RANSAC
隨機取樣一致(RANSAC)以最少數量的資料點實例化模型,再收集誤差容許範圍內的一致集合;若一致集合大小達門檻 t,就在該集合上以最小平方法重新估計,否則重新抽樣,試驗次數用盡時採用最大一致集合或宣告失敗(Sec. II)。論文推導試驗次數期望值 E(k) = w^(-n) 與達成信心 z 所需的 k。主要應用為由已知位置地標的影像求相機投影中心的定位問題(LDP),給出 P3P 最多四解的封閉形式解,並證明共面 P4P 與一般位置 P6P 有唯一解;原文不涉及點雲配準。點雲配準中的用法依 FGR 論文 Sec. 1 的描述,TEASER 論文 Sec. I 註腳指出其執行時間隨離群比例呈指數成長。
本頁內容
Hypothesize-and-verify robust fitting originally applied to the Location Determination Problem; in registration it is the standard coarse-alignment baseline whose runtime grows exponentially with the outlier ratio (per Yang et al., 2021 Sec. I, footnote 1).
技術屬性
欄位內容為文獻擷取紀錄的原文用語(英文),以原文為據;「未查證」表示本研究尚未讀到該資訊,不代表該方法不具備此能力。
| 感測輸入 | aerial photograph from about 4,000 ft with a 6 in. lens, digitized on a 2,000 x 2,000 grid (about 2 ft per pixel)、synthetic landmark-to-image correspondences |
|---|---|
| 原文測試平台 | simulation、airborne camera (aerial image) |
| 狀態估計 | hypothesize-and-verify: randomly select a minimal subset of n data points to instantiate the model, collect the consensus set within an error tolerance, and if its size reaches threshold t refit the model (e.g., least squares) on the consensus set; otherwise resample; after k trials use the largest consensus set or fail; expected trials E(k) = w^(-n), and k = log(1-z)/log(1-w^n) for confidence z |
| 資料關聯 | original: landmark-to-image correspondences from error-prone feature detectors (cross correlation in the aerial test); consensus judged with image-plane error ellipses derived from perturbing the three selected points; point cloud registration use with putative 3D correspondences is a later application (secondary) |
| 時間表示 | 不適用 |
| 去畸變 | 不適用 |
| 迴圈閉合 | none |
| 全域最佳化 | none |
| 地圖表示 | 不適用 |
| 先驗資訊 | none |
| 可輸出幾何 | in the original LDP application: 3-D location of the centre of perspective with an error estimate, and the spatial orientation of the image plane |
| 計算需求 | about 1 s per camera position considered for the synthetic LDP program; hardware not reported |
使用設備
原文使用的感測器、運算硬體與載具(equipment)。型號保留原文寫法,連結到設備頁中同一型號的歸併名稱;角色依原文用途分為方法輸入、資料集感測器、執行運算平台、參考或真值量測(reference or ground truth)與比較對象設備。
| 類別 | 型號(原文寫法) | 角色 | 資料集 | 原文規格 | 出處 |
|---|---|---|---|---|---|
| 相機 | aerial camera with 6 in. lens | 方法輸入 | 未標示 | image taken from approximately 4,000 ft; digitized on a 2,000 x 2,000 pixel grid, about 2 ft per pixel ground resolution | (Fischler & Bolles, 1981, Sec. IV.E) |
作者報告的優勢與限制
優勢
- interprets and smooths data containing a significant percentage of gross errors (abstract)
- in an LDP with 5 gross errors among 20 correspondences a least-squares pruning heuristic kept 3 gross errors, while RANSAC found the correct solution on the second triple with none (Sec. IV.C)
- in 50 synthetic LDPs no gross error entered the final consensus set (Sec. IV.D, Table I)
- real aerial image: consensus of 17 on the first triple, extended to all 22 good correspondences (Sec. IV.E)
- closed-form P3P solution with up to four real solutions; unique solutions for coplanar P4P and general-position P6P (Sec. III, Appendices A-B)
限制
- runtime grows exponentially with outlier ratio and performs poorly at high outlier rates (Yang et al., 2021 Sec. I, secondary)
- three parameters must be set: error tolerance, number of trials and consensus threshold t (Sec. II)
- expected trials rise as w^(-n), for example 16 for w = 0.5 and n = 4 but 625 for w = 0.2 and n = 4, and SD(k) is about equal to E(k), so two to three times E(k) trials may be needed (Sec. II.B)
- multiple physically real solutions can exist for P3P, P4P and P5P, so a sample may yield ambiguous poses (Sec. III)
營建工程相關證據
原文未報告
原文驗證環境:模擬
報告的性能數據
以下是原文作者報告的性能數值(author-reported results),不是本研究重新量測的結果。每張圖只並列同一個比較組(comparison group,同一張表、同一組實驗設定)內的方法;不同比較組之間的數值不可直接比較,也不構成排名。
本方法共出現在 11 個比較組,合計 75 筆紀錄。以下列出本方法紀錄最多的 4 組,其餘 7 組列在最後,並連到性能比較頁。
Fischler & Bolles, 1981 · Table I 本方法 30 筆
表格設定(擷取紀錄原文):Ten typical of 50 synthetic LDPs, 30 landmark-to-image correspondences each; gross errors at least 10 px off, good ones with 1 px std; RANSAC avoided gross errors in the final consensus set in all problems (Fischler & Bolles, 1981, Table I)
No. of correspondences in final consensus set,50 synthetic location determination problems · typical problem 1 (w=0.8)
這張表在此指標與資料序列只列出本方法一筆,沒有可並列的其他方法,因此不畫圖,數值與出處見下表。這是 Fischler & Bolles, 1981 在此表設定下報告的數值(author-reported results),不代表方法在其他資料或設定下的表現。
| 方法(原文寫法) | 報告值 | 出處 |
|---|---|---|
| RANSAC/LD本方法原文提出 | 19 count | (Fischler & Bolles, 1981, Table I) |
Yang et al., 2021 · Table II 本方法 18 筆
表格設定(擷取紀錄原文,這些數值分屬表中不同部分):(Yang et al., 2021, Table II)
- 3DMatch test scenes, 3DSmoothNet correspondences, success = rotation error < 10 deg and translation error < 30 cm; beta = 5 cm; CERT = subset certified with sub-optimality gap 3%; Xeon Platinum 8259CL, 12 threads
- Same setting as other Table II rows
percentage of correct registration results,3DMatch · Kitchen
只並列這張表在相同設定下報告的方法;以「本方法:」開頭者為本頁方法。失敗、未執行與未報告以標記呈現,不是 0。
按 Tab 進入圖表後,用上下方向鍵逐一瀏覽各類別,Esc 關閉提示框;也可開啟表格檢視閱讀全部數值。
這些是 Yang et al., 2021 在此表設定下報告的數值(author-reported results),只能在同一個比較組內對照,不代表方法在其他資料或設定下的表現。
資料來源作者報告值(Yang et al., 2021, Table II)
| 方法(原文寫法) | 報告值 | 出處 |
|---|---|---|
| RANSAC-1K本方法 | 91.3% | (Yang et al., 2021, Table II) |
| RANSAC-10K本方法 | 97.2% | (Yang et al., 2021, Table II) |
| TEASER++原文提出 | 98.6% | (Yang et al., 2021, Table II) |
| TEASER++ (CERT)原文提出 | 99.4% | (Yang et al., 2021, Table II) |
Fischler & Bolles, 1981 · Text Sec. IV.E 本方法 8 筆
資料集與序列real aerial image · single image
表格設定(擷取紀錄原文):Aerial image from about 4,000 ft with 6 in. lens, digitized 2,000 x 2,000 px (about 2 ft per px); 25 landmarks found by cross correlation, 3 gross errors (Fischler & Bolles, 1981, Text Sec. IV.E)
consensus set size found on the first triple,real aerial image · single image
這張表在此指標與資料序列只列出本方法一筆,沒有可並列的其他方法,因此不畫圖,數值與出處見下表。這是 Fischler & Bolles, 1981 在此表設定下報告的數值(author-reported results),不代表方法在其他資料或設定下的表現。
| 方法(原文寫法) | 報告值 | 出處 |
|---|---|---|
| RANSAC/LD本方法原文提出 | 17 count | (Fischler & Bolles, 1981, Sec. IV.E) |
Zhang et al., 2024b · Table 1 本方法 6 筆
資料集與序列ISPRS benchmark on indoor modelling · Models 01-05 (250 samples)
表格設定(擷取紀錄原文):Coarse registration on 250 samples (50 per model) with random rigid perturbations (roll and pitch within 30 deg, yaw within 180 deg, translation within 10 m); only successful results with RE < 45 deg and TE < 10 m are included; A50, A75 and A95 quantiles of rotation and translation error against the benchmark alignment (Zhang et al., 2024b, Table 1)
RE_50, rotation error 50th percentile,ISPRS benchmark on indoor modelling · Models 01-05 (250 samples)
只並列這張表在相同設定下報告的方法;以「本方法:」開頭者為本頁方法。失敗、未執行與未報告以標記呈現,不是 0。
按 Tab 進入圖表後,用上下方向鍵逐一瀏覽各類別,Esc 關閉提示框;也可開啟表格檢視閱讀全部數值。
這些是 Zhang et al., 2024b 在此表設定下報告的數值(author-reported results),只能在同一個比較組內對照,不代表方法在其他資料或設定下的表現。
資料來源作者報告值(Zhang et al., 2024b, Table 1)
| 方法(原文寫法) | 報告值 | 出處 |
|---|---|---|
| GMMTree (initialised with FPFH-RANSAC) | 4.466 deg | (Zhang et al., 2024b, Table 1) |
| FilterReg (initialised with FPFH-RANSAC) | 3.59 deg | (Zhang et al., 2024b, Table 1) |
| GO-ICP | 4.178 deg | (Zhang et al., 2024b, Table 1) |
| Super4PCS | 2.208 deg | (Zhang et al., 2024b, Table 1) |
| FGR | 27.139 deg | (Zhang et al., 2024b, Table 1) |
| RANSAC (FPFH features)本方法 | 5.477 deg | (Zhang et al., 2024b, Table 1) |
| RMMG | 1.673 deg | (Zhang et al., 2024b, Table 1) |
| PLADE | 0.424 deg | (Zhang et al., 2024b, Table 1) |
| DCP | 34.865 deg | (Zhang et al., 2024b, Table 1) |
| PointNetLK | 11.741 deg | (Zhang et al., 2024b, Table 1) |
| Ours (primitive-level coarse registration)原文提出 | 0.272 deg | (Zhang et al., 2024b, Table 1) |
其他比較組
來源
Fischler & Bolles, 1981
(1981)Random sample consensusCommunications of the ACM, 24(6):381-395
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