DOC: Add Scripts/booklet.py (#469)

Scripts/booklet.py

@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+
+"""
+    Layout the pages from a PDF file to print a booklet or brochure.
+
+    The resulting media size is twice the size of the first page
+    of the source document. If you print the resulting PDF in duplex
+    (short edge), you get a center fold brochure that you can staple
+    together and read as a booklet.
+"""
+
+from __future__ import division, print_function
+import PyPDF2
+import argparse
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument('input', type=argparse.FileType('rb'))
+    parser.add_argument('output')
+    args = parser.parse_args()
+
+    reader = PyPDF2.PdfFileReader(args.input)
+    numPages = reader.getNumPages()
+    print('Pages in file:', numPages)
+
+    pagesPerSheet = 4
+    virtualPages = (numPages + pagesPerSheet - 1) // pagesPerSheet * pagesPerSheet
+
+    firstPage = reader.getPage(0)
+    mb = firstPage.mediaBox
+    pageWidth = 2 * mb.getWidth()
+    pageHeight = mb.getHeight()
+    print('Medium size:', '{}x{}'.format(pageWidth, pageHeight))
+
+    writer = PyPDF2.PdfFileWriter()
+
+    def scale(page):
+        return min(mb.getWidth() / page.mediaBox.getWidth(), mb.getHeight() / page.mediaBox.getHeight())
+
+    def mergePage(dst, src, xOffset):
+        pageScale = scale(src)
+        print('scaling by', pageScale)
+        dx = (mb.getWidth() - pageScale * src.mediaBox.getWidth()) / 2
+        dy = (mb.getHeight() - pageScale * src.mediaBox.getHeight()) / 2
+        dst.mergeScaledTranslatedPage(src, scale(src), xOffset + dx, dy)
+
+    def mergePageByNumber(dstPage, pageNumber, xOffset):
+        if pageNumber >= numPages:
+            return
+        print('merging page', pageNumber, 'with offset', xOffset)
+        page = reader.getPage(pageNumber)
+        mergePage(dstPage, page, xOffset)
+
+    for i in range(virtualPages // 2):
+        page = writer.addBlankPage(width=pageWidth, height=pageHeight)
+        offsets = [0, pageWidth // 2]
+        if i % 2 == 0:
+            offsets.reverse()
+        mergePageByNumber(page, i, offsets[0])
+        mergePageByNumber(page, virtualPages - i - 1, offsets[1])
+
+    writer.write(open(args.output, 'wb'))
+
+
+if __name__ == '__main__':
+    main()