Transform vs Rotate

[jrogers]

I am wondering what the difference is between your EXIF transform and a manual rotate. My current editing software (Jasc AfterShot) seems to display thumbnails properly when I manually rotate using cam2pc, but when I automatically transform, the jask thumbnails are shown in the original orientation. Strangely, when I edit the images in AfterShot, they are correctly oriented (as they are in the other software I use,including explorer) so I'm sure its not a problem with cam2pc, but I thought I'd ask so as to assist Jasc in debugging the issue.

Thanks for any info - great product!

[nabocorp]

Hello,

although I do not know AfterShot's internals I am going to try to give an explanation.

Along with the EXIF metadata most cameras do save an EXIF thumbnail. If your camera saves the EXIF orientation (an info telling if the camera was rotated when the shot was taken or not), and it seems to, then AfterShot (which probably uses the EXIF thumbnail) is even able to rotate the EXIF thumbnail while displaying it so you get the good result.

When you auto transform the pictures in cam2pc, cam2pc rotates the image, updates the orientation information (to say that the image is oriented properly) but does NOT rotate the EXIF thumbnail. Mainly because this is quite tricky to do (maybe in next version).

So AfterShot reads the EXIF thumbnail (which is not oriented properly) and the EXIF orientation tells him that the image is oriented properly. So AfterShot just displays the thumbnail as is and there you have the mis-orientation.

If you edit the image in AfterShot or display it in Internet Explorer, then the EXIF thumbnail is not read: the whole image is used and this has been updated by cam2pc so it's normal it is displayed correctly.

In fact most softwares do not update EXIF orientation and/or EXIF thumbnail properly when losslessly rotating a JPEG. That's why in cam2pc we chose NOT to use the EXIF thumbnail of an image to create the thumbnail in the Image Browser but to read the image and scale it down. If we had used the EXIF thumbnail, cam2pc Image Browser could have been even faster that it is now but with the risk of displaying badly oriented thumbnails.

Hope that this is clear enough!
nabocorp

[jrogers]

Very clear - thanks.

[nabocorp]

Forgot to mention one thing. If you edit an image (crop, retouch or whatever) then most softwares will drop the EXIF metadata when you save it. In that case there is no more an EXIF thumbnail available and AfterShot has no other choice then reading the image and scaling it down to get the thumbnail.