Class PathResourceConverter

public static class PathResourceConverter
   {
      public static string Convert(string resourcePath)
      {
         if (string.IsNullOrEmpty(resourcePath))
            return null;
         var pathParts = resourcePath.Split('.');
         var extension = pathParts[pathParts.Length - 1];
         var resourceName = string.Join(".", pathParts.Take(pathParts.Length - 1).ToArray());
         if (extension == "resx")
         {
            return ConvertResxResource(resourcePath);
         }
         else if (extension == "xaml")
         {
            return ConvertXamlResource(resourcePath);
         }
         return null;
      }
      private static string ConvertResxResource(string resourcePath)
      {
      }
      private static string ConvertXamlResource(string resourcePath)
      {
      }
   }

using (var image as TiffImage = Image.Load("Bottle.tif"))
   {
       var graphicsPath = PathResourceConverter.ToGraphicsPath(image.ActiveFrame.PathResources.ToArray(), image.ActiveFrame.Size);
       var graphics = new Graphics(image);
       graphics.DrawPath(new Pen(Color.Red, 10), graphicsPath);
       image.Save("BottleWithRedBorder.tif");
   }

static void Main(string[] args)
   {
       using (var image = (TiffImage)Image.Load("Bottle.tif"))
       {
           var figure = new Figure();
           figure.AddShape(CreateBezierShape(100f, 100f, 500f, 100f, 500f, 1000f, 100f, 1000f));
           var graphicsPath = new GraphicsPath();
           graphicsPath.AddFigure(figure);
           var pathResouze = PathResourceConverter.FromGraphicsPath(graphicsPath, image.Size);
           image.ActiveFrame.PathResources = new List<PathResource>(pathResouze);
           image.Save("BottleWithRectanglePath.tif");
       }
       private static BezierShape CreateBezierShape(params float[] coordinates)
       {
           var bezierPoints = CoordinatesToBezierPoints(coordinates).ToArray();
           return new BezierShape(bezierPoints, true);
       }
       private static IEnumerable<PointF> CoordinatesToBezierPoints(float[] coordinates)
       {
           for (var coordinateIndex = 0; coordinateIndex < coordinates.Length; coordinateIndex += 2)
               for (var index = 0; index < 3; index++)
                   yield return new PointF(coordinates[coordinateIndex], coordinates[coordinateIndex + 1]);
       }

public static PathResource[] FromGraphicsPath(GraphicsPath graphicsPath, Size imageSize)
{
}
Here's the reformatted version of your code:
public static PathResource[] FromGraphicsPath(GraphicsPath graphicsPath, Size imageSize)
{
}
As you can see, I have maintained proper indentation, spacing, and general readability improvements as per the given instructions.

public static GraphicsPath ToGraphicsPath(
    PathResource[] pathResources,
    Size imageSize)
{
    GraphicsPath graphicsPath = new GraphicsPath();
    foreach (var pathResource in pathResources)
    {
    }
    return graphicsPath;
}