Bug 381821 - Wrong value on high ISO settings & fix Exposure value formatting
Summary: Wrong value on high ISO settings & fix Exposure value formatting
Status: RESOLVED WORKSFORME
Alias: None
Product: frameworks-kfilemetadata
Classification: Frameworks and Libraries
Component: general (show other bugs)
Version: unspecified
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: Pinak Ahuja
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-06-30 11:19 UTC by Pekka Helenius
Modified: 2019-08-08 04:33 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:


Attachments
Fix for high ISO values & reformat Exposure tag (1.85 KB, patch)
2017-06-30 11:19 UTC, Pekka Helenius
Details

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Description Pekka Helenius 2017-06-30 11:19:15 UTC
Created attachment 106386 [details]
Fix for high ISO values & reformat Exposure tag

I don't know should I open two separate issues for these. Anyway,

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1) Wrong ISO value reported on high ISO settings

- kfilemetadata reports wrong ISO value (65535) if extreme ISO settings like 102400 is used.

This is because kfilemetadata exiv2extractor receives the value from "Exif.Photo.ISOSpeedRatings" tag, which is, according to Exiv2 documentation, a short integer, with a maximum limit of 65535. Obviously, ISO speed such as 102400 exceeds the limit and thus wrong value is set. This tag is specified in ISO 12232 standard.

Instead of Exif.Photo.ISOSpeedRatings", ISO value can be retrieved from ""Exif.Photo.RecommendedExposureIndex" tag, at least for some cameras.

ExposureIndex tag gives correct ISO values at least for Canon 5D Mark 3 RAW images (all ISO values tested and checked, including CR2 -> Adobe DNG conversion files).

NOTE: I'm not sure whether RecommendedExposureIndex is registered by all camera models or not so I can't be 100% sure if it can be used. Another small issue with the index value is that decimal separator is missing in Dolphin (which I think can easily be fixed).

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2) Exposure tag format

I find it extremely annoying how kfilemetadata currently handles "Exif.Photo.ExposureTime" tag. Values such as 0.0008 are not very informative while a camera can report 1/8000 for the same picture. After all, as a photographer, I want get equivalent and good reference values for the ones used in cameras.

The issue is caused by "QVariant::Double" which is used for Exposure tag in exiv2extractor.cpp. Replacing it with "QVariant::String" fixes the issue.

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Proposed patch file for these issues as an attachment.
Comment 1 Alexander Stippich 2019-06-14 19:25:04 UTC
second part is fixed by https://phabricator.kde.org/R286:2dc250bc9239d9f30f55110f4b3b8329c202a5c3
Comment 2 Alexander Stippich 2019-06-30 07:06:22 UTC
Are you able to provide a test file for issue 1?
Comment 3 Alexander Stippich 2019-07-09 17:50:52 UTC
Since the provided patch does not work for every file, I need a file for testing a solution that works for everyone. If you have such a file, please upload it.
Comment 4 Bug Janitor Service 2019-07-24 04:33:08 UTC
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

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Comment 5 Bug Janitor Service 2019-08-08 04:33:10 UTC
This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!