Questions to Rotation of images

[herb]

Hello Pierre,

I am working with XnViewMP version 1.00 on a windows 10 system.

I want to rotate a *.jpg image from an Olympus OMD 5 mkIII.
Such an image contains a thumbnail image and also a preview image (inside trailer).

For rotation I have checked: Tools --> Settings --> Browser --> Misc. : "change EXIF orientation ONLY" is checked.
But clicking on Tools --> JPEG lossless transformations --> Rotate xxx
does not only rewrite/change the EXIF orientation tag.
The image is rotated and orientation is set to: Horizontal (normal) == top left.

(1)
What did I wrong, that the image is rotated, but NOT using the orienation tag?

(2)
I have seen that the preview image (inside trailer) does not exist anymore.
Exiftool generates an error message for this tag.
Is it by design or is it an error?

Thanks for your help in advance
Best regards
herb

[xnview]

this setting is used by rotate in browser mode not "JPEG lossless transformations " which make always a lossless rotation

[herb]

Hello Pierre,

thanks for your reply.
I was in browser, selected the thumbnail and opened the menu.

Now I learn: In browser-mode, using the toolbar command (and only this) will do what I want.
Thanks for your help.

Sorry to ask again:
Can we save the preview image using JPEG lossless transformations.

Best regards
herb

[xnview]

Can we save the preview image using JPEG lossless transformations.

you means the embedded thumbnail?

[herb]

Hello Pierre,

*.jpg images made by Olympus cameras have 2 embedded images:
- a (smaller) thumbnail image inside the IFD
- a (bigger) preview image inside the trailer
Both embedded images are *.jpg images.

My question is for preview image

Best regards
herb

[helmut]

Until now I thought that you (Herb) have only problems with the German translation.

[xnview]

could you send me a sample file? Currently only thumbnail is processed

[herb]

Hello Pierre,

thanks for your investigations.
I sent such an image via mail.

Best regards
herb

[XnTriq]

Related topics:

Olympus also “injects” a “preview image” in addtion to the embedded Exif thumbnail (see Image Samples).

We all know that many image files contain embedded thumbnails in the EXIF data; this is also the case here, and the thumbnail size is 120×160 pixels. It is not a common knowledge, however, that Olympus files (ORF or full-size JPEG type) also contain a smaller version of a JPEG, used for in-camera, magnified preview. This image is 1200×1600 pixels (approximately 2 MP). It is quite heavily compressed, usually to 300..400 kB, which gives a compression ratio of 1:15..1:20.

During the picture review, the E-510 does not show the original image, but a special "preview image" stored additionally inside the image file (see File Format and compression above). That "preview image" is 1600×1200 pixels. This means that when you view it on the monitor (320×240 pixels) in a 5× magnification, it shows already all information available. Higher magnifications add just enlargement, without any more detail. They also amplify all compression losses and artifacts, and the "preview image" is quite heavily compressed.

• Nikon Coolpix L10
  • Full-res: 2560×1920
  • Preview: 320×240
  • Thumbnail: 160×120
• Olympus E-510
  • Full-res: 3648×2736
  • Preview: 1600×1200
  • Thumbnail: 160×120
• Sony DSC-W730
  • Full-res: 4608×3456
  • Preview: 1440×1080
  • Thumbnail: 160×120