Detect JPEG File Interchange Format (JFIF)

[odan]

Details

• https://en.wikipedia.org/wiki/JPEG_File_Interchange_Format
• http://fileformats.archiveteam.org/wiki/JFIF

Examples

• http://netghost.narod.ru/gff/sample/images/jfif/index.htm
• https://unsplash.com/photos/WRIsWAI13H4

Identification

It uses Application Segment #0, with a segment header consisting of the null-terminated string spelling "JFIF" in ASCII followed by a byte equal to 0, and specifies that this must be the first segment in the file, hence making it simple to recognize a JFIF file.

Valid JFIF files begin with FF D8 FF E0 ?? ?? 'J' 'F' 'I' 'F' 00. Some technically-invalid files exist in which the JFIF segment has been relocated, and for them this signature will not match.

[odan]

This is technically the same as JPEG. Also the header is the same.