#CustomVision – Sort and manage Json response estimation in a single line of code

Buy Me A Coffee

Hi!

On my Custom Vision samples, I usually send an image to a CustomVision.ai HTTP Endpoint, and I process the Json result. The results are very easy to understand, however, I created a C# converter class to help with the Custom Vision results.

To create this class I navigate: http://json2csharp.com/, and paste a sample result and make some changes on the result. The output and useful class is this one:

using System;
using System.Collections.Generic;
using System.Globalization;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
// created with https://app.quicktype.io/#l=cs&r=
namespace DistractedDriverDetectionShared
{
public partial class CustomVisionEstimation
{
[JsonProperty("created")]
public DateTimeOffset Created { get; set; }
[JsonProperty("id")]
public string Id { get; set; }
[JsonProperty("iteration")]
public string Iteration { get; set; }
[JsonProperty("predictions")]
public Prediction[] Predictions { get; set; }
[JsonProperty("project")]
public string Project { get; set; }
}
public partial class Prediction
{
[JsonProperty("boundingBox")]
public object BoundingBox { get; set; }
[JsonProperty("probability")]
public double Probability { get; set; }
[JsonProperty("tagId")]
public string TagId { get; set; }
[JsonProperty("tagName")]
public string TagName { get; set; }
}
public partial class CustomVisionEstimation
{
public static CustomVisionEstimation FromJson(string json) => JsonConvert.DeserializeObject<CustomVisionEstimation>(json, Converter.Settings);
}
public static class Serialize
{
public static string ToJson(this CustomVisionEstimation self) => JsonConvert.SerializeObject(self, Converter.Settings);
}
internal static class Converter
{
public static readonly JsonSerializerSettings Settings = new JsonSerializerSettings
{
MetadataPropertyHandling = MetadataPropertyHandling.Ignore,
DateParseHandling = DateParseHandling.None,
Converters =
{
new IsoDateTimeConverter { DateTimeStyles = DateTimeStyles.AssumeUniversal }
},
};
}
}

It’s a very simple class, and the best way to describe it, is to show an usage scenario

// open file as byte array
var byteData = GetImageAsByteArray(imageFilePath);
// prediction
var client = new HttpClient();
using var content = new ByteArrayContent(byteData);
content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
var response = await client.PostAsync(Url, content);
var jsonResponse = await response.Content.ReadAsStringAsync();
// Display results
var est = CustomVisionEstimation.FromJson(jsonResponse);
var prediction = est.Predictions.OrderByDescending(x => x.Probability).FirstOrDefault();
Console.WriteLine(@$"{prediction.TagName} – {prediction.Probability}");

The main remarks points are

  • Lines 1 to 9, open a local file, create a HTTP client and make the HTTP Post request
  • Line 12, convert the json response (string) to a C# object and then get the best prediction
  • Where the best prediction is a single Linq code sorting the predictions by probability and selecting the 1t one.

Easy and amazing!

Happy Coding!

Greetings @ Burlington

El Bruno

References

2 thoughts on “#CustomVision – Sort and manage Json response estimation in a single line of code

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.