Talk:JPEG File Interchange Format

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I changed the JFIF ID string from 'Always equals "JFIF\x00" (0x4A46494600)' to "JFIF (followed by a zero)", because that's what really appears. The \x0 prefix for a zero doesn't belong inside the quotes, if it's not really there in the ASCII. -SandyJax 20:26, 5 November 2007 (UTC)

[edit] JFIF vs. JPEG Interchange format - which one extends what?

The JPEG page states "The file format is known as 'JPEG Interchange Format', as specified in Annex B of the standard. This is often confused with the JPEG File Interchange Format (JFIF), a minimal version of the JPEG Interchange Format that was deliberately simplified so that it could be widely implemented and thus become the de-facto standard.", while the JFIF page states that JFIF is an extension of JPEG Interchange Format. So, what is it? Stolsvik (talk) 14:25, 11 January 2008 (UTC)

Depends on how you look at it. JFIF excludes certain options allowed in the formal JPEG standard (such as lossless JPEG, CMYK JPEG, etc.), but also packages JPEG data into a concrete file format (something which was not done in the formal JPEG standard itself), and makes provision for the inclusion of certain types of metadata (including a thumbnail)... AnonMoos (talk) 14:35, 11 January 2008 (UTC)

I regard the JPEG page to be correct. I tried to fix this page, using similar wording the the JFIF standard document. Stolsvik (talk) 15:13, 11 January 2008 (UTC)

The phrase 'minimal format for exchanging JPEG files' is not accurate - Firstly many programs will happily read a JIF file which has no JFIF segment whatsoever - Secondly JFIF is not a complete format for exchanging JPEG files since it doesn't define an absolute colour space.

Perhaps we could say that JFIF both extends and restricts the JPEG standard - It restricts use of things like CMYK and lossless images, but extends the standard by providing definitiions of relative color space, resolution/aspect ratio and component sample registration. --Ozhiker (talk) 15:55, 11 January 2008 (UTC)