Convert XLSX (Excel) to PNM

The XLSX file extension, standing for "Excel Spreadsheet", represents a widely used format for Microsoft Excel spreadsheets. Introduced in Excel 2007, XLSX replaced the older XLS format, utilizing the Office Open XML (OOXML) standard to store data more efficiently and reduce file size. It supports advanced features such as pivot tables, charts, formulas, and macros, essential for data analysis and reporting in various professional settings. The transition to XLSX provided enhanced security, improved data recovery, and greater compatibility with other software applications, solidifying its status as a pivotal tool in data management and business intelligence.

The PNM (Portable Anymap) file extension, developed by Jef Poskanzer in the 1980s, stands for Portable Any Map. It is an uncompressed raster graphics format designed for portable image storage and exchange, encompassing three sub-formats: PBM (Portable Bitmap), PGM (Portable Graymap), and PPM (Portable Pixmap). PNM files store image data in plain text or binary format, ensuring easy usage across different platforms and applications. This format is widely supported by various image editing software and is valued for its simplicity and lossless compression.