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Permlink Replies: 9 - Pages: 1 - Last Post: 4 Jan 21, 11:47 Last Post By: davidekholm Threads: [ Previous | Next ]
romaya

Posts: 19
Registered: 10-Jan-2016
Reflection codes in exif orientation tag not supported by jAlbum
Posted: 1 Jan 21, 17:32
 
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Attachment O7.jpg (71.2 KB)
Attachment O5.jpg (71.0 KB)
Attachment O4.jpg (71.0 KB)
Attachment O2.jpg (70.9 KB)
Attachment O1.jpg (69.0 KB)
I have recently noticed that the exif tags for orientation are not fully supported in jAlbum. In particular, the reflected codes are not supported,

The exif orientation codes are numbered 1 to 8, with 1, 3, 6 and 8 being cardinal rotations (0, 90, 180 and 270 degrees). These are supported by jAlbum. The remaining codes 2, 4, 5 and 7 are reflections of those rotations but these are not supported by jAlbum (although they are supported by Windows 10 FileExplorer, Windows "Paint" & Adobe Photoshop).

As an example I have attached files O1.jpg, O2.jpg, O4.jpg, O5.jpg and O7.jpg, which should all appear as an upright, unreflected 'F' providing the embedded exif rotation codes are correctly interpreted. However, although those files all appear correctly in Windows 10 FileExplorer, Paint and Photoshop, only O1.jpg is correctly interpreted by jAlbum v23.1,

I know that you can manually adjust the rotation and reflection of individual images within jAlbum, but it may not always be apparent that a particular image should in fact be rotated, so if jAlbum could be updated to reflect the exif orientation flag correctly I feel it would be a great advantage.
davidekholm

Posts: 3,442
Registered: 18-Oct-2002
Re: Reflection codes in exif orientation tag not supported by jAlbum
Posted: 3 Jan 21, 15:00   in response to: romaya in response to: romaya
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Thanks for posting. We're aware that these specific "mirrored" orientation types aren't supported today. It shouldn't be hard to support these, but it hasn't been requested before so I just wonder how common these files are?
JeffTucker

Posts: 8,039
Registered: 31-Jan-2006
Re: Reflection codes in exif orientation tag not supported by jAlbum
Posted: 3 Jan 21, 15:15   in response to: davidekholm in response to: davidekholm
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davidekholm wrote:
...I just wonder how common these files are?

I've never encountered such a file "in the wild," but I've seen them in one particular spot. One of the primary school teachers (from one of the Belgian or Dutch schools - I don't recall which) often posted online albums with "flipped" images. It was easy to tell because the kids often wear shirts or hoodies with text on them, and the text was reversed:

NIKE


I was puzzled by it - I don't know how I could persuade my DSLR or my phone to produce such images!

I haven't seen it in the last year or more, however, so whatever that teacher was doing, he or she has fixed it. ;)
romaya

Posts: 19
Registered: 10-Jan-2016
Re: Reflection codes in exif orientation tag not supported by jAlbum
Posted: 3 Jan 21, 19:02   in response to: romaya in response to: romaya
 
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The reason I use these mirrored exif orientation codes is to correct the automatic reflection of "selfie" images recorded on phones & tablets. The default setting on most mobile devices is to mirror selfies, which can be annoying if there is any obvious lettering in the image. So I use the "exiftool" application to automatically mirror those images back to the real-world appearance. I prefer this method as it is a lossless way of achieving such a transformation without having to read the jpg into an editor, flip it and save it out again.

I realise that these reflection codes are probably a rare ocurrence but since jAlbum already supports the straight rotations it would be useful if full support for those codes could be provided.
JeffTucker

Posts: 8,039
Registered: 31-Jan-2006
Re: Reflection codes in exif orientation tag not supported by jAlbum
Posted: 3 Jan 21, 19:22   in response to: romaya in response to: romaya
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Interesting. I don't have a tablet, but on my aging Galaxy S7, the preview of a selfie is flipped, but the saved image is shown in the correct orientation. There is a setting to change that, but "save as previewed" isn't the default.
romaya

Posts: 19
Registered: 10-Jan-2016
Re: Reflection codes in exif orientation tag not supported by jAlbum
Posted: 3 Jan 21, 19:31   in response to: JeffTucker in response to: JeffTucker
 
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We have a Samsung Galaxy A3 and a Tab S6. On both these devices the default is to save mirrored selfie images. I only noticed this recently so that is why I have a back-catalogue of reflected images,

The "save as previewed" setting does seem to correct the saved images.
davidekholm

Posts: 3,442
Registered: 18-Oct-2002
Re: Reflection codes in exif orientation tag not supported by jAlbum
Posted: 4 Jan 21, 10:39   in response to: romaya in response to: romaya
 
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Please try doing a core update (Tools->External tools->jAlbum core update) and restart jAlbum when prompted. It should now handle flipped images too (although rotating them currently feels counter-intuitive).

I haven't implemented a flip button yet, but if you wish to flip the currently selected image, then open the system console and issue (Groovy) :
selected.orientation = selected.orientation.flipped()
romaya

Posts: 19
Registered: 10-Jan-2016
Re: Reflection codes in exif orientation tag not supported by jAlbum
Posted: 4 Jan 21, 10:56   in response to: davidekholm in response to: davidekholm
 
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David - many thanks for such a prompt update. All the exif orientation tags are now expressed correctly - and the system console suggestion works too.
romaya

Posts: 19
Registered: 10-Jan-2016
Re: Reflection codes in exif orientation tag not supported by jAlbum
Posted: 4 Jan 21, 10:57   in response to: romaya in response to: romaya
 
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Impressed by the swift resolution of this update request.
Great work jAlbum
davidekholm

Posts: 3,442
Registered: 18-Oct-2002
Re: Reflection codes in exif orientation tag not supported by jAlbum
Posted: 4 Jan 21, 11:47   in response to: romaya in response to: romaya
 
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Thanks :-)
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