Updated the rs_launch.py params

README.md

@@ -465,6 +465,11 @@ The following post processing filters are available:
  - ```hdr_merge```: Allows depth image to be created by merging the information from 2 consecutive frames, taken with different exposure and gain values.
   - The way to set exposure and gain values for each sequence in runtime is by first selecting the sequence id, using the `depth_module.sequence_id` parameter and then modifying the `depth_module.gain`, and `depth_module.exposure`.
   - To view the effect on the infrared image for each sequence id use the `filter_by_sequence_id.sequence_id` parameter.
+  - To initialize these parameters in start time use the following parameters:
+    - `depth_module.exposure.1`
+    - `depth_module.gain.1`
+    - `depth_module.exposure.2`
+    - `depth_module.gain.2`
   - For in-depth review of the subject please read the accompanying [white paper](https://dev.intelrealsense.com/docs/high-dynamic-range-with-stereoscopic-depth-cameras).
 
   - The following filters have detailed descriptions in : https://github.com/IntelRealSense/librealsense/blob/master/doc/post-processing-filters.md

realsense2_camera/launch/rs_launch.py

@@ -50,6 +50,10 @@
                            {'name': 'depth_module.gain',            'default': '16', 'description': 'Depth module manual gain value'},
                            {'name': 'depth_module.hdr_enabled',     'default': 'false', 'description': 'Depth module hdr enablement flag. Used for hdr_merge filter'},
                            {'name': 'depth_module.enable_auto_exposure', 'default': 'true', 'description': 'enable/disable auto exposure for depth image'},
+                           {'name': 'depth_module.exposure.1',      'default': '7500', 'description': 'Depth module first exposure value. Used for hdr_merge filter'},
+                           {'name': 'depth_module.gain.1',          'default': '16', 'description': 'Depth module first gain value. Used for hdr_merge filter'},
+                           {'name': 'depth_module.exposure.2',      'default': '1', 'description': 'Depth module second exposure value. Used for hdr_merge filter'},
+                           {'name': 'depth_module.gain.2',          'default': '16', 'description': 'Depth module second gain value. Used for hdr_merge filter'},
                            {'name': 'enable_confidence',            'default': 'true', 'description': 'enable confidence'},
                            {'name': 'enable_sync',                  'default': 'false', 'description': "'enable sync mode'"},
                            {'name': 'enable_rgbd',                  'default': 'false', 'description': "'enable rgbd topic'"},