HDR to PNM — Online Image Converter
Convert HDR to PNM online. Private, client-side — no uploadrequired. Fast batch converter.
About HDR to PNM
Convert HDR to PNM. HDR (Radiance RGBE) stores high-dynamic-range lighting with 32 bits per pixel. PNM is the Netpbm envelope that auto-selects PBM, PGM, or PPM by content. Readers map it to the underlying bitmap type before conversion..
Why convert HDR to PNM?
- Larger files than lossy shares with PNM uncompressed quality.
- Keep quality where supported.
- Private, no upload - runs in your browser.
HDR vs PNM
| Animation | No | No |
|---|---|---|
| Transparency | No | No |
| Compression | lossless high dynamic range | uncompressed |
| Typical use | HDR (Radiance RGBE) stores high-dynamic-range lighting with 32 bits per pixel. | PNM is the Netpbm envelope that auto-selects PBM, PGM, or PPM by content. |
When not to convert HDR to PNM
- Skip PNM for the smallest share: lossless output stays large, so prefer a lossy target when sending HDR files.
- Keep a master copy: repeated exports stack small losses, so archive HDR before batch PNM shares.
Limits
Starting point: HDR - HDR (Radiance RGBE) stores high-dynamic-range lighting with 32 bits per pixel. Tone mapping compresses highlights into display range on export. Readers map it to the underlying bitmap type before conversion. Export PNM from HDR at matched dimensions; every pixel maps across, so large sources stay large.
How conversion works
Conversion runs entirely in your browser with the WASM image engine. Files never leave your device.