/// Add an image to the payload from a pixel buffer.
/// The pixel buffer MUST have an RGBA8888 pixel layout.
/// <param name="pixelBuffer">Pixel buffer containing image to add.</param>
/// <param name="width">Image width.</param>
/// <param name="height">Image height.</param>
void AddImage<T> (T[] pixelBuffer, int width, int height) where T : struct;
/// Add an image to the payload.
/// Note that the image MUST be readable.
/// <param name="image">Image to add.</param>
void AddImage (Texture2D image);