Convert RAF to PPM / PNM

The RAF extension identifies a raw image file generated by Fujifilm digital cameras. It contains unprocessed data directly from the camera's image sensor-typically Fujifilm's proprietary X-Trans CMOS or standard Bayer filter arrays-along with a JPEG preview and Exif metadata. The file structure encapsulates the sensor's exact luminance values and color information before demosaicing or gamma correction is applied. This format allows for extensive post-processing flexibility regarding white balance, exposure, and color grading compared to compressed formats.

To view or edit RAF files, users require software capable of interpreting the specific sensor data mapped in the file header. Fujifilm provides 'Fujifilm X RAW STUDIO' for native processing. Industry-standard applications such as Adobe Lightroom Classic, Capture One, and the open-source RawTherapee support RAF decoding. Microsoft Windows users may need to install the 'Raw Image Extension' package, while macOS Preview possesses built-in support for most RAF iterations via Apple's Core Image framework.

The Portable Pixel Map (PPM) format is a lowest-common-denominator color image format developed by Jef Poskanzer as part of the Netpbm project. It stores pixels as uncompressed RGB triplets (Red, Green, Blue) in either a plain ASCII text format (P3 header) or a more efficient binary format (P6 header). The file structure is extremely minimal, consisting of a magic number identifier, dimensions (width and height), maximum color value, and the pixel data itself, making it easily parsable by simple scripts but inefficient for storage compared to compressed formats like JPEG or PNG.

Native support for PPM files is absent in standard Windows or macOS photo viewers. Users typically require specialized image manipulation software to view or convert these files. GIMP (GNU Image Manipulation Program) and IrfanView are the primary tools for opening PPM files on desktop environments. On Linux systems, the Netpbm toolkit and ImageMagick suite provide command-line utilities for processing and converting PPM data.