CocoAnnotationsWriter generating different categories across breaking "append_to_existing_output" option

[travis575757]

I am trying to run CocoAnnotationsWriter repeatedly to produce a dataset, however sometimes an exception is raised "The existing coco annotations file contains different categories/objects than the current scene. Merging the two lists is not implemented yet" even though I haven't changed the dataset. I would expect that running the config would generate the same categories as without this functionality there wouldn't be much use is using "append_to_existing_output".

If this is expected behavior what should I do to prevent this from happening? I would like to execute this config N times and get N*number_of_samples annotated images contained in ./testing_multi/output/coco_data/coco_annotations.json where number_of_samples comes from the argument of camera.CameraSampler. See the config below for where these values are coming from.

Reproduce

To reproduce go into the config of the coco_annotations example and replace the camera.CameraLoader with

    {
      "module": "camera.CameraSampler",
      "config": {
        "cam_poses": [
          {
            "number_of_samples": 2,
            "location": {
              "provider":"sampler.Uniform3d",
              "max":[10, 10, 8],
              "min":[-10, -10, 12]
            },
            "rotation": {
              "format": "look_at",
              "value": {
                "provider": "getter.POI"
              },          
              "inplane_rot": {
                "provider": "sampler.Value",
                "type": "float",
                "min": -0.7854,
                "max": 0.7854
              }
            }
          }
        ]
      }
    },

and also enable appending annotations

    {
      "module": "writer.CocoAnnotationsWriter",
      "config": {
        "append_to_existing_output": True,
      }
    }

My full config is below, I've also hardcoded the arguments used in the example

# Args: <cam_file> <obj_file> <output_dir>
{
  "version": 3,
  "setup": {
    "blender_install_path": "/home_local/<env:USER>/blender/",
    "pip": [
      "h5py",
      "scikit-image"
    ]
  },
  "modules": [
    {
      "module": "main.Initializer",
      "config": {
        "global": {
          "output_dir": "./testing_multi/output"
        }
      }
    },
    {
      "module": "loader.BlendLoader",
      "config": {
        "path": "./testing_multi/scene.blend",
        "load_from": "/Object"  # load all objects from the scene file
      }
    },
    {
      "module": "manipulators.WorldManipulator",
      "config": {
        "cf_set_world_category_id": 0  # this sets the worlds background category id to 0
      }
    },
    {
      "module": "lighting.LightLoader",
      "config": {
        "lights": [
          {
            "type": "POINT",
            "location": [5, -5, 5],
            "energy": 1000
          }
        ]
      }
    },
    {
      "module": "camera.CameraSampler",
      "config": {
        "cam_poses": [
          {
            "number_of_samples": 2,
            "location": {
              "provider":"sampler.Uniform3d",
              "max":[10, 10, 8],
              "min":[-10, -10, 12]
            },
            "rotation": {
              "format": "look_at",
              "value": {
                "provider": "getter.POI"
              },          
              "inplane_rot": {
                "provider": "sampler.Value",
                "type": "float",
                "min": -0.7854,
                "max": 0.7854
              }
            }
          }
        ]
      }
    },
    {
      "module": "renderer.RgbRenderer",
      "config": {
        "output_key": "colors"
      }
    },
    {
      "module": "renderer.SegMapRenderer",
      "config": {
        "map_by": ["instance","class"],
      }
    },
    {
      "module": "writer.CocoAnnotationsWriter",
      "config": {
        "append_to_existing_output": True,
      }
    }
  ]
}

Running multiple times should raise the error previously mentioned and replicated below. You might need to delete the dataset and reattempt a few times to get the problem to occur.

"The existing coco annotations file contains different categories/objects than the current scene. Merging the two lists is not implemented yet."

Which occurs raised at line 102 of src/utility/CocoUtility.py

[MartinSmeyer]

Thanks, the fix will be merged and probably released today in 1.5.1.

[MartinSmeyer]

It should be fixed now