cannot rotate pages of some PDF

[shin1007]

Problem description.
In some pages of PDFs, their rotation matrix and derotation matrix are like
Matrix(1.0, 0.0, 0.0, 1.0, 0.0, 0.0)
Matrix(1.0, -0.0, -0.0, 1.0, 0.0, 0.0)
and we cannot rotate these pages properly.

Solution I'd like
adding new methods like set_rotation_matrix and set_derotation_matrix.
which set desirable matrixes and thus we can rotate pages with improper rotation matrix.

Alternatives I've considered
names of the methods can be different.

[JorjMcKie]

I don't understand:
Page (de-) rotation matrix is computed automatically by inspecting a page's rotation.
Changing / setting page rotation via page.set_rotation(degree) will also change those matrices.

[JorjMcKie]

Look at this:

>>> for degree in (0, 90, 180, 270):
	page.set_rotation(degree)
	print("de-rot:", page.derotation_matrix)
	print("   rot:", page.rotation_matrix)

	
de-rot: Matrix(1.0, -0.0, -0.0, 1.0, 0.0, 0.0)
   rot: Matrix(1.0, 0.0, 0.0, 1.0, 0.0, 0.0)
de-rot: Matrix(0.0, -1.0, 1.0, 0.0, -0.0, 842.0)
   rot: Matrix(0.0, 1.0, -1.0, 0.0, 842.0, 0.0)
de-rot: Matrix(-1.0, -0.0, -0.0, -1.0, 595.0, 842.0)
   rot: Matrix(-1.0, 0.0, 0.0, -1.0, 595.0, 842.0)
de-rot: Matrix(0.0, 1.0, -1.0, 0.0, 595.0, -0.0)
   rot: Matrix(0.0, -1.0, 1.0, 0.0, 0.0, 595.0)
>>>  

[shin1007]

I'll check my PDF again. thanks

[shin1007]

Thanks to your advice, I've understood it's not related to rotation matrix.
however, I'm still facing a problem with rotation.
I would be pretty happy if you kindly spare some time for solving this problem.

I'm doing a kind of 2-ups and it works for some pdf and does not work for some others.
I need to rotate the page if its paper size is a4 portrait before attaching to a3 paper left / right.
code below sometimes does not rotate as i expect.
it shows just left part of the original page(a4-landscape).

it looks working if i simply overwrite src_pdf.
but still having problem when i try to 2-up again.

are there any solutions you come up with?
TIA

a3_w, a3_h = fitz.paper_size("a3-l")
rect_a3_left = fitz.Rect(0, 0, a3_w/2, a3_h)
rect_a3_right = fitz.Rect(a3_w/2, 0, a3_w, a3_h)

a4_w, a4_h = fitz.paper_size("a4")
rect_a4_portrait = fitz.Rect(0, 0, a4_w, a4_h)
rect_a4_landscape = fitz.Rect(0, 0, a4_h, a4_w)

page = new_pdf.new_page(-1, width = a3_w, height = a3_h)

if paper_size == 'a4_landscape':
    print(paper_size_of(src_pdf[i]))
    print(src_pdf[i].rotation)
    print(src_pdf[i].rotation_matrix)
    print(src_pdf[i].derotation_matrix)
    if src_pdf[i].rotation == 0:
        src_pdf[i].set_rotation(270)
    else:
        src_pdf[i].set_rotation(src_pdf[i].rotation - 90)
    print(paper_size_of(src_pdf[i]))
    print(src_pdf[i].rotation)
    print(src_pdf[i].rotation_matrix)
    print(src_pdf[i].derotation_matrix)
    page.show_pdf_page(rect_a3_left, src_pdf, i)

[JorjMcKie]

The simplest way is probably this: set the source page's rotation to 0 before inserting it.

src = fitz.open("source.pdf")
rect = fitz.paper_rect("a3-l")
w, h = fitz.paper_size("a3-l")
rl = fitz.paper_rect("a4")  # equal left side of A3 landscape
rr = rl + (rl.width, 0, rl.width, 0)  # the right side
doc = fitz.open()
for srcpage in src:
	srcpage.set_rotation(0)
	if not srcpage.number % 2:  # make new output page on even input number
		page = doc.new_page(width=w, height=h)
		page.show_pdf_page(rl, src, srcpage.number)
	else:
		page.show_pdf_page(rr, src, srcpage.number)

[shin1007]

Thank you for your quick reply.

I'm sorry but I made a mistake describing my project.
I am trying to rotate A4 LANDSCAPE page.(not portrait)

In some PDFs i can rotate it properly but not for others.

I'm doing a kind of 2-ups and it works for some pdf and does not work for some others.
I need to rotate the page if its paper size is a4 portrait before attaching to a3 paper left / right.
code below sometimes does not rotate as i expect.
it shows just left part of the original page(a4-landscape).

[JorjMcKie]

If a page is landscape, then page.rect.width > page.rect.height and page.rotation == 0. If so, then do page.set_rotation(90) or -90 depending on how you want to see the output.

[shin1007]

I seem not making myself clear.
I did the page.set_rotation and it seems not working properly

1. original PDF, a4 landscape
   2x

2. what i get (page.set_rotation(270) , then 2-up)
   

3. what i get (page.set_rotation(270), NO 2-up)
   2x

4. what i get (2-up number 3 above)
   

[JorjMcKie]

Please send me that file - we are talking past each other.

[shin1007]

here is my pdf.
thank you for your kind support.

https://drive.google.com/open?id=1OwXxOZe_zdSNeMUSs2kipRXKqYD4BkXv&authuser=shin1007%40gmail.com&usp=drive_fs

[JorjMcKie]

Here is the script that does work for both those files.
Explanation:
The "rotate" argument in show_pdf_page can only work in a foreseeable way, if the source page is not rotated. If it is rotated, use my code snippet from a previous post.

import fitz

doc1 = fitz.open("syousa2.pdf")
doc2 = fitz.open("syousa_2up.pdf")

newpdf = fitz.open()
w, h = fitz.paper_size("a3-l")

# left and right A4 rectangles:
rl = fitz.paper_rect("a4")
rr = rl + (rl.width, 0, rl.width, 0)

for page in doc1:  # loop through source pages
    if not page.number % 2:  # on even pages create the output A3 page
        rect = rl
        newpage = newpdf.new_page(width=w, height=h)
    else:
        rect = rr

    if page.rotation == 0 and page.rect.width > page.rect.height:
        rot = 90
    else:
        rot = 0

    newpage.show_pdf_page(rect, doc1, page.number, rotate=rot)

newpdf.ez_save(doc1.name + "-up.pdf")
newpdf.close()

newpdf = fitz.open()
for page in doc2:
    if not page.number % 2:
        rect = rl
        newpage = newpdf.new_page(width=w, height=h)
    else:
        rect = rr

    if page.rotation == 0 and page.rect.width > page.rect.height:
        rot = 90
    else:
        rot = 0

    newpage.show_pdf_page(rect, doc2, page.number, rotate=rot)

newpdf.ez_save(doc2.name + "-up.pdf")

[shin1007]

Thank you soooo much, my hero.
I'll use your snippet!!!!