 mm)。bool 也按 True == 1 的隱式提升拒絕。
• complex / masked array 一律 ValueError(僅接受實數槽位;拒絕無聲丟棄虛部或剝掉遮罩)。所有輸入中的 NaN/Inf 一律 ValueError。但已宣告的缺測除外:bottle_fit_from_pattern 的 u_map 以 NaN 接收未能測得的像素(∞ 仍被拒絕)。
• 逐項點名拒絕除零及其近親:焦距 0、曲率半徑 0、折射率 <= 0、全不透明光闌(全為 0,正規化變成 0/0)、總和 <= 0 的 PSF、S0 = 0 的 Stokes 向量、物體位於前焦點(像在無窮遠)。
• 只有兩個運算子會回傳非有限值,而且都寫進了契約:depth_of_field 在超焦距以外回傳 far_mm = inf(這正是超焦距的定義),gaussian_beam 在束腰處回傳 wavefront_radius_mm = inf(平面波前的曲率半徑)。兩者都同時回傳一個有限的夥伴(far_is_infinite / curvature_per_mm)。除此之外的無聲 NaN/Inf 都在內部檢出並 ValueError ——「float64 溢位了」和「答案是無窮大」是兩種不同的主張,不能拿後者的臉去交付前者。但已宣告的缺測除外:bottle_background_map 對光線不可用的像素(全反射等)在 u_mm 中回傳 NaN,並同時回傳 valid 遮罩和數量。
• 尺寸上限:生成網格受 optics.MAX_GRID(4096)限制,傳入的場/PSF/光闌受 optics.MAX_FIELD_ELEMENTS(2^24),ABCD 元件序列受 optics.MAX_SYSTEM_ELEMENTS(1024),Zernike 受 MAX_ZERNIKE_TERMS(512)/ MAX_ZERNIKE_ORDER(40)/ MAX_ZERNIKE_BASIS(2^25)。以 fail-closed 堵住「小參數引發巨大內部配置」的路徑(實測:n_max=40 × 4096² 需要 108 GB)。
• 物理上不可能的狀態同樣拒絕:偏振度 > 1 的 Stokes 向量、負穿透率、負強度、n-|m| 為奇數等非法 Zernike 指標。
• 範例資料目錄(下載 URL / 授權) —— 2-D 用 skimage.data(BSD/公有領域)加合成圖,3-D 給出真實資料源(Stanford/PDS 等)的下載 URL。
• 運算子來歷與參考文獻 —— 該運算子族所依據的研究/方法出處。
• 演算法的正典(作者、年份)與用途見上面的族使用指南。
• poc_water_transparent_media — py -3.11 examples/poc_water_transparent_media.py
table 作為輸入)abcd_matrix · wavefront_stats · sfr_from_edge · paraxial_trace · seidel_coefficients · spot_stats · tolerance_analysis · wavefront_from_opd
watermedia)ocean_spectrum · ocean_height_field · fresnel_water_air · snell_window · refracted_view · water_attenuation · phase_function_hg · scattering_phase_petzold
*Provenance: watermedia.py — OPTICS 運算子登記表。本條目由 tools/opdocs.py md 自動產生(請勿手動編輯)。*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.