How do I properly insert text into a rotating page？

[yang-521]

I was trying to make a double-layer PDF, but I couldn't insert text correctly when I encountered a rotated page
The coordinates returned by the page OCR result are the rotated view coordinates, and when I insert text on the page with these coordinates, the result is where it was before the rotation
How to put it correctly？

[JorjMcKie]

Please provide enough information to reproduce.

[JorjMcKie]

In the general case, you need the page's rotation matrix and the rotation value. Then, for every insertion point origin do page.insert_text(origin * page.derotation_matrix, "text", rotate=angle).

[yang-521]

Thank you very much! I used page.derotation_matrix to recalculate the coordinates and insert, and got what I wanted

[agademic]

Sorry for reopening the post, but I encountered the same issue as OP and was not able to solve it so far.

I have a scanned PDF (images only; rotation 270) and a text layer PDF (coming from tesseract, rotation 0). I want to merge these two PDFs into a single PDF but every attempt ended up in one of the PDFs incorrectly rotated.

I tried page.set_rotation() for both image page and text page before merging them into a new page, I tried Matrix.prerotate() as well to no avail.

This is my code:

import fitz
# prepare original page
original = fitz.open("image_pdf.pdf")
original_page = original[0]

text_doc = fitz.open("text_page.pdf")
text_page = text_doc[0]

page_width = original_page.rect.width
page_height = original_page.rect.height
rotation = original_page.rotation
rotation_text = text_page.rotation
print(f"Rotation Original: {rotation}")
print(f"Rotation Text: {rotation_text}")

new_doc = fitz.open()

# # Handle rotation
if rotation in [90, 270]:
    # flip width and height
    page_width, page_height = page_height, page_width
new_page = new_doc.new_page(width=original_page.rect.height, height=original_page.rect.width)
# calculate scaling factors
scale_x = page_width / original_page.rect.width
scale_y = page_height / original_page.rect.height
# Adjust for rotation
if rotation != 0:
    # rotate the new page back to match the original page
    new_page.set_rotation(rotation)

# Create a transformation matrix for scaling
transform = fitz.Matrix(scale_x, scale_y)

# Render the text page onto the original page
new_page.show_pdf_page(new_page.rect, original, 0, matrix=transform)

new_page.show_pdf_page(new_page.rect, text_doc, 0, matrix=transform)

# Save the new document as a PDF
new_doc.save("image_page.pdf")

As I understood from your conversation above, we could use page.insert_text(origin * page.derotation_matrix, "text", rotate=angle) to insert text. Would this work in my approach as well?

I would appreciate so much if you could point me to the right direction.

[yang-521]

I used page.derotation_matrix to calculate the rotated coordinates

[JorjMcKie]

The simplest way to achieve what you want is to forget all about rotation by removing any source page rotation via src_page.remove_rotation().
This will set the rotation to 0 without changing the visual appearance.

This page method can always be executed - even when the rotation already is 0.

[agademic]

Thank you for the suggestion!