Question Help!! GPS in EXIF using VB.NET!!

spanner5351 · #1 (**permalink**) 01-06-2009, 5:48 PM

Hi guys,

only just signed up here because i have been pulling my hair out trying to find answers all of the internet but to no avail!

As part of a project I am writing a program to be able to add GPS information to jpg pictures. For example to add the latitude and longitude to a photo.

So far i have managed to be able to change the latitude and longitude of jpg photos which already have these GPS field in the EXIF.

However...if i try to add the latitude and longitude information to photos that have never been tagged before i get the following error:

"Property cannot be found." on the following lines of code:

Dim latProp As PropertyItem = photo.GetPropertyItem(2)
Dim longProp As PropertyItem = photo.GetPropertyItem(4)

Ok so this to me means, that this photo does not have the above PropertyItems within it EXIF...

my question is....how do i add these PropertyItems to the file!!!???

any ideas!!?

oh and if i havent explained myself clearly, please let me know so i can clarify as i really do need to answers to this.

Thanks!!
-----
Information - Using Visual Studio 2005 and writing in vb.net

chahkuehtiao · #2 (**permalink**) 03-16-2009, 8:33 AM

I'm doing the exactly same project.
Can somebody help us?
it's urgent!

JohnH · #3 (**permalink**) 03-16-2009, 9:34 AM

Have a look in help for Image.SetPropertyItem Method, it's kind of weird.
You can also try this CodeProject: The ExifWorks class

spanner5351 · #4 (**permalink**) 03-16-2009, 9:46 AM

image.SetPropertyItem is fine for setting a field which exists. for example if a photo already has GPS data and you want to update it to a new coordinate, that will work.

However, if you try to set this property for a photo that has never had GPS data within it, it will fail and say that this field does not exist.

chahkuehtiao · #5 (**permalink**) 03-16-2009, 10:25 AM

Quote:

Originally Posted by spanner5351

image.SetPropertyItem is fine for setting a field which exists. for example if a photo already has GPS data and you want to update it to a new coordinate, that will work.

However, if you try to set this property for a photo that has never had GPS data within it, it will fail and say that this field does not exist.

That's right , what I want to do is add GPS field within the EXIF.
Pls help me..

spanner5351 · #6 (**permalink**) 03-16-2009, 10:29 AM

are you doing this for a school project?

chahkuehtiao · #7 (**permalink**) 03-16-2009, 11:12 AM

yup..
but I not good at programming..
headache of it..

InertiaM · #8 (**permalink**) 03-16-2009, 11:22 AM

I'll start you off.

Code:

    Private Function CreatePropertyItem() As PropertyItem
        Dim ci As System.Reflection.ConstructorInfo = GetType(PropertyItem).GetConstructor(BindingFlags.NonPublic Or BindingFlags.Instance Or BindingFlags.Public, Nothing, New Type() {}, Nothing)
        Return DirectCast(ci.Invoke(Nothing), PropertyItem)
    End Function

Now you should be able to program or Google the rest

chahkuehtiao · #9 (**permalink**) 03-16-2009, 11:29 AM

Quote:

Originally Posted by InertiaM

I'll start you off.

Code:

    Private Function CreatePropertyItem() As PropertyItem
        Dim ci As System.Reflection.ConstructorInfo = GetType(PropertyItem).GetConstructor(BindingFlags.NonPublic Or BindingFlags.Instance Or BindingFlags.Public, Nothing, New Type() {}, Nothing)
        Return DirectCast(ci.Invoke(Nothing), PropertyItem)
    End Function

Now you should be able to program or Google the rest

ok, thanks. I'll try it.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)