Exif problem

[goldrian]

[C#, GdPicture.net 7]
No exif data is written into the image.... where is the problem?

Code: Select all

GdPictureImaging gdi = new GdPictureImaging();
gdi.SetLicenseNumber("XXXXXXXXXXXXXXXX");
string value = "testMaker";
int imgId = gdi.CreateGdPictureImageFromFile(@"C:\test.jpg");
string exifBefore = gdi.TagGetValueString(imgId, (int)GdPicture.Tags.TagExifMakerNote);
gdi.TagSetValueString(imgId, tag, TagType.TagTypeASCII, value);
string exifAfter =  gdi.TagGetValueString(imgId, (int)GdPicture.Tags.TagExifMakerNote);


Results:
exifBefore = ""
exifAfter = ""

Thanks.

[Loïc]

Hi,

you are using wrong argument for the TagGetValueString method.

The second parameter expect a tag index (just have a look on the reference guide).
So you have to brows all existing tags, check for the tagname, and when the tag name is matched just return its value.

See here for an example related to the xmlpacket: gdpicture-dotnet-code-samples/extracting-xmp-metadata-image-xml-file-t1992.html

Kind regards,

Loïc

[goldrian]

Thank you, now I understand ...
I did look at the reference guide but It wasn't enough for me
Thanks again

[Loïc]

You're welcome

[goldrian]

Ew....another problem... now that I correctly set the exif data, I see that, while in memory, the image contains all the tags, but when saved it lose them.
If I try to check the saved image reloading it or with an external exif reader program, it has no saved tags.
I've set a TagsSetPreserve(true), but no change.
Is there something else I'm missing from the reference guide?

PS: I'm saving using SaveAsJPEG(gdRef,filename, 100, true);

[goldrian]

Oh, well... If I save without "progressive" option it's ok!

SO:
SaveAsJPEG(gdRef,filename, 100, false); works

I don't know if that's a normal behaviour for "progressive" jpg , however I don't need them to be progressive, so that's a solution.
I leave this auto-answer here for others who can find the same problem