plomlompom.com Git - misc/blob - bookmaker.py

   1 #!/usr/bin/env python3
   2 import pypdf
   3 import argparse
   4 import io
   5 from reportlab.lib.pagesizes import A4
   6 a4_width, a4_height = A4
   7
   8 parser = argparse.ArgumentParser(description="build print-ready book PDF")
   9 parser.add_argument("-i", "--input", dest="input_file", action="append", required=True, help="input PDF file")
  10 parser.add_argument("-o", "--output", dest="output_file", required=True, help="output PDF file")
  11 parser.add_argument("-p", "--pages", dest="page_range", action="append", help="page range, e.g., '3-end'")
  12 parser.add_argument("-c", "--crop", dest="crop_range", help="crops left, bottom, right, top – e.g., '10,10,10,10'")
  13 parser.add_argument("-n", "--nup4", dest="nup4", action='store_true', help="puts 4 input pages onto 1 output page")
  14 parser.add_argument("-a", "--analyze", dest="analyze", action="store_true", help="print lines identifying spine, page borders")
  15 parser.add_argument("-t", "--symmetry", dest="symmetry", action="store_true", help="alternate horizontal crops between odd and even pages")
  16 parser.add_argument("-r", "--rotate", dest="rotate", type=int, action="append", help="rotate page of number by 90° (usable multiple times on same page!)")
  17 parser.add_argument("-m", "--margin", type=float, default=4.3, help="print margin (default 4.3)")
  18 args = parser.parse_args()
  19
  20
  21 # select pages from input files
  22 pages_to_add = []
  23 opened_files = []
  24 for i, input_file in enumerate(args.input_file):
  25     file = open(input_file, 'rb')
  26     opened_files += [file]
  27     reader = pypdf.PdfReader(file)
  28     start_page = 0
  29     end_page = len(reader.pages)
  30     if args.page_range and len(args.page_range) > i:
  31         start, end = args.page_range[i].split('-')
  32         if not (len(start) == 0 or start == "start"):
  33             start_page = int(start) - 1
  34         if not (len(end) == 0 or end == "end"):
  35             end_page = int(end)
  36     for page_num in range(start_page, end_page):
  37         page = reader.pages[page_num]
  38         pages_to_add += [page]
  39         print("read in %s page number %d" % (input_file, page_num+1))
  40
  41 # rotate page canvas
  42 if args.rotate:
  43     for rotate in args.rotate:
  44         page = pages_to_add[rotate - 1]
  45         page.add_transformation(pypdf.Transformation().translate(tx=-a4_width/2, ty=-a4_height/2))
  46         page.add_transformation(pypdf.Transformation().rotate(-90))
  47         page.add_transformation(pypdf.Transformation().translate(tx=a4_width/2, ty=a4_height/2))
  48
  49 # normalize all pages to portrait A4
  50 for page in pages_to_add:
  51     if "/Rotate" in page:
  52         page.rotate(360 - page["/Rotate"])
  53     page.mediabox.left = 0
  54     page.mediabox.bottom = 0
  55     page.mediabox.top = a4_height
  56     page.mediabox.right = a4_width
  57     page.cropbox = page.mediabox
  58
  59 # determine page crop
  60 crop_left, crop_bottom, crop_right, crop_top = 0, 0, 0, 0
  61 if args.crop_range:
  62     crop_left, crop_bottom, crop_right, crop_top = [float(x) for x in  args.crop_range.split(',')]
  63 cropped_width  = a4_width - crop_left - crop_right
  64 cropped_height = a4_height - crop_bottom - crop_top
  65 zoom = 1
  66 if args.crop_range:
  67     zoom_horizontal = a4_width / (a4_width - crop_left - crop_right)
  68     zoom_vertical = a4_height / (a4_height - crop_bottom - crop_top)
  69     if (zoom_horizontal > 1 and zoom_vertical < 1) or (zoom_horizontal < 1 and zoom_vertical > 1):
  70         print("Error: opposing zooms.")
  71         exit(1)
  72     elif zoom_horizontal + zoom_vertical > 2:
  73         zoom = min(zoom_horizontal, zoom_vertical)
  74     else:
  75         zoom = max(zoom_horizontal, zoom_vertical)
  76
  77 writer = pypdf.PdfWriter()
  78 if not args.nup4:
  79     odd_page = True
  80     for page in pages_to_add:
  81         if args.symmetry and odd_page:
  82             page.add_transformation(pypdf.Transformation().translate(tx=-crop_right, ty=-crop_bottom))
  83         else:
  84             page.add_transformation(pypdf.Transformation().translate(tx=-crop_left, ty=-crop_bottom))
  85         page.add_transformation(pypdf.Transformation().scale(zoom, zoom))
  86         page.mediabox.right = cropped_width * zoom
  87         page.mediabox.top = cropped_height * zoom
  88         writer.add_page(page)
  89         odd_page = not odd_page
  90 else:
  91     n_pages_per_axis = 2
  92     points_per_mm = 2.83465
  93     printable_margin = args.margin * points_per_mm
  94     printable_scale = (a4_width - 2*printable_margin)/a4_width
  95     spine_limit = 10 * points_per_mm
  96     half_width = a4_width / n_pages_per_axis
  97     half_height = a4_height / n_pages_per_axis
  98     section_scale_factor = 1 / n_pages_per_axis
  99     spine_part_of_page = (spine_limit / half_width) / printable_scale
 100     bonus_shrink_factor = 1 - spine_part_of_page
 101     new_page_order = []
 102     eight_pack = []
 103     mod_to_8 = len(pages_to_add) % 8
 104     if mod_to_8 > 0:
 105         for _ in range(8 - mod_to_8):
 106             new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
 107             pages_to_add += [new_page]
 108     i = 0
 109     for page in pages_to_add:
 110         if i == 0:
 111             eight_pack = []
 112         eight_pack += [page]
 113         i += 1
 114         if i == 8:
 115             i = 0
 116             new_page_order += [eight_pack[3]]  # page front, upper left
 117             new_page_order += [eight_pack[0]]  # page front, upper right
 118             new_page_order += [eight_pack[7]]  # page front, lower left
 119             new_page_order += [eight_pack[4]]  # page front, lower right
 120             new_page_order += [eight_pack[1]]  # page back, upper left
 121             new_page_order += [eight_pack[2]]  # page back, upper right
 122             new_page_order += [eight_pack[5]]  # page back, lower left
 123             new_page_order += [eight_pack[6]]  # page back, lower right
 124     i = 0
 125     page_count = 0
 126     front_page = True
 127     for page in new_page_order:
 128         if i == 0:
 129             new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
 130
 131         # in-section transformations: align pages on top, left-hand pages to left, right-hand to right
 132         page.add_transformation(pypdf.Transformation().translate(ty=(a4_height / zoom - (a4_height - crop_top))))
 133         if i == 0 or i == 2:
 134             if args.symmetry:
 135                 page.add_transformation(pypdf.Transformation().translate(tx=-crop_left))
 136             else:
 137                 page.add_transformation(pypdf.Transformation().translate(tx=-crop_right))
 138         elif i == 1 or i == 3:
 139             if args.symmetry:
 140                 page.add_transformation(pypdf.Transformation().translate(tx=(a4_width / zoom - (a4_width - crop_left))))
 141             else:
 142                 page.add_transformation(pypdf.Transformation().translate(tx=(a4_width / zoom - (a4_width - crop_right))))
 143         page.add_transformation(pypdf.Transformation().scale(zoom * bonus_shrink_factor, zoom * bonus_shrink_factor))
 144         if i == 2 or i == 3:
 145             page.add_transformation(pypdf.Transformation().translate(ty=-2*printable_margin/printable_scale))
 146
 147         # outer section transformations
 148         page.add_transformation(pypdf.Transformation().translate(ty=(1-bonus_shrink_factor)*a4_height))
 149         if i == 0 or i == 1:
 150             y_section = a4_height
 151             page.mediabox.bottom = half_height
 152             page.mediabox.top    = a4_height
 153         if i == 2 or i == 3:
 154             y_section = 0
 155             page.mediabox.bottom = 0
 156             page.mediabox.top  =   half_height
 157         if i == 0 or i == 2:
 158             x_section = 0
 159             page.mediabox.left   = 0
 160             page.mediabox.right  = half_width
 161         if i == 1 or i == 3:
 162             page.add_transformation(pypdf.Transformation().translate(tx=(1-bonus_shrink_factor)*a4_width))
 163             x_section = a4_width
 164             page.mediabox.left   = half_width
 165             page.mediabox.right  = a4_width
 166         page.add_transformation(pypdf.Transformation().translate(tx=x_section, ty=y_section))
 167         page.add_transformation(pypdf.Transformation().scale(section_scale_factor, section_scale_factor))
 168         new_page.merge_page(page)
 169         page_count += 1
 170         print("merged page number", page_count)
 171         i += 1
 172         if i > 3:
 173             from reportlab.pdfgen import canvas
 174             if args.analyze:
 175                 # borders
 176                 packet = io.BytesIO()
 177                 c = canvas.Canvas(packet, pagesize=A4)
 178                 c.setLineWidth(0.1)
 179                 c.line(0, a4_height, a4_width, a4_height)
 180                 c.line(0, half_height, a4_width, half_height)
 181                 c.line(0, 0, a4_width, 0)
 182                 c.line(0, a4_height, 0, 0)
 183                 c.line(half_width, a4_height, half_width, 0)
 184                 c.line(a4_width, a4_height, a4_width, 0)
 185                 c.save()
 186                 new_pdf = pypdf.PdfReader(packet)
 187                 new_page.merge_page(new_pdf.pages[0])
 188             printable_offset_x = printable_margin
 189             printable_offset_y = printable_margin * a4_height / a4_width
 190             new_page.add_transformation(pypdf.Transformation().scale(printable_scale, printable_scale))
 191             new_page.add_transformation(pypdf.Transformation().translate(tx=printable_offset_x, ty=printable_offset_y))
 192             x_left_spine_limit = half_width * bonus_shrink_factor
 193             x_right_spine_limit = a4_width - x_left_spine_limit
 194             if args.analyze or front_page:
 195                 packet = io.BytesIO()
 196                 c = canvas.Canvas(packet, pagesize=A4)
 197             if args.analyze:
 198                 # # spine lines
 199                 c.setLineWidth(0.1)
 200                 c.line(x_left_spine_limit, a4_height, x_left_spine_limit, 0)
 201                 c.line(x_right_spine_limit, a4_height, x_right_spine_limit, 0)
 202             if front_page:
 203                 c.setLineWidth(0.2)
 204                 cut_depth = 19.5 * points_per_mm
 205                 cut_width = 10.5 * points_per_mm
 206                 middle_point_depth = 4 * points_per_mm
 207
 208                 start_up_left_left_x = x_left_spine_limit - 0.5 * cut_width
 209                 start_up_left_right_x = x_left_spine_limit + 0.5 * cut_width
 210                 middle_point_up_left_y = half_height + middle_point_depth
 211                 end_point_up_left_y = half_height + cut_depth
 212                 c.line(start_up_left_right_x, half_height, x_left_spine_limit, end_point_up_left_y)
 213                 c.line(x_left_spine_limit, end_point_up_left_y, x_left_spine_limit, middle_point_up_left_y)
 214                 c.line(x_left_spine_limit, middle_point_up_left_y, start_up_left_left_x, half_height)
 215
 216                 start_down_right_left_x = x_right_spine_limit - 0.5 * cut_width
 217                 start_down_right_right_x = x_right_spine_limit + 0.5 * cut_width
 218                 middle_point_down_right_y = half_height - middle_point_depth
 219                 end_point_down_right_y = half_height - cut_depth
 220                 c.line(start_down_right_left_x, half_height, x_right_spine_limit, end_point_down_right_y)
 221                 c.line(x_right_spine_limit, end_point_down_right_y, x_right_spine_limit, middle_point_down_right_y)
 222                 c.line(x_right_spine_limit, middle_point_down_right_y, start_down_right_right_x, half_height)
 223
 224             if args.analyze or front_page:
 225                 c.save()
 226                 new_pdf = pypdf.PdfReader(packet)
 227                 new_page.merge_page(new_pdf.pages[0])
 228             writer.add_page(new_page)
 229             i = 0
 230             front_page = not front_page
 231 for file in opened_files:
 232     file.close()
 233
 234 with open(args.output_file, 'wb') as output_file:
 235     writer.write(output_file)