Image Processing MCP Server

Instructions

Implementation Reference

• main.py:122-137 (registration)

  Registers the 'save_image' MCP tool using @mcp.tool() decorator. Defines input schema via Annotated parameters with Field descriptions. Delegates execution to basic_save_image from tools.basic.
  def save_image( image_source: Annotated[str, Field(description="图片源，可以是文件路径或base64编码的图片数据")], output_path: Annotated[str, Field(description="输出文件路径，包含文件名和扩展名（如 'output.png'）")], format: Annotated[str, Field(description="图片格式，支持 PNG、JPEG、WEBP、BMP、TIFF 等", default="PNG")], quality: Annotated[int, Field(description="图片质量，范围 1-100，仅对 JPEG 格式有效", ge=1, le=100, default=95)] ) -> str: """保存图片到指定路径""" try: result = safe_run_async(basic_save_image(image_source, output_path, format, quality)) return result[0].text except Exception as e: return json.dumps({ "success": False, "error": f"保存图片失败: {str(e)}" }, ensure_ascii=False, indent=2)
• tools/basic.py:154-212 (handler)

  Core handler function for save_image tool. Validates parameters, loads image from base64 data using ImageProcessor, saves the image to output_path, computes file size, and returns JSON result.
  async def save_image(image_data: str, output_path: str, format: str = "PNG", quality: int = 95) -> list[TextContent]: """ 保存图片到指定路径 Args: image_data: 图片数据（base64编码） output_path: 输出文件路径 format: 图片格式 quality: 图片质量 Returns: 保存结果响应 """ try: # 验证参数 if not image_data or not output_path: raise ValidationError("图片数据和输出路径不能为空") if not validate_image_format(format): raise ValidationError(f"不支持的图片格式: {format}") if not (1 <= quality <= 100): raise ValidationError("图片质量必须在1-100之间") # 加载图片 image = processor.load_image(image_data) # 保存图片 saved_path = processor.save_image(image, output_path, format, quality) # 获取文件信息 file_size = os.path.getsize(saved_path) result = { "success": True, "message": "图片保存成功", "data": { "output_path": saved_path, "format": format, "file_size": file_size, "quality": quality } } return [TextContent(type="text", text=json.dumps(result, ensure_ascii=False))] except ValidationError as e: error_result = { "success": False, "error": f"参数验证失败: {str(e)}" } return [TextContent(type="text", text=json.dumps(error_result, ensure_ascii=False))] except Exception as e: error_result = { "success": False, "error": f"图片保存失败: {str(e)}" } return [TextContent(type="text", text=json.dumps(error_result, ensure_ascii=False))]
• utils/image_processor.py:65-97 (helper)

  Low-level helper method in ImageProcessor class that performs the actual PIL Image saving to disk, handling JPEG transparency conversion and directory creation.
  def save_image(self, image: Image.Image, output_path: str, format: str = 'PNG', quality: int = 95) -> str: """ 保存图片到指定路径 Args: image: PIL Image对象 output_path: 输出文件路径 format: 图片格式 quality: 图片质量 (1-100) Returns: 保存的文件路径 """ try: # 确保输出目录存在 os.makedirs(os.path.dirname(output_path), exist_ok=True) # 保存图片 if format.upper() == 'JPEG': # JPEG不支持透明度，需要转换 if image.mode in ('RGBA', 'LA'): background = Image.new('RGB', image.size, (255, 255, 255)) background.paste(image, mask=image.split()[-1] if image.mode == 'RGBA' else None) image = background image.save(output_path, format=format, quality=quality) else: image.save(output_path, format=format) return output_path except Exception as e: raise IOError(f"图片保存失败: {str(e)}")
• tools/basic.py:26-54 (schema)

  Input schema definition for save_image tool in the get_basic_tools() function (potentially unused as main.py uses Annotated schema).
  Tool( name="save_image", description="保存图片到指定路径", inputSchema={ "type": "object", "properties": { "image_data": { "type": "string", "description": "图片数据（base64编码）" }, "output_path": { "type": "string", "description": "输出文件路径" }, "format": { "type": "string", "description": "图片格式（PNG, JPEG, BMP等）", "default": "PNG" }, "quality": { "type": "integer", "description": "图片质量（1-100，仅对JPEG有效）", "minimum": 1, "maximum": 100, "default": 95 } }, "required": ["image_data", "output_path"] }