How to merge two landscape pdf pages using pyPdf

Question

I'm having trouble merging two PDF files with pyPdf. When I run the following code the the watermark (page1) looks fine, but the page2 has been rotated 90 degrees clockwise.

Any ideas what's going on?

from pyPdf import PdfFileWriter, PdfFileReader

# PDF1: A4 Landscape page created in photoshop using PdfCreator, 
input1 = PdfFileReader(file("base.pdf", "rb"))
page1 = input1.getPage(0)

# PDF2: A4 Landscape page, text only, created using Pisa (www.xhtml2pdf.com)
input2 = PdfFileReader(file("text.pdf", "rb"))
page2 = input2.getPage(0)

# Merge
page1.mergePage(page2)

# Output
output = PdfFileWriter()
output.addPage(page1)
outputStream = file("output.pdf", "wb")
output.write(outputStream)
outputStream.close()

Answer 1

I found a solution. My code was fine - I just had to change how I generated the original PDF files.

Instead of creating the PDF using PdfCreator & Photoshop, I copy and pasted my photoshop image into MS Word 2007, and then used it's export feature to create the PDF file for page1. It now works great!

So, PdfCreator must producing PDF files that are not compatible with pyPdf.

Answer 2

You can transform the page while you're merging it into another page. I defined this function to rotate the page around a point while being merged:

def mergeRotateAroundPointPage(page, page2, rotation, tx, ty):
    translation = [[1, 0, 0],
                   [0, 1, 0],
                   [-tx,-ty,1]]
    rotation = math.radians(rotation)
    rotating = [[math.cos(rotation), math.sin(rotation),0],
                [-math.sin(rotation),math.cos(rotation), 0],
                [0,                  0,                  1]]
    rtranslation = [[1, 0, 0],
                   [0, 1, 0],
                   [tx,ty,1]]
    ctm = utils.matrixMultiply(translation, rotating)
    ctm = utils.matrixMultiply(ctm, rtranslation)

    return page.mergeTransformedPage(page2, [ctm[0][0], ctm[0][1],
                                             ctm[1][0], ctm[1][1],
                                             ctm[2][0], ctm[2][1]])

Then you call it like this:

mergeRotateAroundPointPage(page1, page2, 
                page1.get('/Rotate') or 0, 
                page2.mediaBox.getWidth()/2, page2.mediaBox.getWidth()/2)

Answer 3

Since you're using pyPdf, this should do the trick for rotating pages:

output.addPage(input1.getPage(1).rotateClockwise(90))

Answer 4

I would like to add that I used Photoshop to save the PDF but as version 1.4 compatible. This made a huge PDF file but it worked.

So it is pyPDF not reading it right.

Answer 5

You can make use of the rotateClockwise or rotataeCounterClockwise function in the page object.

page2 = input2.getPage(0).rotateCounterClockwise(90)