colmap · ahojnnes · Jun 12, 2025 · Apr 25, 2025 · Apr 25, 2025 · May 20, 2025
diff --git a/src/colmap/controllers/image_reader.cc b/src/colmap/controllers/image_reader.cc
@@ -156,11 +156,22 @@ ImageReader::Status ImageReader::Next(Rig* rig,
   //////////////////////////////////////////////////////////////////////////////
 
   if (mask && !options_.mask_path.empty()) {
-    const std::string mask_path =
+    std::string mask_path =
         JoinPaths(options_.mask_path, image->Name() + ".png");
     if (!ExistsFile(mask_path)) {
-      LOG(ERROR) << "Mask at " << mask_path << " does not exist.";
-      return Status::MASK_ERROR;
+      bool exists_mask = false;
+      if (HasFileExtension(image->Name(), ".png")) {
+        std::string alt_mask_path =
+            JoinPaths(options_.mask_path, image->Name());
+        if (ExistsFile(alt_mask_path)) {
+          mask_path = std::move(alt_mask_path);
+          exists_mask = true;
+        }
+      }
+      if (!exists_mask) {
+        LOG(ERROR) << "Mask at " << mask_path << " does not exist.";
+        return Status::MASK_ERROR;
+      }
     }
     if (!mask->Read(mask_path, false)) {
       LOG(ERROR) << "Failed to read invalid mask file at: " << mask_path;

diff --git a/src/colmap/mvs/fusion.cc b/src/colmap/mvs/fusion.cc
@@ -339,9 +339,13 @@ void StereoFusion::InitFusedPixelMask(int image_idx,
                                       size_t height) {
   Bitmap mask;
   Mat<char>& fused_pixel_mask = fused_pixel_masks_.at(image_idx);
-  const std::string mask_path =
-      JoinPaths(options_.mask_path,
-                workspace_->GetModel().GetImageName(image_idx) + ".png");
+  const std::string mask_image_name =
+      workspace_->GetModel().GetImageName(image_idx);
+  std::string mask_path =
+      JoinPaths(options_.mask_path, mask_image_name + ".png");
+  if (!ExistsFile(mask_path) && HasFileExtension(mask_image_name, ".png")) {
+    mask_path = JoinPaths(options_.mask_path, mask_image_name);
+  }
   fused_pixel_mask = Mat<char>(width, height, 1);
   if (!options_.mask_path.empty() && ExistsFile(mask_path) &&
       mask.Read(mask_path, false)) {

diff --git a/src/colmap/util/file.h b/src/colmap/util/file.h
@@ -82,7 +82,7 @@ void FileCopy(const std::string& src_path,
               const std::string& dst_path,
               CopyType type = CopyType::COPY);
 
-// Check if the path points to an existing directory.
+// Check if the path points to an existing file.
 bool ExistsFile(const std::string& path);
 
 // Check if the path points to an existing directory.