When image watermark is set and its height is configured through DocumentWatermarkSettings.ImageSettings.Size.Height, the height is not respected.

Steps to reproduce:
1. Insert a Watermark with size
           var watermarkSettings = new DocumentWatermarkSettings()
            {
                Type = WatermarkType.ImageWatermark,
                ImageSettings = new WatermarkImageSettings()
                {
                    UriSource = new Uri("c:\1.jpg"),
                    Size = new Size(200, 300)
                }
            };

Expected: The image is with the specified width and height.
Actual: The height is different.