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", help="rotate page of number by 90°")
  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     page = pages_to_add[int(args.rotate) - 1]
  44     page.add_transformation(pypdf.Transformation().translate(tx=-a4_width/2, ty=-a4_height/2))
  45     page.add_transformation(pypdf.Transformation().rotate(-90))
  46     page.add_transformation(pypdf.Transformation().translate(tx=a4_width/2, ty=a4_height/2))
  47
  48 # normalize all pages to portrait A4
  49 for page in pages_to_add:
  50     if "/Rotate" in page:
  51         page.rotate(360 - page["/Rotate"])
  52     page.mediabox.left = 0
  53     page.mediabox.bottom = 0
  54     page.mediabox.top = a4_height
  55     page.mediabox.right = a4_width
  56     page.cropbox = page.mediabox
  57
  58 # determine page crop
  59 crop_left, crop_bottom, crop_right, crop_top = 0, 0, 0, 0
  60 if args.crop_range:
  61     crop_left, crop_bottom, crop_right, crop_top = [float(x) for x in  args.crop_range.split(',')]
  62 cropped_width  = a4_width - crop_left - crop_right
  63 cropped_height = a4_height - crop_bottom - crop_top
  64 zoom = 1
  65 if args.crop_range:
  66     zoom_horizontal = a4_width / (a4_width - crop_left - crop_right)
  67     zoom_vertical = a4_height / (a4_height - crop_bottom - crop_top)
  68     if (zoom_horizontal > 1 and zoom_vertical < 1) or (zoom_horizontal < 1 and zoom_vertical > 1):
  69         print("Error: opposing zooms.")
  70         exit(1)
  71     elif zoom_horizontal + zoom_vertical > 2:
  72         zoom = min(zoom_horizontal, zoom_vertical)
  73     else:
  74         zoom = max(zoom_horizontal, zoom_vertical)
  75
  76 writer = pypdf.PdfWriter()
  77 if not args.nup4:
  78     odd_page = True
  79     for page in pages_to_add:
  80         if args.symmetry and odd_page:
  81             page.add_transformation(pypdf.Transformation().translate(tx=-crop_right, ty=-crop_bottom))
  82         else:
  83             page.add_transformation(pypdf.Transformation().translate(tx=-crop_left, ty=-crop_bottom))
  84         page.add_transformation(pypdf.Transformation().scale(zoom, zoom))
  85         page.mediabox.right = cropped_width * zoom
  86         page.mediabox.top = cropped_height * zoom
  87         writer.add_page(page)
  88         odd_page = not odd_page
  89 else:
  90     n_pages_per_axis = 2
  91     points_per_mm = 2.83465
  92     printable_margin = args.margin * points_per_mm
  93     printable_scale = (a4_width - 2*printable_margin)/a4_width
  94     spine_limit = 10 * points_per_mm
  95     half_width = a4_width / n_pages_per_axis
  96     half_height = a4_height / n_pages_per_axis
  97     section_scale_factor = 1 / n_pages_per_axis
  98     spine_part_of_page = (spine_limit / half_width) / printable_scale
  99     bonus_shrink_factor = 1 - spine_part_of_page
 100     new_page_order = []
 101     eight_pack = []
 102     mod_to_8 = len(pages_to_add) % 8
 103     if mod_to_8 > 0:
 104         for _ in range(8 - mod_to_8):
 105             new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
 106             pages_to_add += [new_page]
 107     i = 0
 108     for page in pages_to_add:
 109         if i == 0:
 110             eight_pack = []
 111         eight_pack += [page]
 112         i += 1
 113         if i == 8:
 114             i = 0
 115             new_page_order += [eight_pack[3]]  # page front, upper left
 116             new_page_order += [eight_pack[0]]  # page front, upper right
 117             new_page_order += [eight_pack[7]]  # page front, lower left
 118             new_page_order += [eight_pack[4]]  # page front, lower right
 119             new_page_order += [eight_pack[1]]  # page back, upper left
 120             new_page_order += [eight_pack[2]]  # page back, upper right
 121             new_page_order += [eight_pack[5]]  # page back, lower left
 122             new_page_order += [eight_pack[6]]  # page back, lower right
 123     i = 0
 124     page_count = 0
 125     front_page = True
 126     for page in new_page_order:
 127         if i == 0:
 128             new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
 129
 130         # in-section transformations: align pages on top, left-hand pages to left, right-hand to right
 131         page.add_transformation(pypdf.Transformation().translate(ty=(a4_height / zoom - (a4_height - crop_top))))
 132         if i == 0 or i == 2:
 133             if args.symmetry:
 134                 page.add_transformation(pypdf.Transformation().translate(tx=-crop_left))
 135             else:
 136                 page.add_transformation(pypdf.Transformation().translate(tx=-crop_right))
 137         elif i == 1 or i == 3:
 138             if args.symmetry:
 139                 page.add_transformation(pypdf.Transformation().translate(tx=(a4_width / zoom - (a4_width - crop_left))))
 140             else:
 141                 page.add_transformation(pypdf.Transformation().translate(tx=(a4_width / zoom - (a4_width - crop_right))))
 142         page.add_transformation(pypdf.Transformation().scale(zoom * bonus_shrink_factor, zoom * bonus_shrink_factor))
 143         if i == 2 or i == 3:
 144             page.add_transformation(pypdf.Transformation().translate(ty=-2*printable_margin/printable_scale))
 145
 146         # outer section transformations
 147         page.add_transformation(pypdf.Transformation().translate(ty=(1-bonus_shrink_factor)*a4_height))
 148         if i == 0 or i == 1:
 149             y_section = a4_height
 150             page.mediabox.bottom = half_height
 151             page.mediabox.top    = a4_height
 152         if i == 2 or i == 3:
 153             y_section = 0
 154             page.mediabox.bottom = 0
 155             page.mediabox.top  =   half_height
 156         if i == 0 or i == 2:
 157             x_section = 0
 158             page.mediabox.left   = 0
 159             page.mediabox.right  = half_width
 160         if i == 1 or i == 3:
 161             page.add_transformation(pypdf.Transformation().translate(tx=(1-bonus_shrink_factor)*a4_width))
 162             x_section = a4_width
 163             page.mediabox.left   = half_width
 164             page.mediabox.right  = a4_width
 165         page.add_transformation(pypdf.Transformation().translate(tx=x_section, ty=y_section))
 166         page.add_transformation(pypdf.Transformation().scale(section_scale_factor, section_scale_factor))
 167         new_page.merge_page(page)
 168         page_count += 1
 169         print("merged page number", page_count)
 170         i += 1
 171         if i > 3:
 172             from reportlab.pdfgen import canvas
 173             if args.analyze:
 174                 # borders
 175                 packet = io.BytesIO()
 176                 c = canvas.Canvas(packet, pagesize=A4)
 177                 c.setLineWidth(0.1)
 178                 c.line(0, a4_height, a4_width, a4_height)
 179                 c.line(0, half_height, a4_width, half_height)
 180                 c.line(0, 0, a4_width, 0)
 181                 c.line(0, a4_height, 0, 0)
 182                 c.line(half_width, a4_height, half_width, 0)
 183                 c.line(a4_width, a4_height, a4_width, 0)
 184                 c.save()
 185                 new_pdf = pypdf.PdfReader(packet)
 186                 new_page.merge_page(new_pdf.pages[0])
 187             printable_offset_x = printable_margin
 188             printable_offset_y = printable_margin * a4_height / a4_width
 189             new_page.add_transformation(pypdf.Transformation().scale(printable_scale, printable_scale))
 190             new_page.add_transformation(pypdf.Transformation().translate(tx=printable_offset_x, ty=printable_offset_y))
 191             x_left_spine_limit = half_width * bonus_shrink_factor
 192             x_right_spine_limit = a4_width - x_left_spine_limit
 193             if args.analyze or front_page:
 194                 packet = io.BytesIO()
 195                 c = canvas.Canvas(packet, pagesize=A4)
 196             if args.analyze:
 197                 # # spine lines
 198                 c.setLineWidth(0.1)
 199                 c.line(x_left_spine_limit, a4_height, x_left_spine_limit, 0)
 200                 c.line(x_right_spine_limit, a4_height, x_right_spine_limit, 0)
 201             if front_page:
 202                 c.setLineWidth(0.2)
 203                 cut_depth = 19.5 * points_per_mm
 204                 cut_width = 10.5 * points_per_mm
 205                 middle_point_depth = 4 * points_per_mm
 206
 207                 start_up_left_left_x = x_left_spine_limit - 0.5 * cut_width
 208                 start_up_left_right_x = x_left_spine_limit + 0.5 * cut_width
 209                 middle_point_up_left_y = half_height + middle_point_depth
 210                 end_point_up_left_y = half_height + cut_depth
 211                 c.line(start_up_left_right_x, half_height, x_left_spine_limit, end_point_up_left_y)
 212                 c.line(x_left_spine_limit, end_point_up_left_y, x_left_spine_limit, middle_point_up_left_y)
 213                 c.line(x_left_spine_limit, middle_point_up_left_y, start_up_left_left_x, half_height)
 214
 215                 start_down_right_left_x = x_right_spine_limit - 0.5 * cut_width
 216                 start_down_right_right_x = x_right_spine_limit + 0.5 * cut_width
 217                 middle_point_down_right_y = half_height - middle_point_depth
 218                 end_point_down_right_y = half_height - cut_depth
 219                 c.line(start_down_right_left_x, half_height, x_right_spine_limit, end_point_down_right_y)
 220                 c.line(x_right_spine_limit, end_point_down_right_y, x_right_spine_limit, middle_point_down_right_y)
 221                 c.line(x_right_spine_limit, middle_point_down_right_y, start_down_right_right_x, half_height)
 222
 223             if args.analyze or front_page:
 224                 c.save()
 225                 new_pdf = pypdf.PdfReader(packet)
 226                 new_page.merge_page(new_pdf.pages[0])
 227             writer.add_page(new_page)
 228             i = 0
 229             front_page = not front_page
 230 for file in opened_files:
 231     file.close()
 232
 233 with open(args.output_file, 'wb') as output_file:
 234     writer.write(output_file)