Hi Phil,
I have just found intersting article here:
http://keyj.emphy.de/exif-orientation-rant/it is all about
orientation TAG issue.
I would like to solve it once for all for the users of my software.
Here is the scenario.
1.
From "normal" or raw images I already extract preview image if available and save/convert it to 100% quality jpg.
If preview is not available raw image is processed and 100% quality jpeg is created.
User has an option to process raw images regardless the state of preview image.
2.
I extract Orientation information from image if available.
A small issue here is that I have found that there is Transformation tag as well.
From your documentation I understand that
Orientation IFD0 = Transformation IFD0 +1
Is this another EXIF misuse by big brand names or what ?
Eventually I end up with some OrientTransf information upon which I rotate image and save it as 100% quality jpg image.
(I am aware that from purist point of view some quality is lost here but for my mission is negligible).
3. User sees image displayed and if he/she is not happy rotation tool is available.
4. And now I would like to create new image from scratch where:
- image from step 1. is used,
- thumbnail image is created (just not sure about typical size of thumbnail image - can you enlighten me a bit)
- Thumbnail image is inserted,
- Relevant EXIF and GPS tags are written with Orientation value IFDO = 1
The questions:
- Is there a command in EXIFtool to insert Thumbnail image in existing image ?
- Is there a command in EXIFtool to set Thumbnail Orientation tag to 1 ?
Best,
Dusan