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_file", action="append", required=True, help="input PDF file")
  10 parser.add_argument("-o", "--output_file", required=True, help="output PDF file")
  11 parser.add_argument("-p", "--page_range", action="append", help="page range, e.g., '3-end'")
  12 parser.add_argument("-c", "--crop_range", action="append", help="crops left, bottom, right, top – e.g., '10,10,10,10'; prefix with ':'-delimited page range to limit effect")
  13 parser.add_argument("-n", "--nup4", action='store_true', help="puts 4 input pages onto 1 output page")
  14 parser.add_argument("-a", "--analyze", action="store_true", help="print lines identifying spine, page borders")
  15 parser.add_argument("-t", "--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 in mm (default 4.3)")
  18 parser.add_argument("-s", "--spine", type=float, default=10, help="on --nup4, mm width of margin hidden in spine (default 10)")
  19 args = parser.parse_args()
  20
  21
  22 # select pages from input files
  23 def parse_page_range(range_string, pages):
  24     start_page = 0
  25     end_page = len(pages)
  26     if range_string:
  27         start, end = range_string.split('-')
  28         if not (len(start) == 0 or start == "start"):
  29             start_page = int(start) - 1
  30         if not (len(end) == 0 or end == "end"):
  31             end_page = int(end)
  32     return start_page, end_page
  33 pages_to_add = []
  34 opened_files = []
  35 for i, input_file in enumerate(args.input_file):
  36     file = open(input_file, 'rb')
  37     opened_files += [file]
  38     reader = pypdf.PdfReader(file)
  39     range_string = None
  40     if args.page_range and len(args.page_range) > i:
  41         range_string = args.page_range[i]
  42     start_page, end_page = parse_page_range(range_string, reader.pages)
  43     for page_num in range(start_page, end_page):
  44         page = reader.pages[page_num]
  45         pages_to_add += [page]
  46         print("read in %s page number %d" % (input_file, page_num+1))
  47
  48 # rotate page canvas
  49 if args.rotate:
  50     for rotate in args.rotate:
  51         page = pages_to_add[rotate - 1]
  52         page.add_transformation(pypdf.Transformation().translate(tx=-a4_width/2, ty=-a4_height/2))
  53         page.add_transformation(pypdf.Transformation().rotate(-90))
  54         page.add_transformation(pypdf.Transformation().translate(tx=a4_width/2, ty=a4_height/2))
  55
  56 # normalize all pages to portrait A4
  57 for page in pages_to_add:
  58     if "/Rotate" in page:
  59         page.rotate(360 - page["/Rotate"])
  60     page.mediabox.left = 0
  61     page.mediabox.bottom = 0
  62     page.mediabox.top = a4_height
  63     page.mediabox.right = a4_width
  64     page.cropbox = page.mediabox
  65
  66 # determine page crops, zooms
  67 crops_at_page = [(0,0,0,0)]*len(pages_to_add)
  68 zoom_at_page = [1]*len(pages_to_add)
  69 if args.crop_range:
  70   for crop_range in args.crop_range:
  71       initial_split = crop_range.split(':')
  72       if len(initial_split) > 1:
  73           page_range = initial_split[0]
  74           crops = initial_split[1]
  75       else:
  76           page_range = None
  77           crops = initial_split[0]
  78       start_page, end_page = parse_page_range(page_range, pages_to_add)
  79       crop_left, crop_bottom, crop_right, crop_top = [float(x) for x in  crops.split(',')]
  80       cropped_width  = a4_width - crop_left - crop_right
  81       cropped_height = a4_height - crop_bottom - crop_top
  82       zoom = 1
  83       zoom_horizontal = a4_width / (a4_width - crop_left - crop_right)
  84       zoom_vertical = a4_height / (a4_height - crop_bottom - crop_top)
  85       if (zoom_horizontal > 1 and zoom_vertical < 1) or (zoom_horizontal < 1 and zoom_vertical > 1):
  86           print("Error: opposing zooms.")
  87           exit(1)
  88       elif zoom_horizontal + zoom_vertical > 2:
  89           zoom = min(zoom_horizontal, zoom_vertical)
  90       else:
  91           zoom = max(zoom_horizontal, zoom_vertical)
  92       for page_num in range(start_page, end_page):
  93           crops_at_page[page_num] = (crop_left, crop_bottom, crop_right, crop_top)
  94           zoom_at_page[page_num] = zoom
  95
  96 writer = pypdf.PdfWriter()
  97 if not args.nup4:
  98     odd_page = True
  99     for i, page in enumerate(pages_to_add):
 100         crop_left, crop_bottom, crop_right, crop_top = crops_at_page[i]
 101         zoom = zoom_at_page[i]
 102         if args.symmetry and odd_page:
 103             page.add_transformation(pypdf.Transformation().translate(tx=-crop_right, ty=-crop_bottom))
 104         else:
 105             page.add_transformation(pypdf.Transformation().translate(tx=-crop_left, ty=-crop_bottom))
 106         page.add_transformation(pypdf.Transformation().scale(zoom, zoom))
 107         cropped_width  = a4_width - crop_left - crop_right
 108         cropped_height = a4_height - crop_bottom - crop_top
 109         page.mediabox.right = cropped_width * zoom
 110         page.mediabox.top = cropped_height * zoom
 111         writer.add_page(page)
 112         odd_page = not odd_page
 113
 114 else:
 115     points_per_mm = 2.83465
 116     n_pages_per_axis = 2
 117     spine_limit = args.spine * points_per_mm
 118     printable_margin = args.margin * points_per_mm
 119     printable_scale = (a4_width - 2*printable_margin)/a4_width
 120     half_width = a4_width / n_pages_per_axis
 121     half_height = a4_height / n_pages_per_axis
 122     section_scale_factor = 1 / n_pages_per_axis
 123     spine_part_of_page = (spine_limit / half_width) / printable_scale
 124     bonus_shrink_factor = 1 - spine_part_of_page
 125     new_page_order = []
 126     new_i_order = []
 127     eight_pack = []
 128     mod_to_8 = len(pages_to_add) % 8
 129     if mod_to_8 > 0:
 130         for _ in range(8 - mod_to_8):
 131             new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
 132             pages_to_add += [new_page]
 133     i = 0
 134     n_eights = 0
 135     for page in pages_to_add:
 136         if i == 0:
 137             eight_pack = []
 138         eight_pack += [page]
 139         i += 1
 140         if i == 8:
 141             i = 0
 142             new_i_order += [8 * n_eights + 3,
 143                             8 * n_eights + 0,
 144                             8 * n_eights + 7,
 145                             8 * n_eights + 4,
 146                             8 * n_eights + 1,
 147                             8 * n_eights + 2,
 148                             8 * n_eights + 5,
 149                             8 * n_eights + 6]
 150             n_eights += 1
 151             new_page_order += [eight_pack[3]]  # page front, upper left
 152             new_page_order += [eight_pack[0]]  # page front, upper right
 153             new_page_order += [eight_pack[7]]  # page front, lower left
 154             new_page_order += [eight_pack[4]]  # page front, lower right
 155             new_page_order += [eight_pack[1]]  # page back, upper left
 156             new_page_order += [eight_pack[2]]  # page back, upper right
 157             new_page_order += [eight_pack[5]]  # page back, lower left
 158             new_page_order += [eight_pack[6]]  # page back, lower right
 159     i = 0
 160     page_count = 0
 161     front_page = True
 162     for j, page in enumerate(new_page_order):
 163         if i == 0:
 164             new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
 165
 166         # in-section transformations: align pages on top, left-hand pages to left, right-hand to right
 167         new_i = new_i_order[j]
 168         crop_left, crop_bottom, crop_right, crop_top = crops_at_page[new_i]
 169         zoom = zoom_at_page[new_i]
 170         page.add_transformation(pypdf.Transformation().translate(ty=(a4_height / zoom - (a4_height - crop_top))))
 171         if i == 0 or i == 2:
 172             if args.symmetry:
 173                 page.add_transformation(pypdf.Transformation().translate(tx=-crop_left))
 174             else:
 175                 page.add_transformation(pypdf.Transformation().translate(tx=-crop_right))
 176         elif i == 1 or i == 3:
 177             if args.symmetry:
 178                 page.add_transformation(pypdf.Transformation().translate(tx=(a4_width / zoom - (a4_width - crop_left))))
 179             else:
 180                 page.add_transformation(pypdf.Transformation().translate(tx=(a4_width / zoom - (a4_width - crop_right))))
 181         page.add_transformation(pypdf.Transformation().scale(zoom * bonus_shrink_factor, zoom * bonus_shrink_factor))
 182         if i == 2 or i == 3:
 183             page.add_transformation(pypdf.Transformation().translate(ty=-2*printable_margin/printable_scale))
 184
 185         # outer section transformations
 186         page.add_transformation(pypdf.Transformation().translate(ty=(1-bonus_shrink_factor)*a4_height))
 187         if i == 0 or i == 1:
 188             y_section = a4_height
 189             page.mediabox.bottom = half_height
 190             page.mediabox.top    = a4_height
 191         if i == 2 or i == 3:
 192             y_section = 0
 193             page.mediabox.bottom = 0
 194             page.mediabox.top  =   half_height
 195         if i == 0 or i == 2:
 196             x_section = 0
 197             page.mediabox.left   = 0
 198             page.mediabox.right  = half_width
 199         if i == 1 or i == 3:
 200             page.add_transformation(pypdf.Transformation().translate(tx=(1-bonus_shrink_factor)*a4_width))
 201             x_section = a4_width
 202             page.mediabox.left   = half_width
 203             page.mediabox.right  = a4_width
 204         page.add_transformation(pypdf.Transformation().translate(tx=x_section, ty=y_section))
 205         page.add_transformation(pypdf.Transformation().scale(section_scale_factor, section_scale_factor))
 206         new_page.merge_page(page)
 207         page_count += 1
 208         print("merged page number", page_count)
 209         i += 1
 210         if i > 3:
 211             from reportlab.pdfgen import canvas
 212             if args.analyze:
 213                 # borders
 214                 packet = io.BytesIO()
 215                 c = canvas.Canvas(packet, pagesize=A4)
 216                 c.setLineWidth(0.1)
 217                 c.line(0, a4_height, a4_width, a4_height)
 218                 c.line(0, half_height, a4_width, half_height)
 219                 c.line(0, 0, a4_width, 0)
 220                 c.line(0, a4_height, 0, 0)
 221                 c.line(half_width, a4_height, half_width, 0)
 222                 c.line(a4_width, a4_height, a4_width, 0)
 223                 c.save()
 224                 new_pdf = pypdf.PdfReader(packet)
 225                 new_page.merge_page(new_pdf.pages[0])
 226             printable_offset_x = printable_margin
 227             printable_offset_y = printable_margin * a4_height / a4_width
 228             new_page.add_transformation(pypdf.Transformation().scale(printable_scale, printable_scale))
 229             new_page.add_transformation(pypdf.Transformation().translate(tx=printable_offset_x, ty=printable_offset_y))
 230             x_left_spine_limit = half_width * bonus_shrink_factor
 231             x_right_spine_limit = a4_width - x_left_spine_limit
 232             if args.analyze or front_page:
 233                 packet = io.BytesIO()
 234                 c = canvas.Canvas(packet, pagesize=A4)
 235             if args.analyze:
 236                 # # spine lines
 237                 c.setLineWidth(0.1)
 238                 c.line(x_left_spine_limit, a4_height, x_left_spine_limit, 0)
 239                 c.line(x_right_spine_limit, a4_height, x_right_spine_limit, 0)
 240             if front_page:
 241                 c.setLineWidth(0.2)
 242                 cut_depth = 19.5 * points_per_mm
 243                 cut_width = 10.5 * points_per_mm
 244                 middle_point_depth = 4 * points_per_mm
 245
 246                 start_up_left_left_x = x_left_spine_limit - 0.5 * cut_width
 247                 start_up_left_right_x = x_left_spine_limit + 0.5 * cut_width
 248                 middle_point_up_left_y = half_height + middle_point_depth
 249                 end_point_up_left_y = half_height + cut_depth
 250                 c.line(start_up_left_right_x, half_height, x_left_spine_limit, end_point_up_left_y)
 251                 c.line(x_left_spine_limit, end_point_up_left_y, x_left_spine_limit, middle_point_up_left_y)
 252                 c.line(x_left_spine_limit, middle_point_up_left_y, start_up_left_left_x, half_height)
 253
 254                 start_down_right_left_x = x_right_spine_limit - 0.5 * cut_width
 255                 start_down_right_right_x = x_right_spine_limit + 0.5 * cut_width
 256                 middle_point_down_right_y = half_height - middle_point_depth
 257                 end_point_down_right_y = half_height - cut_depth
 258                 c.line(start_down_right_left_x, half_height, x_right_spine_limit, end_point_down_right_y)
 259                 c.line(x_right_spine_limit, end_point_down_right_y, x_right_spine_limit, middle_point_down_right_y)
 260                 c.line(x_right_spine_limit, middle_point_down_right_y, start_down_right_right_x, half_height)
 261
 262             if args.analyze or front_page:
 263                 c.save()
 264                 new_pdf = pypdf.PdfReader(packet)
 265                 new_page.merge_page(new_pdf.pages[0])
 266             writer.add_page(new_page)
 267             i = 0
 268             front_page = not front_page
 269 for file in opened_files:
 270     file.close()
 271
 272 with open(args.output_file, 'wb') as output_file:
 273     writer.write(output_file)