EXF

The exf file extension is related to CostX program solutions used to prepare estimates, bills of quantities in construction industry, developed by Exactal Technologies.

The exf file contains data in default CostX data exchange format.

The exf file extension is related to ExactFile file integrity verification tool for Microsoft Windows operating system, developed by StudyLamp Software.

The exf file used in the program contains checksum digest data.

The exf file extension is also related to Exchangeable Image File Format.

Exif (despite being an acronynm it is usually written as "Exif" rather than "EXIF") is a file format developed by the Japan Electronic Industry Development Association (JEIDA) principally for use by digital cameras. The specification uses the JPEG, TIFF and RIFF formats, with the addition of metadata tags.

There are some issues with the Exif format, including:

•  If Exif files are read by programs other than the original manufacturer, their maybe metadata (data describing the image) which can not be read, and which becomes corrupt or lost if the file is then re-saved in Exif format.
•  The standard defines a markernote tag which manufacturers can use to store any data they wish in. As this tag is proprietary and manufacturer specific, it is difficult, if not impossible to read this information or preserve when re-saving the image.
•  Exif is limited to 24 bit color depth.
•  Exif has no provision for video.