Word JavaScript API missing API to restore pictures to its original size.

In Word .Net API, I can restore picturesto its original size with the following code

foreach (Word.InlineShape shape in document.InlineShapes)
{
    if (shape.Type == Word.WdInlineShapeType.wdInlineShapePicture)
    {
        Debug.WriteLine("found a picture");
        Office.MsoTriState preLockAspectRatio = shape.LockAspectRatio;
        shape.LockAspectRatio = Office.MsoTriState.msoFalse;
        shape.ScaleWidth = 100.0F;
        shape.ScaleHeight = 100.0F;
        shape.LockAspectRatio = preLockAspectRatio;
        Debug.WriteLine("restore a picture size");
    }

}

But in Word JavaScript API, I couldn't found any API to implement that. It only support to access current size of picture.