Image Processing MCP Server

Instructions

Implementation Reference

• tools/effects.py:417-515 (handler)

  Core implementation of the create_silhouette tool. Processes the input image by thresholding alpha channel pixels and filling with silhouette color, handles background, and outputs base64 image.
  async def create_silhouette(arguments: Dict[str, Any]) -> List[TextContent]: """ 创建图片的剪影效果 Args: arguments: 包含图片源和剪影参数的字典 Returns: List[TextContent]: 处理结果 """ try: # 参数验证 image_source = arguments.get("image_source") ensure_valid_image_source(image_source) silhouette_color = arguments.get("silhouette_color", "#000000") background_color = arguments.get("background_color", "transparent") threshold = arguments.get("threshold", 128) output_format = arguments.get("output_format", DEFAULT_IMAGE_FORMAT) # 验证参数 validate_color_hex(silhouette_color) if background_color != "transparent": validate_color_hex(background_color) validate_numeric_range(threshold, 0, 255, "threshold") # 加载图片 processor = ImageProcessor() image = processor.load_image(image_source) # 转换为RGBA模式 if image.mode != "RGBA": image = image.convert("RGBA") # 创建剪影 silhouette = Image.new("RGBA", image.size, (0, 0, 0, 0)) # 获取像素数据 pixels = image.load() silhouette_pixels = silhouette.load() # 解析剪影颜色 silhouette_rgb = tuple(int(silhouette_color[i:i+2], 16) for i in (1, 3, 5)) for y in range(image.height): for x in range(image.width): r, g, b, a = pixels[x, y] # 如果像素不透明度大于阈值，则设为剪影颜色 if a > threshold: silhouette_pixels[x, y] = silhouette_rgb + (255,) else: silhouette_pixels[x, y] = (0, 0, 0, 0) # 处理背景 if background_color != "transparent": background_rgb = tuple(int(background_color[i:i+2], 16) for i in (1, 3, 5)) final_image = Image.new("RGB", image.size, background_rgb) final_image.paste(silhouette, (0, 0), silhouette) else: final_image = silhouette # 转换为base64 output_info = processor.output_image(final_image, "silhouette", output_format) return [TextContent( type="text", text=json.dumps({ "success": True, "message": "成功创建剪影效果", "data": { **output_info, "metadata": { "size": f"{image.width}x{image.height}", "silhouette_color": silhouette_color, "background_color": background_color, "threshold": threshold, "format": output_format } } }, ensure_ascii=False) )] except ValidationError as e: return [TextContent( type="text", text=json.dumps({ "success": False, "error": f"参数验证失败: {str(e)}" }, ensure_ascii=False) )] except Exception as e: return [TextContent( type="text", text=json.dumps({ "success": False, "error": f"创建剪影失败: {str(e)}" }, ensure_ascii=False) )]
• main.py:517-541 (registration)

  MCP tool registration for create_silhouette using FastMCP's @mcp.tool() decorator. Defines the input schema with pydantic validations and delegates execution to the handler in tools/effects.py.
  @mcp.tool() def create_silhouette( 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")], silhouette_color: Annotated[str, Field(description="剪影颜色，十六进制格式如 #000000（黑色）", default="#000000")], background_color: Annotated[str, Field(description="背景颜色，十六进制格式或 'transparent'（透明）", default="transparent")], threshold: Annotated[int, Field(description="阈值，范围 0-255，用于确定剪影边界", ge=0, le=255, default=128)], output_format: Annotated[str, Field(description="输出格式：PNG、JPEG、WEBP 等", default="PNG")] ) -> str: """创建图片的剪影效果""" try: arguments = { "image_source": image_source, "silhouette_color": silhouette_color, "background_color": background_color, "threshold": threshold, "output_format": output_format } result = safe_run_async(effects_create_silhouette(arguments)) return result[0].text except Exception as e: return json.dumps({ "success": False, "error": f"创建剪影失败: {str(e)}" }, ensure_ascii=False, indent=2)
• tools/effects.py:77-112 (schema)

  JSON schema definition for create_silhouette tool inputs, defined in get_effect_tools() function (though registration uses pydantic fields in main.py).
  Tool( name="create_silhouette", description="创建图片的剪影效果", inputSchema={ "type": "object", "properties": { "image_source": { "type": "string", "description": "图片源（文件路径或base64编码）" }, "silhouette_color": { "type": "string", "description": "剪影颜色（十六进制格式）", "default": "#000000" }, "background_color": { "type": "string", "description": "背景颜色（十六进制格式，transparent表示透明）", "default": "transparent" }, "threshold": { "type": "integer", "description": "透明度阈值（0-255）", "minimum": 0, "maximum": 255, "default": 128 }, "output_format": { "type": "string", "description": "输出格式", "enum": ["PNG", "JPEG", "WEBP"], "default": "PNG" } }, "required": ["image_source"] }