refine image converter

src/Infrastructure/BotSharp.Core/Files/Services/Instruct/FileInstructService.Image.cs

@@ -49,12 +49,13 @@ public partial class FileInstructService
         var innerAgentId = options?.AgentId ?? Guid.Empty.ToString();
         var instruction = await GetAgentTemplate(innerAgentId, options?.TemplateName);
 
-        var completion = CompletionProvider.GetImageCompletion(_services, provider: options?.Provider ?? "openai", model: options?.Model ?? "dall-e-3");
+        var textContent = text.IfNullOrEmptyAs(instruction).IfNullOrEmptyAs(string.Empty);
+        var completion = CompletionProvider.GetImageCompletion(_services, provider: options?.Provider ?? "openai", model: options?.Model ?? "gpt-image-1");
         var message = await completion.GetImageGeneration(new Agent()
         {
             Id = innerAgentId,
             Instruction = instruction
-        }, new RoleDialogModel(AgentRole.User, instruction ?? text));
+        }, new RoleDialogModel(AgentRole.User, textContent));
 
         await HookEmitter.Emit<IInstructHook>(_services, async hook =>
             await hook.OnResponseGenerated(new InstructResponseModel
@@ -123,16 +124,18 @@ public partial class FileInstructService
         if (converter != null)
         {
             binary = await converter.ConvertImageToRgbaPng(binary);
+            image.FileExtension = "png";
         }
 
         using var stream = binary.ToStream();
         stream.Position = 0;
 
-        var fileName = BuildFileName(image.FileName, image.FileExtension, "image", "png");
+        var fileName = BuildFileName(image.FileName,image.FileExtension, "image", "png");
+        var textContent = text.IfNullOrEmptyAs(instruction).IfNullOrEmptyAs(string.Empty);
         var message = await completion.GetImageEdits(new Agent()
         {
             Id = innerAgentId
-        }, new RoleDialogModel(AgentRole.User, instruction ?? text), stream, fileName);
+        }, new RoleDialogModel(AgentRole.User, textContent), stream, fileName);
 
         stream.Close();
 
@@ -174,10 +177,11 @@ public partial class FileInstructService
 
         var imageName = BuildFileName(image.FileName, image.FileExtension, "image", "png");
         var maskName = BuildFileName(image.FileName, image.FileExtension, "mask", "png");
+        var textContent = text.IfNullOrEmptyAs(instruction).IfNullOrEmptyAs(string.Empty);
         var message = await completion.GetImageEdits(new Agent()
         {
             Id = innerAgentId
-        }, new RoleDialogModel(AgentRole.User, instruction ?? text), imageStream, imageName, maskStream, maskName);
+        }, new RoleDialogModel(AgentRole.User, textContent), imageStream, imageName, maskStream, maskName);
 
         imageStream.Close();
         maskStream.Close();

src/Infrastructure/BotSharp.Core/data/agents/01e2fc5c-2c89-4ec7-8470-7688608b496c/agent.json

@@ -4,46 +4,14 @@
   "description": "Chatbot is used to test the performance of different large models and does not interact with external APIs.",
   "type": "task",
   "createdDateTime": "2024-01-15T10:39:32Z",
-  "updatedDateTime": "2025-09-11T20:25:59.292826Z",
+  "updatedDateTime": "2024-01-15T14:39:32Z",
+  "iconUrl": "/images/logo.png",
+  "disabled": false,
+  "isPublic": true,
   "llmConfig": {
     "is_inherit": false,
     "provider": "openai",
-    "model": "gpt-5",
+    "model": "gpt-4o-mini",
     "max_recursion_depth": 3
-  },
+  }
-  "isPublic": true,
-  "disabled": false,
-  "iconUrl": "/images/logo.png",
-  "profiles": [],
-  "labels": [],
-  "mergeUtility": false,
-  "utilities": [
-    {
-      "category": "file",
-      "name": "image-generator",
-      "disabled": false,
-      "items": [
-        {
-          "function_name": "util-file-generate_image",
-          "template_name": "util-file-generate_image.fn"
-        }
-      ]
-    },
-    {
-      "category": "file",
-      "name": "image-editor",
-      "disabled": false,
-      "items": [
-        {
-          "function_name": "util-file-edit_image",
-          "template_name": "util-file-edit_image.fn"
-        }
-      ]
-    }
-  ],
-  "mcpTools": [],
-  "rules": [],
-  "knowledgeBases": [],
-  "inheritAgentId": null,
-  "routingRules": []
 }

src/Infrastructure/BotSharp.OpenAPI/ViewModels/Instructs/Request/InstructBaseRequest.cs

@@ -51,7 +51,7 @@ public class ImageEditRequest : InstructBaseRequest
     public string Text { get; set; } = string.Empty;
 
     [JsonPropertyName("image_converter_provider")]
-    public string? ImageConverterProvider { get; set; } = "file-handler";
+    public string? ImageConverterProvider { get; set; }
 }
 
 public class ImageEditFileRequest : ImageEditRequest

src/Plugins/BotSharp.Plugin.FileHandler/Converters/FileHandlerImageConverter.cs

@@ -1,5 +1,6 @@
 using SixLabors.ImageSharp;
 using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Formats.Png;
 using System.IO;
 
 namespace BotSharp.Plugin.FileHandler.Converters;
@@ -25,7 +26,11 @@ public class FileHandlerImageConverter : IImageConverter
         {
             using var image = Image.Load<Rgba32>(binary.ToArray());
             using var memoryStream = new MemoryStream();
-            image.SaveAsPng(memoryStream);
+
+            image.SaveAsPng(memoryStream, new PngEncoder
+            {
+                ColorType = PngColorType.RgbWithAlpha
+            });
             var convertedBinary = BinaryData.FromBytes(memoryStream.ToArray());
             return await Task.FromResult(convertedBinary);
         }

src/Plugins/BotSharp.Plugin.FileHandler/Functions/EditImageFn.cs

@@ -84,6 +84,7 @@ public class EditImageFn : IFunctionCallback
             var fileStorage = _services.GetRequiredService<IFileStorageService>();
             var fileBinary = fileStorage.GetFileBytes(image.FileStorageUrl);
             var rgbaBinary = await ConvertImageToRgbaWithPng(fileBinary);
+            image.FileExtension = "png";
 
             using var stream = rgbaBinary.ToStream();
             stream.Position = 0;
@@ -148,7 +149,7 @@ public class EditImageFn : IFunctionCallback
 
     private async Task<BinaryData> ConvertImageToRgbaWithPng(BinaryData binaryFile)
     {
-        var provider = _settings?.ImageConverter?.Provider ?? "file-handler";
+        var provider = _settings?.ImageConverter?.Provider;
         var converter = _services.GetServices<IImageConverter>().FirstOrDefault(x => x.Provider == provider);
         if (converter == null)
         {

src/WebStarter/appsettings.json

@@ -449,11 +449,11 @@
       },
       "Generation": {
         "LlmProvider": "openai",
-        "LlmModel": "dall-e-3"
+        "LlmModel": "gpt-image-1"
       },
       "Edit": {
         "LlmProvider": "openai",
-        "LlmModel": "dall-e-2"
+        "LlmModel": "gpt-image-1"
       },
       "Variation": {
         "LlmProvider": "",
@@ -469,7 +469,7 @@
       }
     },
     "ImageConverter": {
-      "Provider": "file-handler"
+      "Provider": null
     }
   },