2004.10.01 07:22 "[Tiff] BigTIFF extension issue", by Joris Van Damme

2004.10.04 14:21 "Re: [Tiff] Re: BigTIFF extension issue", by Joris Van Damme

I'm curious - can you name some examples please. I'd be interested in hearing about some and seeing exactly what the differences are/were between 'changes'.

The BMP format is an example of a format which has been extended without breaking a lot of existing software. Recently BMP v3 was introduced. This was possible because the additions were made in a portion of the file header which can be skipped based on an offset value which appears early in the header. Properly written old readers should automatically skip the new stuff (in practice some readers were broken).

A very fine example... on how the extension remained unchanged, because it was still regarded the same file format. A very fine example, too, on how even much more drastic changes to the format's specification, still do not suffice to regard the new version as a different format.

I believe the point of view you defend is that the extension should be changed.

If you go back, you'll see that Andy was responding to Chris saying companies do sometimes change extension when brewing a next version of a format. Thus, he was asking for examples that involved changing the extension. Possibly, but not certainly, and I'm not quoting him on this but going a long way interpreting, he was trying to make the point that most of the proper examples that could be given involve a single company.

Joris Van Damme
Download your free TIFF tag viewer for windows here: