The "Deskew Pages" function does not work correctly

[Jensen Head]

In most cases, the "Deskew Pages" feature works correctly. But sometimes there are pages on which, for unknown reasons, the function refuses to work. Example — https://drive.google.com/file/d/13WMRypHEC-f90HWAYFv8Q-_VXLeCXGoh/view (after activating the function, the page remains unchanged, with a significant skew)

PDF-XChange Editor Plus 10.2.1, build 385 (Enhanced OCR)
Microsoft Windows 10.0.19045.4239

[Daniel - PDF-XChange]

Hello, Jensen Head

Thank you for the file, It seems that this has already been improved in the current version of our internal nightly build, so you can look forward to this being fixed (at least for this document) in the next release.
If you have other samples which have the same issue, please do not hesitate to send some along. I can double check, and forward any which still show the same problem, to the Dev team for resolution.

Kind regards,

[Jensen Head]

If you have other samples which have the same issue, please do not hesitate to send some along.

Original:

2024-12-11_23-36-32.png

Deskewed:

2024-12-11_23-49-54.png

PDF-XChange Editor Plus 10.4.3, build 391 (Enhanced OCR)

[Daniel - PDF-XChange]

Hello, Jensen Head

Thank you for the report, The current nightly once again seems to have less of an issue but it does appear to be slightly "overskewing" the image still.

Unfortunately in this documents case, the main item we use to determine skew (lines of text) are curved due to a poor quality scan. We do now offer a 2D perspective correction function (As part of "enhance scanned pages"), but for some reason that also does not want to cooperate with this file in my tests, so I have forwarded it to the Dev team, reporting both issues.

Hopefully we can find a way to offer this for you, but I should warn that it is, to some degree, expected for Deskew to struggle with pages that have "curved" text images like this one does.

Kind regards,

[Jensen Head]

Even though the entire content of the scanned page is skewed, the Deskew Pages function does not work because the dirty edge of the scanner glass is displayed at the top of the page, and the page alignment occurs according to it:
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Kreschenie_2.webp

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There is no convenient manual way to correct skew in the application yet.

[Daniel - PDF-XChange]

Hello, Jensen Head

I have passed this new sample along for review by the dev team. Hopefully we can find a working solution to mitigate this issue.

Kind regards,

[Jensen Head]

Another example of a page that doesn't respond to this feature.

[Daniel - PDF-XChange]

Hello, Jensen Head

Thank you for the example, I have passed it up to the dev team for review. I also tried using enhance scans, and that similarly failed to make any changes. So it has been noted to the team.

Kind regards,

[mCHSNUg5Pz8cPap]

If you are looking at making changes to deskew, then I would recommend consulting this thread and seeing if something can be done to improve the image quality (I show in the following linked post that at least one free online vendor is capable of providing clear, relatively small deskewed files so it's certainly possible).
viewtopic.php?p=193134#p193134

[Dimitar - PDF-XChange]

Thanks for the input, mCHSNUg5Pz8cPap.

[Jensen Head]

Another example of a page that doesn't respond to this feature.

The Deskew Pages function does not work correctly (2025-11-25).pdf

[Sean - PDF-XChange]

Thanks Jensen Head - let's wait to see what the developers say.

Kind regards,

[Jensen Head]

[url=https://drive.google.com/file/d/1gSQHA6hRZWKR8ZXjjUhg8jvFoRQ73t8g/view]The Deskew Pages function does not work correctly (2026-08-01).pdf[/url] (Google Drive, 172 KB)— deskew correction works when using “Deskew Page Content,” but does not work when using “Detect skew of page content” or “Fix content skew and incorrect page rotation.” This is unexpected behavior, forcing a user processing at least scanned pages to prefer the standalone page deskew feature rather than running a batch job that includes recognition and deskew.

(The amount of skew in the example given is approximately 0.3°.)

[Daniel - PDF-XChange]

Hello, Jensen Head

Before we begin, I have used the "recolor pages" function to remove the background color (converting the page to B/W), as the original contrast was too low to visualize in my example below. All of the items mentioned below have been tested in the original file, the coloration change here is purely for example sake.

This document is not skewed, but warped. If you use guides at the top of the page and compare to the middle and bottom of the page, you will see the you have two competing skew directions - at the top, it skews upwards, while at the bottom text skews downwards.

image.png

image(1).png

The Deskew pages function is not intended to handle page warping at this time, but it is something we are looking into in the future.
For the time being, if you wish to generate more "inline/straight" text lines, you will want to use the Enhanced "OCR pages" function, to generate replacement test in place of the image content.

image(2).png

image(3).png

As you can see, this text is generated without the aforementioned skew, in the correct locations.

From my tests, the "fix content skew" option in the OCR page dialogue is working, it is simply applying a smaller deskew action than what the "deskew pages" action performs alone - in large part due to the conflicting skews from the mentioned warping.
The goal of this tool is to ensure that the OCR action can capture the text properly. When there is a conflict in rotation values like this, the results will not always match the deskew pages function.

Kind regards,

[Jensen Head]

Daniel, thanks for the detailed and well-illustrated explanation! I, and probably some other users, will be eagerly watching the releases for new features to fix page warping!

[Sean - PDF-XChange]