Object reference not set to an instance of an object error in Focus Model

[saymongriffin]

Hi. In Focus Model i have an error like this. Can you help me to solve this?

   
System.NullReferenceException
      HResult=0x80004003
      Message=Object reference not set to an instance of an object.
      Source=Clarifai
      StackTrace:
       at Clarifai.DTOs.Models.Outputs.ClarifaiOutput.DeserializePredictions(String typeName, Object jsonObject)
       at Clarifai.DTOs.Models.Outputs.ClarifaiOutput`1.Deserialize(Object jsonObject)
       at Clarifai.API.Requests.Models.PredictRequest`1.Unmarshaller(Object jsonObject)
       at Clarifai.API.Requests.ClarifaiRequest`1.<ExecuteAsync>d__8.MoveNext()
       at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
       at WindowsFormsApp1.Form1.<button16_Click>d__26.MoveNext() in d:\Users\ivan\source\repos\WindowsFormsApp1\WindowsFormsApp1\Form1.cs:line 833

Here source code of operation where error located.

 if (Images_Compare_Grid[0, n].Value.ToString() != null)
                    {
                        var resor = await client.PublicModels.FocusModel.Predict(new ClarifaiURLImage(Images_Compare_Grid[0, n].Value.ToString())).ExecuteAsync();
                        if (resor != null)
                        {
                            foreach (var concept in resor.Get().Data)
                            {

                            Screen_Analyze_Grid.Rows.Add($"Focus Value", $"{concept.Value}", links, vid_id);
                            string sql = "INSERT INTO an_base_our_screens (name,value,img_link,vid_id) VALUES (@name,@val,@link,@img_id)";
                            using (MySqlCommand cmd1 = new MySqlCommand(sql, conn))
                            {
                                cmd1.Parameters.AddWithValue("@name", "Focus Value");
                                cmd1.Parameters.AddWithValue("@val", concept.Value);
                                cmd1.Parameters.AddWithValue("@link", links);
                                cmd1.Parameters.AddWithValue("@img_id", vid_id);

                                cmd1.ExecuteNonQuery();
                            }
                        }
                    }
                }

[jared]

Hi @saymongriffin! The problem here is that this particular code is tailored towards our Concept Models (e.g. General, NSFW, Food, Apparel, etc.) which simply return concepts and their corresponding probabilities. Those have a JSON return structure of:

"data": {
        "concepts": [
          {
            "id": "ai_HLmqFqBf",
            "name": "train",
            "app_id": null,
            "value": 0.9989112
          },
          {
            "id": "ai_fvlBqXZR",
            "name": "railway",
            "app_id": null,
            "value": 0.9975532
          },
          {
            "id": "ai_Xxjc3MhT",
            "name": "transportation system",
            "app_id": null,
            "value": 0.9959158
          },
          {
            "id": "ai_6kTjGfF6",
            "name": "station",
            "app_id": null,
            "value": 0.992573
          },

...etc...

The Focus Model however, returns all the regions in focus (via bounding box coordinates), the focus score of that region and an overall focus score, so it's structure is a bit different:

 "data": {
    "focus": {
      "value": 0.96578157
    },
    "regions": [
      {
        "region_info": {
          "bounding_box": {
            "top_row": 0.328125,
            "left_col": 0.28125,
            "bottom_row": 0.84375,
            "right_col": 0.71875
          }
        },
        "data": {
          "focus": {
            "density": 0.72727275
          }
        }
      }
    ]

In the example above, the picture has only one focus region, but there could potentially be many.

Let me know if you need further help with this!

[saymongriffin]

Thx @jared
So there a problem with getting result, as you see. I need only Focus Value and in my code i return only this value.
How i can solve this problem?

General model working correctly with same code.

[saymongriffin]

When i getting only 1 pic (i check every pic), all is ok. I was thinking the function returns 0, because it don't found any focus region on pic, but this wrong, cause every my pic have it. So problem, is still unsolved

[jared]

Hi @saymongriffin - if you're just looking for the overall focus value you can access it with:

resor.Get().Data.focus.value

You won't need to loop through anything to get that since it's at the top before the regions are outputted.

[saymongriffin]

Thx Jared. I solve this problem.
When i have this error, response is null (pic don't have any focus area -> Focus Value). I just catch exception and go to next iteration of cycle.