ICS file converter
The Huygens Software can read and writeICS and ICS2 files, and export them to other image File Formats (and vice versa), even in FreeWare mode. You can download the Huygens Suite and use any of its components (like the Huygens Essential) for that purpose. The Huygens Scripting (also found in that suite) is a programmable environment that you can use to convert files in your automated scripts, and since Huygens version 20.10 you can not only perform batch image processing but also batch conversion of file formats with the Workflow Processor.