An example page, before horizontal trim
after horizontal trim
with auto split pages, notice the specific alignment of the blue lines, in the crease of the page, and to the right of the book cover
shown in deskew, notice the edges of the image are now too far to the left, revealing past the crease of the pages, and chopping off in the margin of the right side.
In some cases, the misalignment is so bad that it chops content in the deskew view even though the blue lines are in the correct locations on the split pages screen. Sometimes if I change the trim value for the horizontal trim on the left side, the problem goes away, but often it doesn't.
An example page, before horizontal trim
after horizontal trim
with auto split pages, notice the specific alignment of the blue lines, in the crease of the page, and to the right of the book cover
shown in deskew, notice the edges of the image are now too far to the left, revealing past the crease of the pages, and chopping off in the margin of the right side.
In some cases, the misalignment is so bad that it chops content in the deskew view even though the blue lines are in the correct locations on the split pages screen. Sometimes if I change the trim value for the horizontal trim on the left side, the problem goes away, but often it doesn't.