Convert NEF to JBIG

Understanding NEF and JBIG file formats

NEF (Nikon Electronic Format) is a proprietary raw image format used by Nikon digital cameras. It stores unprocessed image data directly from the camera's sensor, preserving maximum detail and allowing for extensive post-processing. JBIG (Joint Bi-level Image Experts Group) is a compressed image format designed for bi-level (black and white) images, commonly used in fax machines and document imaging systems. JBIG offers efficient lossless compression for monochrome images but is not suitable for color or grayscale photographs.

Why convert NEF to JBIG?

Converting a NEF file to JBIG is rare, as NEF is a high-quality photographic format and JBIG is intended for bi-level images. However, if you need to use a Nikon photo in a document imaging system that only supports JBIG, conversion may be necessary. Note that this process will convert your photo to black and white and may result in significant loss of detail and color information.

How to convert NEF to JBIG

There is no direct NEF to JBIG converter, so you must use a two-step process:

1. Convert NEF to a standard image format (such as TIFF or PNG) using a photo editor or raw converter.
2. Convert the intermediate image to JBIG using a specialized tool.

Recommended software for conversion

• Adobe Photoshop: Open the NEF file, convert it to grayscale, and export as TIFF or PNG (File → Save As).
• RawTherapee or darktable: Free raw converters to export NEF as TIFF or PNG.
• ImageMagick: Use the convert command to process the intermediate file to 1-bit and then to JBIG:
  convert input.tif -threshold 50% output.jbg
• jbigkit: A command-line tool for encoding images to JBIG format.

Step-by-step conversion example

1. Open your NEF file in RawTherapee and export it as a grayscale TIFF.
2. Use ImageMagick to threshold the TIFF and convert it to JBIG:
   convert photo.tif -threshold 50% photo.jbg

Considerations and tips

• Quality loss: The conversion will reduce your image to black and white, losing all color and most detail.
• Best use case: Only convert NEF to JBIG if you specifically need a bi-level image for document processing.
• Backup: Always keep your original NEF files for future editing or printing.