Word Form - Extract Exif Data from JPEG

Question

Hello,

I have crated a form on which I have an image control.

Once I have selected an image, I want to populate some text content controls with metadata from the image.

Of course, first I need to locate and extract the metadata out of the file.

I am working through a document at https://www.media.mit.edu/pia/Research/deepview/exif.html.

It discusses Image File Directories which contain a number of entries.

Each entry contains: 

    Tag Number

    Data Format (which tells you # of bytes / component)

    Number of Components

    Data Value or Offset

        If data < 4 bytes = data

        if data > 4 bytes = offset to data

I follow all of this until I get to the offset.  If the number of bytes / component is 1 (for example a string) and the number of components is 26 (> 4 bytes) then the last item in the entry is an offset.

My question is, what is this offset relative to?

Any input would be greatly appreciated.

Best Regards,

Chris

***Post moved by the moderator to the appropriate forum category.***

Answer 1

Hello,

After working thru the JPEG file with a Hex editor it appears that the offset is relative to the first byte of the Tiff header.

Chris