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", 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", 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("-s", "--second", dest="second", help="append second file as input to append")
  17 args = parser.parse_args()
  18
  19 with open(args.input_file, 'rb') as file:
  20     reader = pypdf.PdfReader(file)
  21
  22     # determine page range
  23     start_page = 0
  24     end_page = len(reader.pages)
  25     if args.page_range:
  26         start, end = args.page_range.split('-')
  27         if not (len(start) == 0 or start == "start"):
  28             start_page = int(start) - 1
  29         if not (len(end) == 0 or end == "end"):
  30             end_page = int(end)
  31     pages_to_add = []
  32     for page_num in range(start_page, end_page):
  33         page = reader.pages[page_num]
  34         pages_to_add += [page]
  35         print("read in page number", page_num+1)
  36
  37     # add pages of second PDF
  38     if args.second:
  39         file2 = open(args.second, 'rb')
  40         reader2 = pypdf.PdfReader(file2)
  41         page_num = 1
  42         for page in reader2.pages:
  43             pages_to_add += [page]
  44             print("read second PDF's page number", page_num)
  45             page_num += 1
  46
  47     # normalize all pages to A4
  48     for page in pages_to_add:
  49         page.mediabox.left = 0
  50         page.mediabox.bottom = 0
  51         page.mediabox.top = a4_height
  52         page.mediabox.right = a4_width
  53         page.cropbox = page.mediabox
  54
  55     # determine page crop
  56     crop_left, crop_bottom, crop_right, crop_top = 0, 0, 0, 0
  57     if args.crop_range:
  58         crop_left, crop_bottom, crop_right, crop_top = [float(x) for x in  args.crop_range.split(',')]
  59     cropped_width  = a4_width - crop_left - crop_right
  60     cropped_height = a4_height - crop_bottom - crop_top
  61     zoom = 1
  62     if args.crop_range:
  63         zoom_horizontal = a4_width / (a4_width - crop_left - crop_right)
  64         zoom_vertical = a4_height / (a4_height - crop_bottom - crop_top)
  65         if (zoom_horizontal > 1 and zoom_vertical < 1) or (zoom_horizontal < 1 and zoom_vertical > 1):
  66             print("Error: opposing zooms.")
  67             exit(1)
  68         elif zoom_horizontal + zoom_vertical > 2:
  69             zoom = min(zoom_horizontal, zoom_vertical)
  70         else:
  71             zoom = max(zoom_horizontal, zoom_vertical)
  72
  73     writer = pypdf.PdfWriter()
  74     if not args.nup4:
  75         odd_page = True
  76         for page in pages_to_add:
  77             if args.symmetry and odd_page:
  78                 page.add_transformation(pypdf.Transformation().translate(tx=-crop_left, ty=-crop_bottom))
  79             else:
  80                 page.add_transformation(pypdf.Transformation().translate(tx=-crop_right, ty=-crop_bottom))
  81             page.add_transformation(pypdf.Transformation().scale(zoom, zoom))
  82             page.mediabox.right = cropped_width * zoom
  83             page.mediabox.top = cropped_height * zoom
  84             writer.add_page(page)
  85             odd_page = not odd_page
  86     else:
  87         n_pages_per_axis = 2
  88         points_per_mm = 2.83465
  89         printable_margin = 4.3 * points_per_mm
  90         printable_scale = (a4_width - 2*printable_margin)/a4_width
  91         spine_limit = 10 * points_per_mm
  92         half_width = a4_width / n_pages_per_axis
  93         half_height = a4_height / n_pages_per_axis
  94         section_scale_factor = 1 / n_pages_per_axis
  95         spine_part_of_page = (spine_limit / half_width) / printable_scale
  96         bonus_shrink_factor = 1 - spine_part_of_page
  97         new_page_order = []
  98         eight_pack = []
  99         mod_to_8 = len(pages_to_add) % 8
 100         if mod_to_8 > 0:
 101             for _ in range(8 - mod_to_8):
 102                 new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
 103                 pages_to_add += [new_page]
 104         i = 0
 105         for page in pages_to_add:
 106             if i == 0:
 107                 eight_pack = []
 108             eight_pack += [page]
 109             i += 1
 110             if i == 8:
 111                 i = 0
 112                 new_page_order += [eight_pack[3]]  # page front, upper left
 113                 new_page_order += [eight_pack[0]]  # page front, upper right
 114                 new_page_order += [eight_pack[7]]  # page front, lower left
 115                 new_page_order += [eight_pack[4]]  # page front, lower right
 116                 new_page_order += [eight_pack[1]]  # page back, upper left
 117                 new_page_order += [eight_pack[2]]  # page back, upper right
 118                 new_page_order += [eight_pack[5]]  # page back, lower left
 119                 new_page_order += [eight_pack[6]]  # page back, lower right
 120         i = 0
 121         page_count = 0
 122         front_page = True
 123         for page in new_page_order:
 124             if i == 0:
 125                 new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
 126
 127             # in-section transformations: align pages on top, left-hand pages to left, right-hand to right
 128             page.add_transformation(pypdf.Transformation().translate(ty=(a4_height / zoom - (a4_height - crop_top))))
 129             if i == 0 or i == 2:
 130                 if args.symmetry:
 131                     page.add_transformation(pypdf.Transformation().translate(tx=-crop_right))
 132                 else:
 133                     page.add_transformation(pypdf.Transformation().translate(tx=-crop_left))
 134             elif i == 1 or i == 3:
 135                 page.add_transformation(pypdf.Transformation().translate(tx=(a4_width / zoom - (a4_width - crop_right))))
 136             page.add_transformation(pypdf.Transformation().scale(zoom * bonus_shrink_factor, zoom * bonus_shrink_factor))
 137             if i == 2 or i == 3:
 138                 page.add_transformation(pypdf.Transformation().translate(ty=-2*printable_margin/printable_scale))
 139
 140             # outer section transformations
 141             page.add_transformation(pypdf.Transformation().translate(ty=(1-bonus_shrink_factor)*a4_height))
 142             if i == 0 or i == 1:
 143                 y_section = a4_height
 144                 page.mediabox.bottom = half_height
 145                 page.mediabox.top    = a4_height
 146             if i == 2 or i == 3:
 147                 y_section = 0
 148                 page.mediabox.bottom = 0
 149                 page.mediabox.top  =   half_height
 150             if i == 0 or i == 2:
 151                 x_section = 0
 152                 page.mediabox.left   = 0
 153                 page.mediabox.right  = half_width
 154             if i == 1 or i == 3:
 155                 page.add_transformation(pypdf.Transformation().translate(tx=(1-bonus_shrink_factor)*a4_width))
 156                 x_section = a4_width
 157                 page.mediabox.left   = half_width
 158                 page.mediabox.right  = a4_width
 159             page.add_transformation(pypdf.Transformation().translate(tx=x_section, ty=y_section))
 160             page.add_transformation(pypdf.Transformation().scale(section_scale_factor, section_scale_factor))
 161             new_page.merge_page(page)
 162             page_count += 1
 163             print("merged page number", page_count)
 164             i += 1
 165             if i > 3:
 166                 from reportlab.pdfgen import canvas
 167                 if args.analyze:
 168                     # borders
 169                     packet = io.BytesIO()
 170                     c = canvas.Canvas(packet, pagesize=A4)
 171                     c.setLineWidth(0.1)
 172                     c.line(0, a4_height, a4_width, a4_height)
 173                     c.line(0, half_height, a4_width, half_height)
 174                     c.line(0, 0, a4_width, 0)
 175                     c.line(0, a4_height, 0, 0)
 176                     c.line(half_width, a4_height, half_width, 0)
 177                     c.line(a4_width, a4_height, a4_width, 0)
 178                     c.save()
 179                     new_pdf = pypdf.PdfReader(packet)
 180                     new_page.merge_page(new_pdf.pages[0])
 181                 printable_offset_x = printable_margin
 182                 printable_offset_y = printable_margin * a4_height / a4_width
 183                 new_page.add_transformation(pypdf.Transformation().scale(printable_scale, printable_scale))
 184                 new_page.add_transformation(pypdf.Transformation().translate(tx=printable_offset_x, ty=printable_offset_y))
 185                 x_left_spine_limit = half_width * bonus_shrink_factor
 186                 x_right_spine_limit = a4_width - x_left_spine_limit
 187                 if args.analyze or front_page:
 188                     packet = io.BytesIO()
 189                     c = canvas.Canvas(packet, pagesize=A4)
 190                 if args.analyze:
 191                     # # spine lines
 192                     c.setLineWidth(0.1)
 193                     c.line(x_left_spine_limit, a4_height, x_left_spine_limit, 0)
 194                     c.line(x_right_spine_limit, a4_height, x_right_spine_limit, 0)
 195                 if front_page:
 196                     c.setLineWidth(0.2)
 197                     cut_depth = 19.5 * points_per_mm
 198                     cut_width = 10.5 * points_per_mm
 199                     middle_point_depth = 4 * points_per_mm
 200
 201                     start_up_left_left_x = x_left_spine_limit - 0.5 * cut_width
 202                     start_up_left_right_x = x_left_spine_limit + 0.5 * cut_width
 203                     middle_point_up_left_y = half_height + middle_point_depth
 204                     end_point_up_left_y = half_height + cut_depth
 205                     c.line(start_up_left_right_x, half_height, x_left_spine_limit, end_point_up_left_y)
 206                     c.line(x_left_spine_limit, end_point_up_left_y, x_left_spine_limit, middle_point_up_left_y)
 207                     c.line(x_left_spine_limit, middle_point_up_left_y, start_up_left_left_x, half_height)
 208
 209                     start_down_right_left_x = x_right_spine_limit - 0.5 * cut_width
 210                     start_down_right_right_x = x_right_spine_limit + 0.5 * cut_width
 211                     middle_point_down_right_y = half_height - middle_point_depth
 212                     end_point_down_right_y = half_height - cut_depth
 213                     c.line(start_down_right_left_x, half_height, x_right_spine_limit, end_point_down_right_y)
 214                     c.line(x_right_spine_limit, end_point_down_right_y, x_right_spine_limit, middle_point_down_right_y)
 215                     c.line(x_right_spine_limit, middle_point_down_right_y, start_down_right_right_x, half_height)
 216
 217                 if args.analyze or front_page:
 218                     c.save()
 219                     # packet.seek(0)
 220                     new_pdf = pypdf.PdfReader(packet)
 221                     new_page.merge_page(new_pdf.pages[0])
 222                 writer.add_page(new_page)
 223                 i = 0
 224                 front_page = not front_page
 225
 226     with open(args.output_file, 'wb') as output_file:
 227         writer.write(output_file)
 228     if args.second:
 229         file2.close()