LayerGroup.AddLayer

public void AddLayer(Layer layer)

[C#]

string outputFilePath = "PsdResult.psd";

var filesList = new string[]
{
    "PsdExample.psd",
    "BmpExample.bmp",
    "GifExample.gif",
    "Jpeg2000Example.jpf",
    "JpegExample.jpg",
    "PngExample.png",
    "TiffExample.tif",
};

using (var image = new PsdImage(200, 200))
{
    foreach (var fileName in filesList)
    {
        string filePath = fileName;
        using (var stream = new FileStream(filePath, FileMode.Open))
        {
            Layer layer = null;
            try
            {
                layer = new Layer(stream);
                image.AddLayer(layer);
            }
            catch (Exception e)
            {
                if (layer != null)
                {
                    layer.Dispose();
                }

                throw e;
            }
        }
    }

    image.Save(outputFilePath);
}