public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
var jsonArray = JArray.Load(reader);
var firstDim = jsonArray.Count;
var secondArray = jsonArray[0] as JArray;
var secondDim = secondArray?.Count;
var thirdArray = secondArray?[0] as JArray;
var thirdDim = thirdArray?.Count;
var fourArray = thirdArray?[0] as JArray;
var fourDim = fourArray?.Count;
if (secondDim == null || thirdDim == null || fourDim == null)
{
return(null);
}
var netArray = new NoLohArray4D <float>(firstDim, secondDim.Value, thirdDim.Value, fourDim.Value);
for (int x = 0; x < firstDim; x++)
{
secondArray = jsonArray[x] as JArray;
if (secondArray == null)
{
throw new Exception("The json is malformed");
}
for (int y = 0; y < secondDim; y++)
{
thirdArray = secondArray[y] as JArray;
if (thirdArray == null)
{
throw new Exception("The json is malformed");
}
for (int z = 0; z < thirdDim; z++)
{
fourArray = thirdArray[z] as JArray;
if (fourArray == null)
{
throw new Exception("The json is malformed");
}
for (int w = 0; w < fourDim; w++)
{
netArray[x, y, z, w] = fourArray[w].Value <float>();
}
}
}
}
return(netArray);
}
public void ReturnBoundingBoxes_WhenAHeatmapProbabilityIsSupplied()
{
const float threshold = 0.7f;
const float scale = 0.5f;
using (var probabilities = new NoLohArray3D <float>(50, 50, 2))
using (var heatmap = new NoLohArray4D <float>(1, 50, 50, 4))
{
probabilities[2, 4, 1] = 0.8f;
probabilities[4, 8, 1] = 0.9f;
var boxes = Box.CreateFromMtcnnHeatMap(probabilities, heatmap, scale, threshold);
boxes.Should().NotBeEmpty();
boxes.Should().HaveCount(2);
boxes.Should().Contain(item =>
item.MinX == 8 && item.MaxX == 32 && item.MinY == 16 && item.MaxY == 40 && Math.Abs(item.Score - 0.8f) < Bootstrapper.FloatTolerance);
boxes.Should().Contain(item =>
item.MinX == 16 && item.MaxX == 40 && item.MinY == 32 && item.MaxY == 56 && Math.Abs(item.Score - 0.9f) < Bootstrapper.FloatTolerance);
}
}
public static IEnumerable <Box> CreateFromMtcnnHeatMap(NoLohArray3D <float> probabilities, NoLohArray4D <float> heatmap, float scale, float threshold)
{
const float stride = 2f;
const float cellSize = 12f;
const int zIndex = 1;
var positions = new ConcurrentBag <(int X, int Y, float Score)>();
Parallel.For(0, probabilities.XLength, x =>
{
for (int y = 0; y < probabilities.YLength; y++)
{
if (probabilities[x, y, zIndex] > threshold)
{
positions.Add((x, y, probabilities[x, y, zIndex]));
}
