Error in docs about "file creation date"

[Ian Wood]

On 22 May 2007, at 23:30, Wilhelm Sanke wrote:

> These are indeed valid arguments that have to be considered .
>
> As far as I know, however, the situation may be at least different  
> for Windows and MacOS. I do not know if the OSX finder could access  
> EXIF data automatically, but WindowsXP surely does.

> The EXIF creation date of a camera image is automatically read by  
> WindowsXP, as can be seen in the file information when you  
> configure the folder setting accordingly. So there would be no  
> slowdown of any kind when incorporating this information in the  
> detailed files.
> I am not really sure what the OSX finder does. If in fact it should  
> be able to access such data, then I would repeat my recommendation  
> for the detailed files.

'Get Info' in the Finder (at least on 10.4.9) shows the manufacturer,  
model, colour space, profile, focal length and shutter speed for  
images with EXIF info. Spotlight allows you to search by lots of  
other EXIF tags, although I've not seen an EXIF creation date in the  
list.

However, you can *never* assume that EXIF data is present in an image  
file - many photographers use special EXIF-stripping utilities before  
uploading files to webservers if for some reason they don't want the  
client to know things like the time the shot was taken.
Obviously this isn't a problem for images that have been 'saved as'  
with the EXIF data stripped out because they will have a new valid  
creation date being new files, but people do it to original files as  
well (or copies if they know what's good for them...).

> If not, then - as the main purpose of this discussion was about  
> including valid creation date information  in Metacard/Revolution  
> applications - we should tweak Alex Tweedly's "libEXIF" stack to  
> produce a handy function to include a reliable creation date  
> information  in our stacks if needed.

It's not as trivial as it may sound.
I work with a lot of programs that deal with EXIF data, and many of  
them store it differently, especially when it comes to images that  
started off as RAW files. Plus you'd have to try and decode the two  
gazzillion different RAW formats that are the result of a different  
file format for *every* camera model of *every* manufacturer...


I'm probably coming across as really negative, but EXIF data is  
nowhere near as straightforward a topic as it first appears. :-(

Ian