Quick build fix (#29)

Author: lucasreljic

deep_tools/camera_sync/CMakeLists.txt

@@ -24,7 +24,6 @@ find_package(rclcpp_lifecycle REQUIRED)
 find_package(rclcpp_components REQUIRED)
 find_package(lifecycle_msgs REQUIRED)
 find_package(sensor_msgs REQUIRED)
-find_package(message_filters REQUIRED)
 find_package(image_transport REQUIRED)
 find_package(cv_bridge REQUIRED)
 find_package(deep_msgs REQUIRED)
@@ -46,7 +45,6 @@ target_link_libraries(multi_camera_sync_component
   rclcpp_components::component_manager
   lifecycle_msgs::lifecycle_msgs__rosidl_typesupport_cpp
   sensor_msgs::sensor_msgs__rosidl_typesupport_cpp
-  message_filters::message_filters
   image_transport::image_transport
   cv_bridge::cv_bridge
   deep_msgs::deep_msgs__rosidl_typesupport_cpp

deep_tools/camera_sync/DEVELOPING.md

@@ -17,11 +17,6 @@ The Macro:
 #endif
 ```
 
-### 2. Message Filters Synchronization Limitation
-**Problem**: `message_filters::Synchronizer` requires compile-time known number of topics.
-- **Limitation**: Cannot dynamically sync N cameras - must handle 2-6 cameras with separate synchronizers
-- **Implementation**: Switch statement creates different sync policies for each camera count
-
 ## Architecture Notes
 - **Component-only**: No standalone executable - use component loading only which is ideal to allow for IPC (zero-copy)
 - **Dual Mode**: Supports both raw and compressed image synchronization

deep_tools/camera_sync/README.md

@@ -1,10 +1,10 @@
 # Multi-Camera Synchronization Node
 
-A ROS2 node that uses message filters to time-synchronize N camera image messages, supporting both compressed and raw images.
+A ROS2 node that uses custom buffering to time-synchronize N camera image messages, supporting both compressed and raw images.
 
 ## Features
 
-- **Flexible camera count**: Supports 2-6 cameras simultaneously
+- **Flexible camera count**: Supports 2-12 cameras simultaneously
 - **Image format support**: Works with both `sensor_msgs/Image` (raw) and `sensor_msgs/CompressedImage`
 - **Configurable synchronization**: Adjustable time tolerance and queue sizes
 - **Real-time monitoring**: Synchronization statistics and rate monitoring
@@ -18,7 +18,7 @@ A ROS2 node that uses message filters to time-synchronize N camera image message
 | `camera_names` | string[] | `[]` | Names for cameras (auto-generated if empty) |
 | `use_compressed` | bool | `false` | Use compressed images instead of raw RGB |
 | `sync_tolerance_ms` | double | `50.0` | Max time difference for sync (milliseconds) |
-| `queue_size` | int | `10` | Message filter queue size |
+| `queue_size` | int | `10` | Buffer queue size |
 | `publish_sync_info` | bool | `true` | Publish synchronization statistics |
 
 ## Usage
@@ -35,10 +35,10 @@ All configuration changes can be passed through CLI. Here are some example argum
 
 ## How It Works
 
-The node uses ROS2 message filters with approximate time synchronization policy to match images from multiple cameras based on their timestamps. Key components:
+The node uses ROS2 buffers with approximate time synchronization policy to match images from multiple cameras based on their timestamps. Key components:
 
 1. **Message Subscribers**: Creates subscribers for each camera topic
-2. **Synchronizer**: Uses `message_filters::sync_policies::ApproximateTime` to match messages
+2. **Synchronizer**: Stores buffers from first subscriber and matches with other subscribers within timestamp sync tolerance to match messages
 3. **Callback & Publishing**: Creates MultiImage/MultiImageCompressed msgs with timestamp to batch the camera images together
 4. **Statistics**: Tracks synchronization rate and timing spread
 
@@ -67,7 +67,6 @@ Example log output:
 
 - `rclcpp` - ROS2 C++ client library
 - `sensor_msgs` - Standard sensor message types
-- `message_filters` - Time synchronization utilities
 - `image_transport` - Efficient image transmission
 
 ## Limitations

deep_tools/camera_sync/package.xml

@@ -12,7 +12,6 @@
   <depend>rclcpp_lifecycle</depend>
   <depend>lifecycle_msgs</depend>
   <depend>sensor_msgs</depend>
-  <depend>message_filters</depend>
   <depend>image_transport</depend>
   <depend>cv_bridge</depend>
   <depend>deep_msgs</depend>

deep_tools/camera_sync/src/multi_camera_sync_node.cpp

@@ -430,7 +430,7 @@ void MultiCameraSyncNode::tryPublishSyncedRawImages()
   // Publish synced images
   RCLCPP_DEBUG(this->get_logger(), "Publishing synced raw images (sync count: %ld)", ++sync_count_);
   processSynchronizedImages(timestamps);
-  auto raw_msg = createMultiImageMessage<sensor_msgs::msg::Image, deep_msgs::msg::MultiImageRaw>(synced_images);
+  auto raw_msg = createMultiImageMessage<sensor_msgs::msg::Image, deep_msgs::msg::MultiImage>(synced_images);
   multi_image_raw_pub_->publish(raw_msg);
 }
 
@@ -534,7 +534,7 @@ void MultiCameraSyncNode::tryPublishSyncedCompressedImages()
   RCLCPP_DEBUG(this->get_logger(), "Publishing synced compressed images (sync count: %ld)", ++sync_count_);
   processSynchronizedImages(timestamps);
   auto compressed_msg =
-    createMultiImageMessage<sensor_msgs::msg::CompressedImage, deep_msgs::msg::MultiImage>(synced_images);
+    createMultiImageMessage<sensor_msgs::msg::CompressedImage, deep_msgs::msg::MultiImageCompressed>(synced_images);
   multi_image_compressed_pub_->publish(compressed_msg);
 }