How to Convert PGM to HDR

Radiance HDR (.hdr), created in 1991, remains in use today by architectural lighting tools and some 3D rendering software, while PGM, from the Netpbm family, stores standard 8-bit grayscale data with no extended dynamic range capability. Converting PGM to HDR doesn't add the extended range that true HDR capture or rendering provides — the conversion simply changes the container format to one specific lighting or rendering software expects.

This is useful only when grayscale research-generated or simulation-derived image data, such as a luminance map, needs to enter a workflow that specifically expects a .hdr file as input.

1. Install Turbo Batch Image Converter Pro on your Windows PC.
2. Open the app and select Batch Mode for multiple files, or Individual Mode for a single PGM.
3. Drag your PGM file or folder into the app window, enabling recursive folder scanning if needed.
4. Set the "From" format to PGM and the "To" format to HDR.
5. Click Convert. HDR files are written to the output folder, fully offline.

• 100% offline — your research and pipeline output is never uploaded anywhere
• Produces .hdr files compatible with architectural lighting and rendering tools
• Useful for grayscale luminance maps in rendering workflows
• Bulk conversion of entire folders, including sub-folders, in one click
• Multi-core processing for fast handling of large batches
• Option to delete original PGM files automatically after conversion