Use the Aspose.Cells Cloud REST API to add a background image to an Excel workbook. The API is available through cURL or any of the supported SDKs (C#, Java, Python, Ruby, Go, etc.)....Use the Aspose.Cells Cloud REST API to add a background image to an Excel workbook. The API is available through cURL or any of the supported SDKs (C#, Java, Python, Ruby, Go, etc.).