I'm trying to join split render files. That is, I have horizontal strips of a complete image, where each strip is a multi-layered PSD (16bit RGB). All strip files have the same layers, layer order, etc. Some have masks.
So far, following the -append documentation, I get several JPG files if I output to JPG, an unreadable PSD file if I output a PSD, or a single layer (using the active layer from the PSD) tif.
How do I non destructively merge these files, with the end result being the same as the input (16bit RGB multi-layer PSD)?