Canon Highlight Tone Priority
|Status:||Assigned||Start date:||17 Mar 2013|
|Assignee:||Ben Touchette||% Done:|
|Category:||exif||Estimated time:||10.00 hours|
Recent Canon camera's have a feature called Highlight Tone Priority (HTP), which is described as such:
"Highlight tone priority shoots at an ISO speed one stop lower (1ev underexposure) then compensates for this in RAW processing."
Currently it seems Exiv2 can't tell us if a file was shot with HTP On or Off.
On a side note ExifTool apparently can read the HTP status:
$ exiftool HTP.CR2 | grep -i highlight
Highlight Tone Priority : Enable
Pascal de Bruijn
#1 Updated by Robin Mills almost 4 years ago
- Status changed from New to Assigned
- Assignee set to Niels Kristian Bech Jensen
- Priority changed from Low to Normal
- Target version set to 0.24
May I ask you to take a look at this. Pascal works on DarkTable - a really awesome open-source project. I feel guilty that I haven't picked this up already. I'm a little overwhelmed at the moment (especially with Google Summer of Code). If you can't deal with this, please assign this back to me.
#10 Updated by Pascal de Bruijn 8 months ago
So I don't own a Canon camera with HTP, but I asked around and I got permission to supply you with these:
(from a 7D and a 5DmkII, courtesy of andabata)
(from an 80D, courtesy of dabbill)
#12 Updated by Robin Mills 5 months ago
- Assignee changed from Robin Mills to Ben Touchette
- Target version changed from 0.26 to 0.27
- % Done changed from 0 to 50
- Estimated time set to 10.00
Reading and writing those tags isn't simple and I've never worked in the MakerNote decode/encode code. Raphael is working on #1219 and I think he's going to visit me in England in October. We'll discuss all of these issues when he's here. I know that Shridar is very anxious for #1203 to be included in v0.26. It may be possible to include fixes for all three issues in v0.26, however the project is already at feature complete.
#13 Updated by Robin Mills 5 months ago
I've built and reviewed your code. What you have done looks about right to me. It's reporting lots of metadata that has never seen the light of day before. The following parts of the test suite have been disturbed by this:
651 rmills@rmillsmbp:~/gnu/exiv2/trunk $ make tests | grep differ Files test/tmp/bugfixes-test.out-stripped and trunk/test/data/bugfixes-test.out differ Files test/tmp/exifdata-test.out and test/data/exifdata-test.out differ Files test/tmp/exiv2-test.out and test/data/exiv2-test.out differ Copy all tests...... Files test/tmp/table.jpg.c3tst and test/data/table.jpg.c3gd differ Files test/tmp/smiley1.jpg.c3tst and test/data/smiley1.jpg.c3gd differ Files test/tmp/write-test.out and test/data/write-test.out differ 652 rmills@rmillsmbp:~/gnu/exiv2/trunk $We're going to have to defer this at the moment.
Incidentally, I had to edit the patch to have it respected by SVN. The preferred way to make a patch is to use:
$ cd ~/gnu/exiv2/trunk $ svn diff . > foo.patchThanks for working on this.