Changing the header produces missalignment when processing the questions

Added by Adin Ramirez about 4 years ago

Hi,

I just discovered that changing the header on the tests produces miss-alignments on subsequent pages of the tests. I just noticed the error like 2 months or so ago. First, I thought it was due to changing the sizes or resolutions on printing and scanning, but further tests indicate that that is not the problem.

I'm attaching a sample test so you can further see the problem. My guess is that the size of the header is influencing the detection on the next pages.

The layout, when inspected after creating the test, shows no errors on the pages (see attachment). However, once the questions are processed there are missalignment errors that seem to correlate with the size of the header (just from visual cues). Note that I tested this by using the created pdf, so there are no scanning artifacts on the processed tests. The problems get worse when you scan the tests.

I'm using version 1.4.0~beta1+git-2018-05-15 on an Ubuntu 18.04. Please let me know if I can help debugging the problem further.

missalignment-test.tex - Sample (1.2 kB)

layout.png - Layout sample (50.2 kB)

processed.png - Same questions after been processed (80.9 kB)


Replies (10)

RE: Changing the header produces missalignment when processing the questions - Added by Alexis Bienvenüe about 4 years ago

Where does the processed.png picture come from?
Can you show us a step-by-step procedure to reproduce the problem?

RE: Changing the header produces missalignment when processing the questions - Added by Adin Ramirez about 4 years ago

It is a screenshot from the interface when you are inspecting the processed layouts (Manual inspection on Data Capture tab).

The steps to reproduce are as follows:

- Create new project from file
- Select missalignment-test.tex
- On preparation create 1 file
- Click "update documents"
- Wait for the documents to be created, and then do "layout detection"
- On the "Data capture" tab, select automatic and navigate to your project and select "DOC-sujet.pdf"
- After the process is done, click on "Manual"
- Change the view from "Original" to "Scan"
- Select pages different from the first and you will see the miss alignment on the detected boxes

RE: Changing the header produces missalignment when processing the questions - Added by Alexis Bienvenüe about 4 years ago

Thanks.
The four corner circles must be at the exact same position on all pages on the subject for AMC to work. AMC should warn you if this is not the case, but here this warning is broken: I have to fix this.

RE: Changing the header produces missalignment when processing the questions - Added by Adin Ramirez about 4 years ago

Yea, I understand.

But the problem is that since it is the PDF shouldn't the dots be on the same position?

Also, the header is not moving them, is it? If you see the first page is detected correctly, but the next ones aren't.

RE: Changing the header produces missalignment when processing the questions - Added by Alexis Bienvenüe about 4 years ago

On your PDF, the bottom dots are not at the same position on pages 1 and 2 (on page 2, they are lower).

RE: Changing the header produces missalignment when processing the questions - Added by Adin Ramirez about 4 years ago

Do you know what may be producing that?

As you can see I'm only adding the fancyhdr. Adnd that didn't create problems before, but now it is.

Any ideas?

RE: Changing the header produces missalignment when processing the questions - Added by Adin Ramirez about 4 years ago

Also, I'm not sure if that is related, but the detected layout at the per-processing detects all the marks correctly.

It is only on the scan that it produces error.

RE: Changing the header produces missalignment when processing the questions - Added by Alexis Bienvenüe about 4 years ago

Do you know what may be producing that?

No but this is the source of your problem, and has to be fixed from your source file.

RE: Changing the header produces missalignment when processing the questions - Added by Alexis Bienvenüe about 4 years ago

It seems to work with \geometry{headheight=3cm} in the preamble (the default value 2cm is not enough for your header).

RE: Changing the header produces missalignment when processing the questions - Added by Adin Ramirez about 4 years ago

Thanks for the help.

Indeed, updating the headheight influences the footer misplacement.

I will try to further investigate what is happening. It shouldn't be a problem whether the margins are updated.

For now, updating the headheight and the top margin fixes the misalignments.

(1-10/10)