Re: DateTime and DateTimeOriginal??

[Larry Ewing <lewing novell com>]

>From the exif 2.2 spec

        DateTime
        The date and time of image creation. In this standard it is the
        date and time the file was changed. 
        
        DateTimeOriginal
        The date and time when the original image data was generated.
        For a DSC the date and time the picture was taken are recorded. 
        
        DateTimeDigitized
        The date and time when the image was stored as digital data. If,
        for example, an image was captured by DSC and at the same
        time the file was recorded, then the DateTimeOriginal and
        DateTimeDigitized will have the same contents. 
        
DateTime and DateTimeOriginal should be different if the image has ever
been edited.  Perhaps you were confused since in Most cases
DateTimeOriginal and DateTimeDigitized will be the same.
DateTimeDigitized is meant to be used to mark the Time Film was scanned
into a digital form, if the image started out in digital form it should
be the same as DateTimeOriginal

I very intentionally change DateTime each time the file is modified in
F-Spot.

--Larry

On Wed, 2005-08-17 at 23:10 +0900, Bengt Thuree wrote:
> Hej
> 
> I saw somewhere that the DateTime and DateTimeOriginal should be equal in
> the EXIF 2.1 tags.
> 
> But the DateTimeDigitized could be different.
> 
> Is this true?
> 
> Since I found the following in JpegFile.cs which indicates that the
> DateTime will be reset to the last time the EXIF data was modified.
> 
> // set the write time in the datetime tag
> image_content.GetEntry (Exif.Tag.DateTime).Reset ();
> 
> /Bengt
>