diff --git a/src/TrackMate.Backend.RestApi/Hubs/TrackNodeHub.cs b/src/TrackMate.Backend.RestApi/Hubs/TrackNodeHub.cs
index 57b4f34..6d255de 100644
--- a/src/TrackMate.Backend.RestApi/Hubs/TrackNodeHub.cs
+++ b/src/TrackMate.Backend.RestApi/Hubs/TrackNodeHub.cs
@@ -2,6 +2,7 @@
 using System.Collections.Concurrent;
 using Trackmate.Backend;
 using Trackmate.Backend.Models;
+using Trackmate.Backend.TrackNodes;
 
 namespace TrackMate.Backend.RestApi.Hubs;
 
@@ -32,23 +33,9 @@ public async Task<TrackNodeModel> CreateTrackNode(CreateTrackNodeModel model)
     /// <param name="mimeType">Mime/Type of the uploaded image.</param>
     /// <param name="chunk">Byte chunk of the image uploaded.</param>
     /// <param name="isLastChunk">Flag if the upload is completed.</param>
-    public async Task UploadPictureChunkForTrackNode(Guid trackNodeId, string mimeType, byte[] chunk, bool isLastChunk)
+    public async Task UploadPictureChunkForTrackNode(UploadPictureModel uploadPictureModel)
     {
-        logger.LogInformation("Uploaded chunk({byteSize}) for new track node {trackNodeId}.", chunk.Length, trackNodeId);
-        await _trackNodeUploadDictionary[trackNodeId].WriteAsync(chunk);
-
-        if (isLastChunk)
-        {
-            logger.LogInformation("Uploaded last chunk for track node {trackNodeId}, MimeType: {mimeType}.", trackNodeId, mimeType);
-            await Clients.Caller.SendAsync("Uploaded ", trackNodeId);
-
-            Stream stream = _trackNodeUploadDictionary[trackNodeId];
-            _trackNodeUploadDictionary.Remove(trackNodeId);
-            stream.Seek(0, SeekOrigin.Begin);
-
-            await trackNodeService.UploadTrackNodePictureAsync(new UploadPictureModel(trackNodeId, mimeType, stream), default);
-            logger.LogInformation("Uploaded picture for track node {trackNodeId}.", trackNodeId);
-        }
+        await trackNodeService.UploadTrackNodePictureAsync(uploadPictureModel, default);
     }
 
     /// <summary>
diff --git a/src/Trackmate.Backend/Models/UploadPictureModel.cs b/src/Trackmate.Backend/Models/UploadPictureModel.cs
deleted file mode 100644
index faf2565..0000000
--- a/src/Trackmate.Backend/Models/UploadPictureModel.cs
+++ /dev/null
@@ -1,3 +0,0 @@
-namespace Trackmate.Backend.Models;
-
-public record UploadPictureModel(Guid TrackNodeId, string MimeType, Stream imageData);
diff --git a/src/Trackmate.Backend/TrackNodeService.cs b/src/Trackmate.Backend/TrackNodeService.cs
index 87adca6..960a2cf 100644
--- a/src/Trackmate.Backend/TrackNodeService.cs
+++ b/src/Trackmate.Backend/TrackNodeService.cs
@@ -19,7 +19,9 @@ public async Task<TrackNodeModel> CreateTrackNodeAsync(CreateTrackNodeModel mode
     public async Task<TrackNodeModel> UploadTrackNodePictureAsync(UploadPictureModel uploadPictureModel, CancellationToken cancellationToken)
     {
         logger.LogInformation("Enriching track node (id:{trackNodeId} with picture embedding.", uploadPictureModel.TrackNodeId);
-        PictureEmbeddingModel embedding = await embeddingClient.GeneratePictureEmbeddingAsync(uploadPictureModel.MimeType, uploadPictureModel.imageData);
+
+        using Stream dataStream = new MemoryStream(Convert.FromBase64String(uploadPictureModel.ImageDataBase64));
+        PictureEmbeddingModel embedding = await embeddingClient.GeneratePictureEmbeddingAsync(uploadPictureModel.MimeType, dataStream);
         return await trackNodeDataSource.AppendEmbeddingAsync(uploadPictureModel.TrackNodeId, embedding, cancellationToken);
     }
 }
\ No newline at end of file
diff --git a/src/Trackmate.Backend/TrackNodes/UploadPictureModel.cs b/src/Trackmate.Backend/TrackNodes/UploadPictureModel.cs
new file mode 100644
index 0000000..9682faf
--- /dev/null
+++ b/src/Trackmate.Backend/TrackNodes/UploadPictureModel.cs
@@ -0,0 +1,3 @@
+namespace Trackmate.Backend.TrackNodes;
+
+public record UploadPictureModel(Guid TrackNodeId, string ImageDataBase64, string MimeType);