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rcharbon · 03-31-2024, 07:40 PM

TIL that images can contain EXIF data to set orientation. The 8 EXIF orientation values are numbered 1 to 8:
1= 0 degrees: the correct orientation, no adjustment is required.
2= 0 degrees, mirrored: image has been flipped back-to-front.
3= 180 degrees: image is upside down.
4= 180 degrees, mirrored: image has been flipped back-to-front and is upside down.
5= 90 degrees: image has been flipped back-to-front and is on its side.
6= 90 degrees, mirrored: image is on its side.
7= 270 degrees: image has been flipped back-to-front and is on its far side.
8= 270 degrees, mirrored: image is on its far side.

What I also found is that almost everything uses this data to automatically correct image orientation. I'm on Win11, and File Explorer, Word, etc... all use the data to show images properly oriented, as does Sigil.

Unfortunately, the epub I'm working on has a bunch of images that have non-"1" orientation values. The images all look OK as the book goes through Sigil, but when I view the book in (for example) Adobe Digital Editions, ADE ignores the orientation data and pictures show up turned in all directions. More critically, KDP also ignores orientation data.

Of course, since Sigil DOES adjust for orientation, there's no easy way to see which images need to be fixed.

So:
-Any ideas to help solve the immediate problem?
-Sigil Feature request: add ability to disable automatic image orientation (or ability to automatiaclly output reoriented images)

03-31-2024, 07:40 PM	#1
rcharbon Indie author Posts: 11 Karma: 10 Join Date: Oct 2011 Device: Kindle WiFi/iPhone	"Fix" EXIF orientation data in Sigil TIL that images can contain EXIF data to set orientation. The 8 EXIF orientation values are numbered 1 to 8: 1= 0 degrees: the correct orientation, no adjustment is required. 2= 0 degrees, mirrored: image has been flipped back-to-front. 3= 180 degrees: image is upside down. 4= 180 degrees, mirrored: image has been flipped back-to-front and is upside down. 5= 90 degrees: image has been flipped back-to-front and is on its side. 6= 90 degrees, mirrored: image is on its side. 7= 270 degrees: image has been flipped back-to-front and is on its far side. 8= 270 degrees, mirrored: image is on its far side. What I also found is that almost everything uses this data to automatically correct image orientation. I'm on Win11, and File Explorer, Word, etc... all use the data to show images properly oriented, as does Sigil. Unfortunately, the epub I'm working on has a bunch of images that have non-"1" orientation values. The images all look OK as the book goes through Sigil, but when I view the book in (for example) Adobe Digital Editions, ADE ignores the orientation data and pictures show up turned in all directions. More critically, KDP also ignores orientation data. Of course, since Sigil DOES adjust for orientation, there's no easy way to see which images need to be fixed. So: -Any ideas to help solve the immediate problem? -Sigil Feature request: add ability to disable automatic image orientation (or ability to automatiaclly output reoriented images)