Convert NEF to ICO

The Nikon Electronic Format (NEF) is a proprietary raw image container exclusively used by Nikon digital cameras, structured around the TIFF (Tagged Image File Format) specification. It stores raw 12-bit or 14-bit data captured by the image sensor without in-camera processing, alongside extensive metadata including EXIF data, Picture Control settings, and lens identification. The format supports both lossless and lossy compression variations and encapsulates a full-resolution JPEG preview within the file structure for quick referencing.

Microsoft Windows (with the Microsoft Camera Codec Pack) and macOS Preview offer native support for viewing NEF files. For professional editing and raw conversion, Nikon provides the proprietary NX Studio software. Third-party industry-standard applications such as Adobe Photoshop, Corel AfterShot Pro, and the open-source editor GIMP (utilizing Darktable or RawTherapee as a backend) allow for manipulation of the raw sensor data.

The ICO format is an image container specifically designed for Microsoft Windows to store icons for executable files, folders, and applications. Introduced with Windows 1.0, it can encapsulate multiple raster images of varying dimensions and color depths (specifically BMP or PNG frames) within a single file to support dynamic scaling across different display resolutions. The structure comprises an ICONDIR header referencing one or more ICONDIRENTRY directory entries, allowing the operating system to select the appropriate 16x16, 32x32, or 48x48 pixel resource based on the current UI scaling settings.

ICO files are natively supported by the Microsoft Windows operating system, which automatically renders them in the File Explorer and taskbar. On macOS, Apple Preview handles the format natively. For editing or detailed inspection of the contained bitmap layers, raster graphics editors such as GIMP, Adobe Photoshop (via plugin), or Paint.NET are required. Web browsers also natively render ICO files when they are designated as favicons.