Convert PEF to ICO

The Pentax Electronic File (PEF) is a proprietary raw image format developed by Pentax (now a subsidiary of Ricoh) for its digital single-lens reflex (DSLR) cameras. Based on the TIFF (Tagged Image File Format) structure/EP standard, PEF files store unprocessed sensor data captured directly from the camera's CCD or CMOS sensor, retaining a higher dynamic range and color depth (12-bit or 14-bit) than compressed JPEG counterparts. The format encompasses metadata such as ISO settings, shutter speed, and white balance, often employing proprietary lossless compression to manage file size while preserving absolute data integrity for post-processing.

Operating systems including Windows and macOS offer limited native previewing of PEF files through built-in raw codec packs, though support varies by camera model. For comprehensive editing and non-destructive processing, dedicated raw converters are required. Adobe Lightroom and Adobe Camera Raw are the industry standards for PEF manipulation; free open-source alternatives such as Darktable and RawTherapee utilize the dcraw library to interpret the specific 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.