Convert XLS (Excel) to PPM

The XLS file extension, short for "Excel Spreadsheet", is a legacy format used by Microsoft Excel for storing spreadsheet data. Introduced with Excel 2.0 in 1987, it was the primary format until the introduction of XLSX in 2007. XLS files contain data organized in rows and columns, supporting formulas, macros, and various formatting options, making them essential for data analysis and financial reporting. Despite being replaced by the more robust and secure XLSX format, XLS files remain widely used in many legacy systems and applications.

The Portable Pixmap (PPM) file extension, an image format within the Netpbm family, stores simple, uncompressed images. Introduced in the late 1980s, PPM supports RGB color and grayscale images, making it suitable for basic image processing and conversion tasks. Its plain text encoding simplifies debugging and data manipulation, although its lack of compression results in larger file sizes compared to modern formats. As such, PPM finds limited use in contemporary applications, mainly in educational and experimental settings where ease of implementation and readability are prioritized.