进一步优化

libs/MVS/SceneTexture.cpp

@@ -766,6 +766,8 @@ public:
     unsigned nTextureSizeMultiple,
     Pixel8U colEmpty,
     Mesh::Image8U3Arr& outTextures);
+	void GlobalPatchColorAlignment(Image8U3& atlas, int textureSize);
+
 	// ========== 辅助函数 ==========
 
 	// 双线性采样（适配 SEACAVE::TImage<Pixel8U>）
@@ -14370,6 +14372,132 @@ void MeshTexture::FillTextureHoles(std::vector<Image8U3>& textures, Pixel8U colE
     DEBUG_EXTRA("Hole filling completed");
 }
 
+// ===== 全局 Patch 颜色对齐 =====
+// 在 seam edge 上采样两侧 patch 的颜色，求解每个 patch 的偏移量
+void MeshTexture::GlobalPatchColorAlignment(Image8U3& atlas, int textureSize)
+{
+    if (rcSeamEdges.empty() || rcPatches.empty()) return;
+    
+    DEBUG_EXTRA("Global patch color alignment...");
+    TD_TIMER_START();
+
+    const int NP = (int)rcPatches.size();
+    
+    // 收集约束：每条 seam edge 两侧 patch 在边界上的颜色差
+    struct Constraint { int pa, pb; Color diff; };
+    std::vector<Constraint> constraints;
+    constraints.reserve(rcSeamEdges.size());
+
+    for (const auto& e : rcSeamEdges) {
+        if (e.rcPatchID0 >= NP || e.rcPatchID1 >= NP) continue;
+        const RCPatch& patchA = rcPatches[e.rcPatchID0];
+        const RCPatch& patchB = rcPatches[e.rcPatchID1];
+        
+        // 在重叠区域采样
+        cv::Rect overlap = patchA.rect & patchB.rect;
+        if (overlap.width < 2 || overlap.height < 2) continue;
+        
+        int samples = 0;
+        Color sumA(0,0,0), sumB(0,0,0);
+        
+        for (int y = overlap.y; y < overlap.y + overlap.height && samples < 100; ++y) {
+            for (int x = overlap.x; x < overlap.x + overlap.width && samples < 100; ++x) {
+                if (x < 0 || x >= textureSize || y < 0 || y >= textureSize) continue;
+                const Pixel8U& pxA = atlas(y, x);
+                if (pxA[0]==0 && pxA[1]==0 && pxA[2]==0) continue;
+                sumA[0] += pxA[2]; sumA[1] += pxA[1]; sumA[2] += pxA[0]; // RGB
+                // 从 patchB 的对应位置采样
+                const Pixel8U& pxB = atlas(y, x);
+                sumB[0] += pxB[2]; sumB[1] += pxB[1]; sumB[2] += pxB[0];
+                samples++;
+            }
+        }
+        if (samples < 5) continue;
+        
+        Color avgA = sumA / (float)samples;
+        Color avgB = sumB / (float)samples;
+        constraints.push_back(Constraint{e.rcPatchID0, e.rcPatchID1, avgB - avgA});
+    }
+    
+    if (constraints.empty()) {
+        DEBUG_EXTRA("GlobalPatchColorAlignment: no constraints, skip");
+        return;
+    }
+
+    const int rows = (int)constraints.size();
+    
+    // 构建稀疏矩阵 A 和 b
+    std::vector<Eigen::Triplet<float>> triplets;
+    triplets.reserve(rows * 2 + NP); // 约束 + 正则化
+    Eigen::VectorXf bR(rows), bG(rows), bB(rows);
+    
+    for (int i = 0; i < rows; ++i) {
+        triplets.emplace_back(i, constraints[i].pa, -1.0f);
+        triplets.emplace_back(i, constraints[i].pb,  1.0f);
+        bR(i) = constraints[i].diff[0]; // R
+        bG(i) = constraints[i].diff[1]; // G
+        bB(i) = constraints[i].diff[2]; // B
+    }
+    
+    // 正则化：所有 patch 的偏移量尽量小（Tikhonov）
+    const float lambda = 0.1f;
+    for (int i = 0; i < NP; ++i) {
+        triplets.emplace_back(rows + i, i, lambda);
+    }
+    
+    Eigen::SparseMatrix<float> A(rows + NP, NP);
+    A.setFromTriplets(triplets.begin(), triplets.end());
+    
+	// 求解
+    Eigen::VectorXf xR, xG, xB;
+    {
+        // ★ 转稠密，避免 Sparse LDLT 的 lpNorm bug ★
+        Eigen::MatrixXf A_dense = A;  // Sparse → Dense
+        Eigen::MatrixXf AtA = A_dense.transpose() * A_dense;
+        
+        // 加对角阻尼（1e-6），保证正定可逆
+        const int N = A_dense.cols();
+        for (int i = 0; i < N; ++i) AtA(i, i) += 1e-6f;
+        
+        Eigen::VectorXf AtbR = A_dense.transpose() * bR;
+        Eigen::VectorXf AtbG = A_dense.transpose() * bG;
+        Eigen::VectorXf AtbB = A_dense.transpose() * bB;
+        
+        Eigen::LDLT<Eigen::MatrixXf> ldlt(AtA);
+        if (ldlt.info() != Eigen::Success) {
+            DEBUG_EXTRA("GlobalPatchColorAlignment: LDLT failed");
+            return;
+        }
+        xR = ldlt.solve(AtbR);
+        xG = ldlt.solve(AtbG);
+        xB = ldlt.solve(AtbB);
+    }
+    
+    // 应用：对每个 patch 的像素加上偏移（加性，限制幅度）
+    const float maxAdj = 30.0f; // 8-bit 空间最大偏移
+    #pragma omp parallel for
+    for (int i = 0; i < NP; ++i) {
+        const RCPatch& patch = rcPatches[i];
+        float adjR = std::max(-maxAdj, std::min(maxAdj, xR(i)));
+        float adjG = std::max(-maxAdj, std::min(maxAdj, xG(i)));
+        float adjB = std::max(-maxAdj, std::min(maxAdj, xB(i)));
+        
+        for (int y = patch.rect.y; y < patch.rect.y + patch.rect.height; ++y) {
+            for (int x = patch.rect.x; x < patch.rect.x + patch.rect.width; ++x) {
+                if (x < 0 || x >= textureSize || y < 0 || y >= textureSize) continue;
+                Pixel8U& px = atlas(y, x);
+                if (px[0]==0 && px[1]==0 && px[2]==0) continue;
+                // BGR 存储顺序
+px[2] = (uint8_t)CLAMP(px[2] + adjR, 0.f, 255.f); // R
+px[1] = (uint8_t)CLAMP(px[1] + adjG, 0.f, 255.f); // G
+px[0] = (uint8_t)CLAMP(px[0] + adjB, 0.f, 255.f); // B
+            }
+        }
+    }
+    
+    DEBUG_EXTRA("Global alignment done: %d constraints (%s)", rows, TD_TIMER_GET_FMT().c_str());
+}
+
 // ============================================================
 // 3. RC 风格光栅化主函数（含接缝优化）
 // ============================================================
@@ -14504,6 +14632,8 @@ bool MeshTexture::RasterizeVirtualFaces(
     }
     DEBUG_EXTRA("Created %zu RC patches", rcPatches.size());
 
+	GlobalPatchColorAlignment(atlas, textureSize);
+
     // 5/6/7. 接缝
     BuildSeamEdgesFromRCPatches();
     if (!seamEdges.empty()) {