Kdu_channel_mapping channels = new Kdu_channel_mapping();
if (inputSource.Exists())
channels.Configure(inputSource, false);
else
channels.Configure(codestream);
int ref_component = channels.Get_source_component(0);
Kdu_coords ref_expansion = getReferenceExpansion(ref_component, channels, codestream);
Kdu_dims image_dims = new Kdu_dims();
codestream.Get_dims(ref_component, image_dims);
Kdu_coords imageSize = image_dims.Access_size();