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 points_per_cm = 10 * 72 / 25.4
   8 cut_depth = 1.95 * points_per_cm
   9 cut_width = 1.05 * points_per_cm
  10 middle_point_depth = 0.4 * points_per_cm
  11
  12 parser = argparse.ArgumentParser(description="build print-ready book PDF")
  13 parser.add_argument("-i", "--input_file", action="append", required=True, help="input PDF file")
  14 parser.add_argument("-o", "--output_file", required=True, help="output PDF file")
  15 parser.add_argument("-p", "--page_range", action="append", help="page range, e.g., '3-end'")
  16 parser.add_argument("-c", "--crop_range", action="append", help="cm crops left, bottom, right, top – e.g., '10,10,10,10'; prefix with ':'-delimited page range to limit effect")
  17 parser.add_argument("-t", "--symmetry", action="store_true", help="alternate horizontal crops between odd and even pages")
  18 parser.add_argument("-r", "--rotate", dest="rotate", type=int, action="append", help="rotate page of number by 90° (usable multiple times on same page!)")
  19 parser.add_argument("-n", "--nup4", action='store_true', help="puts 4 input pages onto 1 output page")
  20 parser.add_argument("-a", "--analyze", action="store_true", help="in --nup4, print lines identifying spine, page borders")
  21 parser.add_argument("-m", "--margin", type=float, default=0.43, help="print margin for --nup4 in cm (default 0.43)")
  22 parser.add_argument("-s", "--spine", type=float, default=1, help="on --nup4, cm width of margin hidden in spine (default 1)")
  23 args = parser.parse_args()
  24
  25
  26 # select pages from input files
  27 def parse_page_range(range_string, pages):
  28     start_page = 0
  29     end_page = len(pages)
  30     if range_string:
  31         start, end = range_string.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     return start_page, end_page
  37 pages_to_add = []
  38 opened_files = []
  39 new_page_num = 0
  40 for i, input_file in enumerate(args.input_file):
  41     file = open(input_file, 'rb')
  42     opened_files += [file]
  43     reader = pypdf.PdfReader(file)
  44     range_string = None
  45     if args.page_range and len(args.page_range) > i:
  46         range_string = args.page_range[i]
  47     start_page, end_page = parse_page_range(range_string, reader.pages)
  48     for old_page_num in range(start_page, end_page):
  49         new_page_num += 1
  50         page = reader.pages[old_page_num]
  51         pages_to_add += [page]
  52         print("-i, -p: read in %s page number %d as new page %d" % (input_file, old_page_num+1, new_page_num))
  53
  54 # rotate page canvas
  55 if args.rotate:
  56     for rotate in args.rotate:
  57         page = pages_to_add[rotate - 1]
  58         page.add_transformation(pypdf.Transformation().translate(tx=-a4_width/2, ty=-a4_height/2))
  59         page.add_transformation(pypdf.Transformation().rotate(-90))
  60         page.add_transformation(pypdf.Transformation().translate(tx=a4_width/2, ty=a4_height/2))
  61         print("-r: rotating (by 90°) page", rotate)
  62
  63 # normalize all pages to portrait A4
  64 for page in pages_to_add:
  65     if "/Rotate" in page:
  66         page.rotate(360 - page["/Rotate"])
  67     page.mediabox.left = 0
  68     page.mediabox.bottom = 0
  69     page.mediabox.top = a4_height
  70     page.mediabox.right = a4_width
  71     page.cropbox = page.mediabox
  72
  73 # determine page crops, zooms
  74 crops_at_page = [(0,0,0,0)]*len(pages_to_add)
  75 zoom_at_page = [1]*len(pages_to_add)
  76 if args.crop_range:
  77   for crop_range in args.crop_range:
  78       initial_split = crop_range.split(':')
  79       if len(initial_split) > 1:
  80           page_range = initial_split[0]
  81           crops = initial_split[1]
  82       else:
  83           page_range = None
  84           crops = initial_split[0]
  85       start_page, end_page = parse_page_range(page_range, pages_to_add)
  86       crop_left, crop_bottom, crop_right, crop_top = [float(x) * points_per_cm for x in  crops.split(',')]
  87       if args.symmetry:
  88           print("-c, -t: to pages %d to %d applying crops: left %dcm, bottom %dcm, right %dcm, top %dcm (but alternating left and right crop between even and odd pages)" % (start_page + 1, end_page, crop_left, crop_bottom, crop_right, crop_top))
  89       else:
  90           print("-c: to pages %d to %d applying crops: left %dcm, bottom %dcm, right %dcm, top %dcm" % (start_page + 1, end_page, crop_left, crop_bottom, crop_right, crop_top))
  91       cropped_width  = a4_width - crop_left - crop_right
  92       cropped_height = a4_height - crop_bottom - crop_top
  93       zoom = 1
  94       zoom_horizontal = a4_width / (a4_width - crop_left - crop_right)
  95       zoom_vertical = a4_height / (a4_height - crop_bottom - crop_top)
  96       if (zoom_horizontal > 1 and zoom_vertical < 1) or (zoom_horizontal < 1 and zoom_vertical > 1):
  97           print("Error: opposing zooms.")
  98           exit(1)
  99       elif zoom_horizontal + zoom_vertical > 2:
 100           zoom = min(zoom_horizontal, zoom_vertical)
 101       else:
 102           zoom = max(zoom_horizontal, zoom_vertical)
 103       for page_num in range(start_page, end_page):
 104           if args.symmetry and page_num % 2:
 105               crops_at_page[page_num] = (crop_right, crop_bottom, crop_left, crop_top)
 106           else:
 107               crops_at_page[page_num] = (crop_left, crop_bottom, crop_right, crop_top)
 108           zoom_at_page[page_num] = zoom
 109
 110 writer = pypdf.PdfWriter()
 111 if not args.nup4:
 112     odd_page = True
 113     for i, page in enumerate(pages_to_add):
 114         crop_left, crop_bottom, crop_right, crop_top = crops_at_page[i]
 115         zoom = zoom_at_page[i]
 116         page.add_transformation(pypdf.Transformation().translate(tx=-crop_left, ty=-crop_bottom))
 117         page.add_transformation(pypdf.Transformation().scale(zoom, zoom))
 118         cropped_width  = a4_width - crop_left - crop_right
 119         cropped_height = a4_height - crop_bottom - crop_top
 120         page.mediabox.right = cropped_width * zoom
 121         page.mediabox.top = cropped_height * zoom
 122         writer.add_page(page)
 123         odd_page = not odd_page
 124
 125 else:
 126     n_pages_per_axis = 2
 127     spine_limit = args.spine * points_per_cm
 128     printable_margin = args.margin * points_per_cm
 129     printable_scale = (a4_width - 2*printable_margin)/a4_width
 130     half_width = a4_width / n_pages_per_axis
 131     half_height = a4_height / n_pages_per_axis
 132     section_scale_factor = 1 / n_pages_per_axis
 133     spine_part_of_page = (spine_limit / half_width) / printable_scale
 134     bonus_shrink_factor = 1 - spine_part_of_page
 135     new_page_order = []
 136     new_i_order = []
 137     eight_pack = []
 138     mod_to_8 = len(pages_to_add) % 8
 139     if mod_to_8 > 0:
 140         for _ in range(8 - mod_to_8):
 141             new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
 142             pages_to_add += [new_page]
 143     i = 0
 144     n_eights = 0
 145     for page in pages_to_add:
 146         if i == 0:
 147             eight_pack = []
 148         eight_pack += [page]
 149         i += 1
 150         if i == 8:
 151             i = 0
 152             new_i_order += [8 * n_eights + 3,
 153                             8 * n_eights + 0,
 154                             8 * n_eights + 7,
 155                             8 * n_eights + 4,
 156                             8 * n_eights + 1,
 157                             8 * n_eights + 2,
 158                             8 * n_eights + 5,
 159                             8 * n_eights + 6]
 160             n_eights += 1
 161             new_page_order += [eight_pack[3]]  # page front, upper left
 162             new_page_order += [eight_pack[0]]  # page front, upper right
 163             new_page_order += [eight_pack[7]]  # page front, lower left
 164             new_page_order += [eight_pack[4]]  # page front, lower right
 165             new_page_order += [eight_pack[1]]  # page back, upper left
 166             new_page_order += [eight_pack[2]]  # page back, upper right
 167             new_page_order += [eight_pack[5]]  # page back, lower left
 168             new_page_order += [eight_pack[6]]  # page back, lower right
 169     i = 0
 170     page_count = 0
 171     front_page = True
 172     for j, page in enumerate(new_page_order):
 173         if i == 0:
 174             new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
 175
 176         # in-section transformations: align pages on top, left-hand pages to left, right-hand to right
 177         new_i = new_i_order[j]
 178         crop_left, crop_bottom, crop_right, crop_top = crops_at_page[new_i]
 179         zoom = zoom_at_page[new_i]
 180         page.add_transformation(pypdf.Transformation().translate(ty=(a4_height / zoom - (a4_height - crop_top))))
 181         if i == 0 or i == 2:
 182             page.add_transformation(pypdf.Transformation().translate(tx=-crop_left))
 183         elif i == 1 or i == 3:
 184             page.add_transformation(pypdf.Transformation().translate(tx=(a4_width / zoom - (a4_width - crop_right))))
 185         page.add_transformation(pypdf.Transformation().scale(zoom * bonus_shrink_factor, zoom * bonus_shrink_factor))
 186         if i == 2 or i == 3:
 187             page.add_transformation(pypdf.Transformation().translate(ty=-2*printable_margin/printable_scale))
 188
 189         # outer section transformations
 190         page.add_transformation(pypdf.Transformation().translate(ty=(1-bonus_shrink_factor)*a4_height))
 191         if i == 0 or i == 1:
 192             y_section = a4_height
 193             page.mediabox.bottom = half_height
 194             page.mediabox.top    = a4_height
 195         if i == 2 or i == 3:
 196             y_section = 0
 197             page.mediabox.bottom = 0
 198             page.mediabox.top  =   half_height
 199         if i == 0 or i == 2:
 200             x_section = 0
 201             page.mediabox.left   = 0
 202             page.mediabox.right  = half_width
 203         if i == 1 or i == 3:
 204             page.add_transformation(pypdf.Transformation().translate(tx=(1-bonus_shrink_factor)*a4_width))
 205             x_section = a4_width
 206             page.mediabox.left   = half_width
 207             page.mediabox.right  = a4_width
 208         page.add_transformation(pypdf.Transformation().translate(tx=x_section, ty=y_section))
 209         page.add_transformation(pypdf.Transformation().scale(section_scale_factor, section_scale_factor))
 210         new_page.merge_page(page)
 211         page_count += 1
 212         print("merged page number", page_count)
 213         i += 1
 214         if i > 3:
 215             from reportlab.pdfgen import canvas
 216             if args.analyze:
 217                 # borders
 218                 packet = io.BytesIO()
 219                 c = canvas.Canvas(packet, pagesize=A4)
 220                 c.setLineWidth(0.1)
 221                 c.line(0, a4_height, a4_width, a4_height)
 222                 c.line(0, half_height, a4_width, half_height)
 223                 c.line(0, 0, a4_width, 0)
 224                 c.line(0, a4_height, 0, 0)
 225                 c.line(half_width, a4_height, half_width, 0)
 226                 c.line(a4_width, a4_height, a4_width, 0)
 227                 c.save()
 228                 new_pdf = pypdf.PdfReader(packet)
 229                 new_page.merge_page(new_pdf.pages[0])
 230             printable_offset_x = printable_margin
 231             printable_offset_y = printable_margin * a4_height / a4_width
 232             new_page.add_transformation(pypdf.Transformation().scale(printable_scale, printable_scale))
 233             new_page.add_transformation(pypdf.Transformation().translate(tx=printable_offset_x, ty=printable_offset_y))
 234             x_left_spine_limit = half_width * bonus_shrink_factor
 235             x_right_spine_limit = a4_width - x_left_spine_limit
 236             if args.analyze or front_page:
 237                 packet = io.BytesIO()
 238                 c = canvas.Canvas(packet, pagesize=A4)
 239             if args.analyze:
 240                 # # spine lines
 241                 c.setLineWidth(0.1)
 242                 c.line(x_left_spine_limit, a4_height, x_left_spine_limit, 0)
 243                 c.line(x_right_spine_limit, a4_height, x_right_spine_limit, 0)
 244             if front_page:
 245                 c.setLineWidth(0.2)
 246
 247                 start_up_left_left_x = x_left_spine_limit - 0.5 * cut_width
 248                 start_up_left_right_x = x_left_spine_limit + 0.5 * cut_width
 249                 middle_point_up_left_y = half_height + middle_point_depth
 250                 end_point_up_left_y = half_height + cut_depth
 251                 c.line(start_up_left_right_x, half_height, x_left_spine_limit, end_point_up_left_y)
 252                 c.line(x_left_spine_limit, end_point_up_left_y, x_left_spine_limit, middle_point_up_left_y)
 253                 c.line(x_left_spine_limit, middle_point_up_left_y, start_up_left_left_x, half_height)
 254
 255                 start_down_right_left_x = x_right_spine_limit - 0.5 * cut_width
 256                 start_down_right_right_x = x_right_spine_limit + 0.5 * cut_width
 257                 middle_point_down_right_y = half_height - middle_point_depth
 258                 end_point_down_right_y = half_height - cut_depth
 259                 c.line(start_down_right_left_x, half_height, x_right_spine_limit, end_point_down_right_y)
 260                 c.line(x_right_spine_limit, end_point_down_right_y, x_right_spine_limit, middle_point_down_right_y)
 261                 c.line(x_right_spine_limit, middle_point_down_right_y, start_down_right_right_x, half_height)
 262
 263             if args.analyze or front_page:
 264                 c.save()
 265                 new_pdf = pypdf.PdfReader(packet)
 266                 new_page.merge_page(new_pdf.pages[0])
 267             writer.add_page(new_page)
 268             i = 0
 269             front_page = not front_page
 270
 271 # write and close
 272 for file in opened_files:
 273     file.close()
 274 with open(args.output_file, 'wb') as output_file:
 275     writer.write(output_file)