Send complex DTO to web api using jquery ajax

I have a DTO Object like that:

public class ImageDto : EntityDTO
{
    public ImageDto()
    {
        Position = new PositionDTO();
        Rotation = new RotationDTO();
        Size = new SizeDTO();
    }

    public string Name { get; set; }
    public string Source { get; set; }
    public string Description { get; set; }
    public string Style { get; set; }
    public string Link { get; set; }
    public int ZIndex { get; set; }
    public string Effect { get; set; }
    public PositionDTO Position { get; set; }
    public RotationDTO Rotation { get; set; }
    public SizeDTO Size { get; set; }

}

And I have a Web Api with a method like that:

    // POST api/Image/CreateImage
    [HttpPost]
    [Route("CreateImage")]
    public IHttpActionResult CreateImage([FromBody]ImageDto imageDto)
    {
        if (imageDto == null)
            return BadRequest();

        return Ok();

    }

When I try to send my DTO from Jquery Ajax, the values of the complex types (PositionDTO, RotationDTO and SizeDTO are always 0.0)

This is my code using jQuery AJAX:

var urlApi = '/api/Image/CreateImage';

    var imageDTO =
    {
        Name: "",
        Source: "",
        Description: "",
        IdSlide: "9aa2d084-dd82-457b-a80d-9af8375c59ff",
        Style: "",
        Link: "",
        ZIndex: "",
        Effect: "",
        SizeDTO: {
            Width: 200,
            Height: 200,
        },
        PositionDTO: {
            PositionLeft: 200,
            PositionTop: 200,
        },

        RotationDTO: { Rotation: 180 },

        IdGenially: "54006b50b59f86143834c187"

    };

    function getData() {
        return $.ajax({
            url: urlApi,
            type: 'POST',
            data: JSON.stringify(imageDTO),
            contentType: "application/json; charset=utf-8"
        });
    }

How can I do for obtain the value of the DTO Object in JavaScript and not a 0.0 for all complex values? The other values are coming fine.

Regards!!