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Question

Auto rotating / orientation of photos

Forum|Forum|5 years ago
May 31, 2020
3 replies
8983 views

Hello,

as there are still some situations where the EXIF orientation flag is not interpreted correctly (older versions of Windows some software, some photo-displaying hardware, some homepages with photo upload functionality etc.), I have a couple of questions on auto rotating / orientation of photos:

1. In short: What is the best way to deal with photos that have an EXIF orientation flag which is not zero?

2. Is there a disadvantage, apart from the additional step in the work flow, when storing only physically correctly rotated images (using lossless rotation) on your hard drive / in your catalog?

3. Given there is a folder on the hard disk with pictures received via email, downloaded from the smartphone / camera etc. that is to be imported into the Elements catalog. Which options are there to lossless auto-rotate and optionally auto-replace all photos with a non-zero orientation flag during import, when already in the catalog and during export? I could not find any within Elements so far, but there has to be one as the catalog-concept of Elements does not allow to have the photos changed outside of Elements, especially when it comes to metadata change as this cannot be refreshed within the Elements catalog, unfortunately.

4. How can I tell Elements to disregard the orientation flag for image display so that I can visually check (and not using the orientation flag) whether any of my pictures is in danger of being displayed wrong?

Many thanks in advance for your help!

N

Neb1Author

Known Participant

So again, for anyone also coming across these thoughts:

1. Before doing anything to the photos (especially before importing) make sure, they are rotated with lossless transformation, the EXIF orientation flag is updated to 0 and the EXIF thumbnail is updated with the rotated image, while maintaining the date modified (if preferred) and then import to Elements.

2. No, but there are advantages.

3. Given the information in Organizer itself, on Adobe's Homepage, Google and the answers given here: I think this is again something that Elements badly lacks, unfortunately: No option for lossless batch rotation of jpegs. So you have to use another app, which is (a) sad that you have to install a lot of app to compensate essential features missing in Elements, (b) Elements doesn't really notice the change (no missing files, thumbnail is still correct, you can open the image, new orientation flag is properly displayed) but (c) I fear that reconnecting will be impossible once a small change in filename or something similiar occurrs as the metadata have changed and cannot be updated in the Elements catalog (again a basic feature that I can't understand is missing; cf. Lightroom: Metadata -> Read Metadata from Files).

So, if you want to batch rotate lossless: Irfanview Thumbnail, select all pictures in a folder, File -> JPG lossless operations -> Lossless rotation of selected images -> check "auto rotation", only "perfect" transformations, uncheck "write JFIF marker", done.

4. Again, you can't in Elements, and again, Irfanview Thumbnails will easily do the job.

MichelBParis

Legend

I'll try a short answer.

- I don't care at all for lossless rotation, because I never need it. What I need is that all pictures are displayed in portrait or landscape mode. I may also need that portraits are considered as landscapes for a number of batch resizing operations. There are thousands of posts on the web for that issue when you find just a few about lossless rotation.

- I never 'rotate' losslessly. I let the organizer assign the correct orientation with the 'rotate' button. That does not change any pixel, just the exif 'orientation' tag. You can test it and rotate a picture a hundred times, its size in kB does not change. No decompression, no lossy recompression.

- The real problem with jpeg is not rotation, it's decompression (necessary anyway to edit or output) followed by pixel or parametric editing which are not lossy until you recompress in jpeg format. If the recompression is done just with the correct value for the output, it's not an issue.

- There is no way I can 'auto rotate'. If I take photos with any of my cameras or smartphones with the focal plane parallel to the ground, there are no horizontals nor verticals; that depends only on the contents and my needs. Maybe some kind of AI can find an orientation solution to display many files correctly, but not for all. I am doomed to check and rotate manually according to my needs. The organizer lets me change the flag with one click of the rotate button.

- Even if I did choose to 'losslessly' rotate the pixels, I would not be able to detect a degradation visually.

- I want the organizer to keep the file pixels values unchanged and to record the 'orientation' value only in the catalog so that the thumbnails are displayed as I want. The information panel shows both the value of the orientation: 'normal' or 'Rotate 90'; it also shows the width and height in pixels, which is the other criteria for displaying in portrait or landscape mode. Try this: in a shot taken in portrait mode, create a version set with a landscape crop within the image. Look at the previous values. The 'Find by details (metadata) search can find portraits or landscapes, according to your choice. That lets you prepare batch resizing / cropping the same way with landscapes and rotated portraits.

- About editing the orientation flag outside the organizer: try to 'update thumbnails'. This has worked for me even if I don't know if that will work with any external editor.

- About reconnection: Changing metadata externally does not generally disconnect a file in a catalog. Reconnection, if needed is based on the same criteria as the filtering of duplicates: same date_taken plus same size in kilobytes. By the way, suppose the disconnection is caused by a move or rename, changing a flag would not change the size and prevent the reconnection.

I really would like to understand more about 'lossless rotation', but I don't see how that could help in my workflow and don't believe either in 'auto rotation' for my purposes.

N

Neb1Author

Known Participant

Just to be clear first, maybe there is a misunderstanding: With rotation, in this thread I am always referring to a rotation of whole-number multiples of 90°. Sorry, if that was too unclear.

MichelBParis said:

I really would like to understand more about 'lossless rotation', but I don't see how that could help in my workflow and don't believe either in 'auto rotation' for my purposes.

On lossless rotation:

To be honest, it's not that you would be alone with your opinion on lossless rotation, as I found out during my reserach on it. I don't need to convince anyone that everyone need lossless rotation, there is a reason, why on the other hand it is perfectly ok if people like to have it and if it is included in a photo organizing and manipulation software that sees itself on a certain level: In general, if you do picture manipulation, it is fair to go for the lossless solution rather than the lossy. It depends on the cost-benefit analysis. In this case, it is true, that in most cases the benefit is low (maybe there is a small one when it comes to printing or to very large 8k displays), but I think it is also true, that the cost are very low to just use lossless rotation rather than lossy when rotating. Let's turn it the other way round: What would be in general the benefit of a lossy rotation compared to a lossless one? (There is one, if lossless doesn't work, cf. MCU, but this is not the majority.)

On Auto-Rotation:

Take a bunch of pictures, some don't have the orientation you prefer for displaying it. Some of these again are displayed correctly if the automatically set orientation flag is considered for displaying. I agree, there are some special cases, where the flag doesn't help either, this then is as usual very advanced AI or plain manual action. So basically, auto-rotation reduces the amount of manual action.

On workflow:

I have also come across people saying I don't need to rotate, I just use proper software that can handle the orientation flag correctly. Again, you could follow this rule but then you might be missing something. Maybe that's not important for you, but it is fair if there are people that don't want to miss such things (special types of picture displaying hardware, software, homepages) and to have a picture library that is resilient in this way. Imagine if the computational power and energy ressources in a smartphone were high enough and rather than using the orientation flag, the smartphone would right away store the picture according to what it would it write in the orientation flag. It would then be automatically part of all our workflow and I can't see any disadvantage so far (maybe when it comes to resizing as you mentioned, but I believe (not completely sure yet) that with decent software, this could also be handled with rotated pictures).

(For a shorter period of time, I shot raw pictures and let it convert to jpg using Lightroom. I just found yesterday, that these picture are all with physically correct orientation, no flag. Unfortunately, I don't remember any more whether I ticked an option for that or whether LR did it as default.)

MichelBParis said:

- About reconnection: Changing metadata externally does not generally disconnect a file in a catalog. Reconnection, if needed is based on the same criteria as the filtering of duplicates: same date_taken plus same size in kilobytes. By the way, suppose the disconnection is caused by a move or rename, changing a flag would not change the size and prevent the reconnection.

Unfortunately, your criteria are not the only ones - I wish they were. E. g. I have found it to be impossible to reconnect a picture with a name that changed from *.JPG to *.jpg. See also my other post on reconnecting.

Sorry to say, but yes, lossless rotation including changing this orientation flag but applying no change to date taken and size prevents reconnecting, when you e. g. add an underscore to the filename. Updating thumbnails after rotation but before loosing the connection of course enables reconnecting again (btw, if you want to update all thumbnails in the catalog, you can also rename / delete thumb.5.cache in the root of your catalog folder).

Greg_S.

Community Expert

I'm not sure I fully understand your questions. But are you aware of the choice in the Organizer to rotate jpeg and TIFF files using Orientation Metadata? See Edit>Preferences>Files.

N

Neb1Author

Known Participant

Thank you. Yes, I am aware of this setting. I had it unchecked for the past 4 months, but I couldn't see any difference: All pictures, even the ones that would need a rotation, were displayed rotated in Organizer. If I turn now on and off, I don't see a difference, too. This might be caused by the fact that the thumbnails are already created and not affected by such a change now, as I said, there are photos that have been imported after unchecking and their view got rotated as if the box was checked.

As the four questions are still open, I would be interested in what part of my questions you are not sure whether you understood fully?

MichelBParis

Legend

Good questions.

I don't have the answers, so I searched the web for explanations and I found this description of how jpegs may be losslessly rotated:

https://www.betterjpeg.com/lossless-rotation.htm

As a matter of fact, I never had any issues in rotating files in the organizer except in the case of a bug in the photomerge panorama of PSE 14. The vertical component pictures had to be 'saved' before the merge could take place. I have always thought it was because in that PSE version the 'orientation' exif flag could not be read correctly.

Checking the 'lossy' degradation via comparison of layers in difference mode can tell you if the risk is real. With high compression and small picture sizes, the risk may exist.

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