1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713
|
(* \chaptertitle{PDFImage}{PDF Images} *)
open Pdfutil
open Pdfio
type pixel_layout =
| BPP1
| BPP8
| BPP24
| BPP48
type t =
| JPEG of bytes * float list option
| JPEG2000 of bytes * float list option
| JBIG2 of bytes * float list option
| Raw of int * int * pixel_layout * bytes
let string_of_layout = function
| BPP1 -> "BPP1"
| BPP8 -> "BPP8"
| BPP24 -> "BPP24"
| BPP48 -> "BPP48"
let string_of_image = function
| JPEG _ -> "JPEG"
| JPEG2000 _ -> "JPEG2000"
| JBIG2 _ -> "JBIG2"
| Raw (w, h, layout, data) ->
"RAW: " ^ string_of_int w ^ " " ^ string_of_int h
^ " " ^ string_of_layout layout ^ " bytes of data = "
^ string_of_int (bytes_size data)
let print_floats fs =
for x = 1 to Array.length fs do
print_float fs.(x - 1);
print_string " "
done;
print_string "\n"
(* Decodes an image in-place, given an array of floats. Assumes that output of Decode fits into same number of bits as input of Decode. FIXME: When might this not be true? *)
(* Invert the bits in a bytes *)
let invert_bits s =
for x = 0 to bytes_size s - 1 do
bset s x (bget s x lxor 255)
done
let decode fs bpc image =
(*i Printf.printf "decode, %i floats, BPC %i\n" (Array.length fs) bpc; i*)
match Array.length fs with
| 0 -> ()
| l when odd l -> raise (Pdf.PDFError "Bad /Decode")
| l ->
(* Check to see if it's the identity transform. If so, do nothing. *)
let ident = ref true in
for x = 0 to Array.length fs / 2 - 1 do
if fs.(x * 2) <> 0. || fs.(x * 2 + 1) <> 1. then clear ident
done;
(*i Printf.printf "ident: %b\n" !ident; i*)
if not !ident then
let interpolate dmin dmax x =
int_of_float (dmin +. (float x *. (dmax -. dmin) /. (2.0 ** float bpc -. 1.)))
in
let functions =
Array.init (l / 2) (function i -> interpolate (fs.(i * 2)) (fs.(i * 2 + 1)))
in
match bpc with
| 1 ->
(* For now, just recognise [1 0] *)
invert_bits image
| 2 -> (*iflprint "DECODE: 2 bit\n"; i*)()
| 4 -> (*iflprint "DECODE: 4 bit\n"; i*)()
| 8 ->
(*i flprint "DECODE: 8 bit\n";
print_floats fs; i*)
for p = 0 to bytes_size image - 1 do
bset image p ((functions.(p mod (l / 2))) (bget image p))
done
| 16 -> (*i flprint "16 bit"; i*) ()
| _ -> raise (Pdf.PDFError "Bad /Decode")
let decode_defaults pdf resources entry image =
match entry with
| None ->
begin match Pdf.lookup_direct pdf "/ColorSpace" image with
| None -> None
| Some cspace ->
match Pdfspace.read_colourspace pdf resources cspace with
| Pdfspace.DeviceGray | Pdfspace.CalGray (_, _, _) | Pdfspace.Separation (_, _, _) ->
Some (Pdf.Array [Pdf.Real 0.; Pdf.Real 1.])
| Pdfspace.DeviceRGB | Pdfspace.CalRGB (_, _, _, _) ->
Some (Pdf.Array [Pdf.Real 0.; Pdf.Real 1.; Pdf.Real 0.; Pdf.Real 1.;Pdf.Real 0.; Pdf.Real 1.])
| Pdfspace.DeviceCMYK ->
Some (Pdf.Array [Pdf.Real 0.; Pdf.Real 1.; Pdf.Real 0.; Pdf.Real 1.;Pdf.Real 0.; Pdf.Real 1.; Pdf.Real 0.; Pdf.Real 1.])
| Pdfspace.Lab (_, _, range) ->
Some (Pdf.Array ([Pdf.Real 0.; Pdf.Real 1.] @ map (function n -> Pdf.Real n) (Array.to_list range)))
| Pdfspace.ICCBased {Pdfspace.icc_range = range} ->
(*i flprint "Making default from ICCBased colour space\n"; i*)
Some (Pdf.Array (map (function n -> Pdf.Real n) (Array.to_list range)))
| Pdfspace.Indexed (_, _) ->
(*i flprint "Making default from Indexed colour space\n"; i*)
(*i let bpc =
match Pdf.lookup_direct_orelse pdf "/BitsPerComponent" "/BPC" image with
| Some (Pdf.Integer n) -> n
| _ -> 0
in i*) (* Commented out because we don't use it yet... *)
(* For now, just make identity. FIXME: How should decode /
indexed work - do it in the actual extraction routine? *)
Some (Pdf.Array [Pdf.Real 0.; Pdf.Real 1.])
(*i let n = 2.0 ** float bpc -. 1.0 in
Some (Pdf.Array [Pdf.Real 0.; Pdf.Real n]) i*)
| Pdfspace.Pattern -> None
| Pdfspace.PatternWithBaseColourspace _ -> None (* FIXME: Check this *)
| Pdfspace.DeviceN (arr, _, _, _) ->
Some (Pdf.Array (flatten (many [Pdf.Real 0.; Pdf.Real 1.] (Array.length arr))))
end
| x ->
match Pdf.lookup_direct pdf "/ColorSpace" image with
| None -> x (* Because image masks don't have a colourspace *)
| Some cspace ->
match Pdfspace.read_colourspace pdf resources cspace with
(* Again. A bodge. Need to sort out indexed decoding properly. *)
| Pdfspace.Indexed (_, _) -> None
| _ -> x
(* Decode until it is either plain or a type of decoding we can't deal with
natively. *)
let rec decode_to_image pdf = function
| Pdf.Stream {contents = d, s} as stream ->
begin match Pdf.lookup_direct pdf "/Filter" d with
| None
| Some (Pdf.Array [])
| Some (Pdf.Name ("/DCTDecode" | "/DCT" | "/JBIG2Decode" | "/JPXDecode"))
| Some (Pdf.Array [Pdf.Name ("/DCTDecode" | "/DCT" | "/JBIG2Decode" | "/JPXDecode")]) -> ()
| _ ->
Pdfcodec.decode_pdfstream_onestage pdf stream;
decode_to_image pdf stream
end
| _ -> raise (Pdf.PDFError "decode_to_image: bad stream")
(* Basic CMYK to RGB conversion *)
let rgb_of_cmyk c m y k =
let c = float c in let m = float m in let y = float y in let k = float k in
let r = 255. -. fmin 255. ((c /. 255.) *. (255. -. k) +. k)
in let g = 255. -. fmin 255. ((m /. 255.) *. (255. -. k) +. k)
in let b = 255. -. fmin 255. ((y /. 255.) *. (255. -. k) +. k) in
toint r, toint g, toint b
let read_cmyk_8bpp_as_rgb24 width height data =
let data' = mkbytes (width * height * 3) in
for p = 0 to width * height - 1 do
let c = bget data (p * 4)
in let m = bget data (p * 4 + 1)
in let y = bget data (p * 4 + 2)
in let k = bget data (p * 4 + 3) in
let r, g, b = rgb_of_cmyk c m y k in
bset data' (p * 3) r;
bset data' (p * 3 + 1) g;
bset data' (p * 3 + 2) b
done;
data'
let read_gray_8bpp_as_rgb24 width height data =
let data' = mkbytes (width * height * 3) in
for pout = 0 to width * height - 1 do
bset data' (pout * 3) (bget data pout);
bset data' (pout * 3 + 1) (bget data pout);
bset data' (pout * 3 + 2) (bget data pout);
done;
data'
(* Input is 1bpp, rows padded to bytes. *)
let read_1bpp_as_rgb24 width height s =
let s' = mkbytes (width * height * 3)
in let s_bits = Pdfio.bitbytes_of_input (Pdfio.input_of_bytes s) in
let pout = ref 0 in
for row = 0 to height - 1 do
let bits_to_do = ref width in
while !bits_to_do > 0 do
let bit = if Pdfio.getbit s_bits then 255 else 0 in
bset s' !pout bit;
bset s' (!pout + 1) bit;
bset s' (!pout + 2) bit;
decr bits_to_do;
pout += 3
done;
Pdfio.align s_bits
done;
s'
(* 4bpp, rows padded to bytes. *)
let read_4bpp_gray_as_rgb24 width height s =
let s' = mkbytes (width * height * 3)
in let s_bits = Pdfio.bitbytes_of_input (Pdfio.input_of_bytes s) in
let pout = ref 0 in
for row = 0 to height - 1 do
let pix_to_do = ref width in
while !pix_to_do > 0 do
let a = if Pdfio.getbit s_bits then 1 else 0 in
let b = if Pdfio.getbit s_bits then 1 else 0 in
let c = if Pdfio.getbit s_bits then 1 else 0 in
let d = if Pdfio.getbit s_bits then 1 else 0 in
let col = (a * 8 + b * 4 + c * 2 + d) * (16 + 1) in
bset s' !pout col;
bset s' (!pout + 1) col;
bset s' (!pout + 2) col;
decr pix_to_do;
pout += 3
done;
Pdfio.align s_bits
done;
s'
let read_8bpp_indexed_as_rgb24 table width height s =
let s' = mkbytes (width * height * 3) in
for x = 0 to width * height - 1 do
match Hashtbl.find table (bget s x) with
| [r; g; b] ->
bset s' (x * 3) r;
bset s' (x * 3 + 1) g;
bset s' (x * 3 + 2) b
| _ -> raise (Pdf.PDFError "read_8bpp_indexed_as_rgb24")
done;
s'
(* Clamp a value to 0.0...1.0 *)
let clamp10 f =
if f > 1.0 then 1.0 else if f < 0.0 then 0.0 else f
(* LAB colour space support *)
let xyz_of_lab l' a' b' xw yw zw =
let g x =
if x >= 6. /. 29.
then x *. x *. x
else (108. /. 841.) *. (x -. 4. /. 29.)
in
let l = (l' +. 16.) /. 116. +. a' /. 500.
in let m = (l' +. 16.) /. 116.
in let n = (l' +. 16.) /. 116. -. b' /. 200. in
clamp10 (xw *. g l),
clamp10 (yw *. g m),
clamp10 (zw *. g n)
(* For x, y, z on 0..1 calculate r, g, b on 0..1 *)
let rgb_of_xyz x y z =
clamp10 (2.5623 *. x +. -.1.1661 *. y +. -.0.3962 *. z),
clamp10 (-.1.0215 *. x +. 1.9778 *. y +. 0.0437 *. z),
clamp10 (0.0752 *. x +. -.0.2562 *. y +. 1.1810 *. z)
(* Assume indexed /Range of -127...128. FIXME *)
let convert_lab_to_rgb width height (xw, yw, zw) q rs s =
for p = 0 to width * height - 1 do
let l = bget s (p * 3) - 127
in let a = bget s (p * 3 + 1) - 127
in let b = bget s (p * 3 + 2) - 127 in
(*i Printf.printf "xw yw zw = %f, %f, %f\n" xw yw zw;
Printf.printf "l a b = %i, %i, %i\n" l a b; i*)
let l' = float l /. 255.
in let a' = float a /. 255.
in let b' = float b /. 255. in
(*i Printf.printf "l' a' b' = %f, %f, %f\n" l' a' b'; i*)
let x, y, z = xyz_of_lab l' a' b' xw yw zw in
(*i Printf.printf "x y z = %f, %f, %f\n" x y z; i*)
let r, g, b = rgb_of_xyz x y z in
(*i Printf.printf "r g b = %f, %f, %f\n" r g b; i*)
let r' = toint (r *. 255.)
in let g' = toint (g *. 255.)
in let b' = toint (b *. 255.) in
(*i Printf.printf "r', g', b' = %i, %i, %i\n" r' g' b'; i*)
bset s (p * 3) r';
bset s (p * 3 + 1) g';
bset s (p * 3 + 2) b'
done
let read_8bpp_lab_indexed_as_rgb24 table width height p q rs data =
let s = read_8bpp_indexed_as_rgb24 table width height data in
convert_lab_to_rgb width height p q rs s;
s
let read_8bpp_cmyk_indexed_as_rgb24 table width height s =
let s' = mkbytes (width * height * 3) in
for x = 0 to width * height - 1 do
match Hashtbl.find table (bget s x) with
| [c; m; y; k] ->
let r, g, b = rgb_of_cmyk c m y k in
bset s' (x * 3) r;
bset s' (x * 3 + 1) g;
bset s' (x * 3 + 2) b
| _ -> raise (Pdf.PDFError "read_8bpp_indexed_as_rgb24")
done;
s'
let read_4bpp_indexed_as_rgb24 table width height s =
let s' = mkbytes (width * height * 3) in
let posin = ref 0
in let posout = ref 0 in
for row = 0 to height - 1 do
for byte = 0 to (width + 1) / 2 - 1 do
let p1 = bget s !posin lsr 4
in let p2 = bget s !posin land 15 in
begin match Hashtbl.find table p1 with
| [r1; g1; b1] ->
bset s' !posout r1; incr posout;
bset s' !posout g1; incr posout;
bset s' !posout b1; incr posout;
| _ -> raise (Pdf.PDFError "read_4bpp_indexed_as_rgb24")
end;
begin
if not (odd width && byte = (width + 1) / 2 - 1) then
match Hashtbl.find table p2 with
| [r2; g2; b2] ->
bset s' !posout r2; incr posout;
bset s' !posout g2; incr posout;
bset s' !posout b2; incr posout;
| _ -> raise (Pdf.PDFError "read_4bpp_indexed_as_rgb24")
end;
incr posin
done
done;
s'
let read_4bpp_cmyk_indexed_as_rgb24 table width height s =
let s' = mkbytes (width * height * 3) in
let posin = ref 0
in let posout = ref 0 in
for row = 0 to height - 1 do
for byte = 0 to (width + 1) / 2 - 1 do
let p1 = bget s !posin lsr 4
in let p2 = bget s !posin land 15 in
begin match Hashtbl.find table p1 with
| [c; m; y; k] ->
let r1, g1, b1 = rgb_of_cmyk c m y k in
bset s' !posout r1; incr posout;
bset s' !posout g1; incr posout;
bset s' !posout b1; incr posout;
| _ -> raise (Pdf.PDFError "read_4bpp_cmyk_indexed_as_rgb24")
end;
begin
if not (odd width && byte = (width + 1) / 2 - 1) then
match Hashtbl.find table p2 with
| [c; m; y; k] ->
let r2, g2, b2 = rgb_of_cmyk c m y k in
bset s' !posout r2; incr posout;
bset s' !posout g2; incr posout;
bset s' !posout b2; incr posout;
| _ -> raise (Pdf.PDFError "read_4bpp_cmyk_indexed_as_rgb24")
end;
incr posin
done
done;
s'
(* Separation, CMYK alternate, tint transform function. *)
let read_separation_cmyk_as_rgb24 f width height s =
let s' = mkbytes (width * height * 3) in
for p = 0 to width * height - 1 do
let v = bget s p in
try
match Pdffun.eval_function f [float v /. 255.] with
| [c; y; m; k] ->
let c = toint (c *. 255.)
and m = toint (m *. 255.)
and y = toint (y *. 255.)
and k = toint (k *. 255.) in
let r, g, b = rgb_of_cmyk c m y k in
bset s' (p * 3) r;
bset s' (p * 3 + 1) g;
bset s' (p * 3 + 2) b;
| _ ->
raise (Pdf.PDFError "Bad tint transform function")
with
Pdffun.BadFunctionEvaluation s ->
raise (Pdf.PDFError ("Bad tint transform function " ^ s))
done;
s'
let rec read_raw_image size colspace bpc pdf resources width height dict data =
match size, colspace, bpc with
| size, (Pdfspace.DeviceRGB | Pdfspace.CalRGB _), Some (Pdf.Integer 8)
when size >= width * height * 3 ->
Raw (width, height, BPP24, data)
| size, Pdfspace.DeviceCMYK, Some (Pdf.Integer 8)
when size >= width * height * 4 ->
Raw (width, height, BPP24, read_cmyk_8bpp_as_rgb24 width height data)
| size, (Pdfspace.DeviceGray | Pdfspace.CalGray _), Some (Pdf.Integer 8)
when size >= width * height ->
Raw (width, height, BPP24, read_gray_8bpp_as_rgb24 width height data)
| size, _, Some (Pdf.Integer 1)
when size >= width * height / 8 ->
Raw (width, height, BPP24, read_1bpp_as_rgb24 width height data)
| size, Pdfspace.DeviceGray, Some (Pdf.Integer 4)
when size >= width * height / 2 ->
Raw (width, height, BPP24, read_4bpp_gray_as_rgb24 width height data)
| size, Pdfspace.Indexed ((Pdfspace.DeviceRGB | Pdfspace.CalRGB _), table), Some (Pdf.Integer 8)
| size,
Pdfspace.Indexed
((Pdfspace.DeviceN (_, (Pdfspace.DeviceRGB | Pdfspace.CalRGB _ |
Pdfspace.ICCBased {Pdfspace.icc_alternate = (Pdfspace.DeviceRGB |
Pdfspace.CalRGB _)}), _, _) |
Pdfspace.ICCBased {Pdfspace.icc_alternate = (Pdfspace.DeviceRGB |
Pdfspace.CalRGB _)}) , table),
Some (Pdf.Integer 8)
when size >= width * height ->
Raw (width, height, BPP24, read_8bpp_indexed_as_rgb24 table width height data)
| size, Pdfspace.Indexed (Pdfspace.DeviceCMYK, table), Some (Pdf.Integer 8)
when size >= width * height ->
Raw (width, height, BPP24, read_8bpp_cmyk_indexed_as_rgb24 table width height data)
| size, Pdfspace.Indexed ((Pdfspace.DeviceRGB | Pdfspace.CalRGB _), table), Some (Pdf.Integer 4)
| size, Pdfspace.Indexed (Pdfspace.ICCBased {Pdfspace.icc_alternate = (Pdfspace.DeviceRGB | Pdfspace.CalRGB _)}, table), Some (Pdf.Integer 4)
when size >= width * height / 2 ->
Raw (width, height, BPP24, read_4bpp_indexed_as_rgb24 table width height data)
| size, Pdfspace.Indexed ((Pdfspace.DeviceCMYK), table), Some (Pdf.Integer 4)
| size, Pdfspace.Indexed (Pdfspace.ICCBased {Pdfspace.icc_alternate = (Pdfspace.DeviceCMYK)}, table), Some (Pdf.Integer 4)
when size >= width * height / 2 ->
Raw (width, height, BPP24, read_4bpp_cmyk_indexed_as_rgb24 table width height data)
| size, Pdfspace.Indexed (Pdfspace.Lab (p, q, rs), table), Some (Pdf.Integer 8)
when size >= width * height / 2 ->
Raw (width, height, BPP24, read_8bpp_lab_indexed_as_rgb24 table width height p q rs data)
| size, Pdfspace.Separation (_, Pdfspace.DeviceCMYK, fn), Some (Pdf.Integer 8)
when size >= width * height ->
Raw (width, height, BPP24, read_separation_cmyk_as_rgb24 fn width height data)
| size, Pdfspace.ICCBased {Pdfspace.icc_alternate = cs}, _ ->
read_raw_image size cs bpc pdf resources width height dict data
| size, cs, bpc ->
(*i Printf.printf "NO IMAGE:\n size:%i\n cspace\n%s\n bpc\n%s\n width %i\n height %i\n" size
(Pdfspace.string_of_colourspace cs)
(match bpc with None -> "NONE" | Some bpc -> Pdfwrite.string_of_pdf bpc)
width
height;
flush stdout; i*)
raise (Pdf.PDFError "No image\n")
let get_raw_image pdf resources width height dict data =
try
let size =
bytes_size data
in let colspace =
(* If an image mask, it's /DeviceGray, effectively *)
match Pdf.lookup_direct_orelse pdf "/ImageMask" "/IM" dict with
| Some (Pdf.Boolean true) -> Pdfspace.DeviceGray
| _ ->
let colspace =
Pdf.lookup_direct_orelse pdf "/ColorSpace" "/CS" dict
in
let space =
match Pdf.lookup_direct pdf "/ColorSpace" resources, colspace with
| Some (Pdf.Dictionary _ as d), Some (Pdf.Name c) ->
begin match Pdf.lookup_direct pdf c d with
| Some colspace -> colspace
| _ -> (Pdf.Name c)
end
| _ ->
match colspace with
| Some c -> c
| _ -> raise (Pdf.PDFError "PDf image: no colourspace")
in
Pdfspace.read_colourspace pdf resources space
in let bpc =
match Pdf.lookup_direct_orelse pdf "/BitsPerComponent" "/BPC" dict with
| Some bpc -> Some bpc
| None ->
match Pdf.lookup_direct pdf "/ImageMask" dict with
| Some (Pdf.Boolean true) -> Some (Pdf.Integer 1)
| _ -> None
in
(*i flprint ("IMAGE SPACE:\n" ^ Pdfspace.string_of_colourspace colspace ^
* "\n"); i*)
read_raw_image size colspace bpc pdf resources width height dict data
with
e ->
(*i Printf.eprintf (Pdfwrite.string_of_pdf (Pdf.direct pdf dict)); i*)
raise e
(* Print some debug information about an image. *)
let print_image pdf resources img =
(*i Printf.printf "-----------------------------------------------------\n";
Printf.printf "Image Dictionary:\n%s\n" (Pdfwrite.string_of_pdf img); i*)
let w = match Pdf.lookup_direct pdf "/Width" img with Some (Pdf.Integer n) -> n | _ -> 0
in let h = match Pdf.lookup_direct pdf "/Height" img with Some (Pdf.Integer n)-> n | _ -> 0 in
Printf.printf "Width is %i, height %i\n" w h;
begin match Pdf.lookup_direct pdf "/ColorSpace" img with
| Some cs -> Printf.printf "Colourspace is...%s\n" (Pdfspace.string_of_colourspace (Pdfspace.read_colourspace pdf resources cs))
| None -> Printf.printf "No Colourspace\n"
end;
begin match Pdf.lookup_direct pdf "/BitsPerComponent" img with
| Some (Pdf.Integer n) -> Printf.printf "%i Bits Per Component\n" n
| _ -> Printf.printf "No /BitsPerComponent\n"
end;
begin match Pdf.lookup_direct pdf "/Decode" img with
| Some decode -> Printf.printf "Decode Array: %s\n" (Pdfwrite.string_of_pdf decode)
| None -> Printf.printf "No /Decode Array\n"
end
let get_image_24bpp pdf resources stream =
(*i flprint "\n";
print_image pdf resources (Pdf.direct pdf stream);
flprint "\n"; i*)
let stream = Pdf.direct pdf stream in
let streamdict, data =
Pdf.getstream stream;
match stream with
| Pdf.Stream {contents = (s, Pdf.Got d)} ->
s, d
| _ -> assert false (*r [Pdf.getstream] would have failed *)
in
let width =
match (Pdf.lookup_direct_orelse pdf "/Width" "/W" streamdict) with
| Some (Pdf.Integer x) -> x
| _ -> raise (Pdf.PDFError "Malformed /Image width")
in let height =
match (Pdf.lookup_direct_orelse pdf "/Height" "/H" streamdict) with
| Some (Pdf.Integer x) -> x
| _ -> raise (Pdf.PDFError "Malformed /Image height")
in let bpc =
match Pdf.lookup_direct_orelse pdf "/BitsPerComponent" "/BPC" streamdict with
| Some (Pdf.Integer n) -> n
| _ -> 0
in
decode_to_image pdf stream;
match stream with
| Pdf.Stream {contents = (Pdf.Dictionary d) as dict, Pdf.Got s} ->
let get_decode () =
let decode_entry = Pdf.lookup_direct_orelse pdf "/Decode" "/D" dict in
let decode_entry = decode_defaults pdf resources decode_entry dict in
match decode_entry with
| Some (Pdf.Array nums) ->
Some (map (function (Pdf.Real n) -> n | _ -> 0.) nums)
| _ -> None
in
begin match Pdf.lookup_direct_orelse pdf "/Filter" "/F" dict with
| None | Some (Pdf.Array []) ->
let raw = get_raw_image pdf resources width height dict s
in let decode_entry = Pdf.lookup_direct_orelse pdf "/Decode" "/D" dict in
(* Printf.printf "Decode entry before decode_defaults %s\n"
((function None -> "None" | Some x -> (Pdfwrite.string_of_pdf
x)) decode_entry); i*)
let decode_entry = decode_defaults pdf resources decode_entry dict in
(*i Printf.printf "Decode entry after decode_defaults %s\n"
((function None -> "None" | Some x -> (Pdfwrite.string_of_pdf
x)) decode_entry); i*)
let floats =
match decode_entry with
| Some (Pdf.Array elts) -> Array.of_list (map Pdf.getnum elts)
| None -> [||]
| _ -> raise (Pdf.PDFError "Bad /Decode")
in
begin match raw with
| Raw (_, _, _, data) -> if floats <> [||] then decode floats bpc data;
| _ -> ()
end;
raw
| Some (Pdf.Name ("/DCTDecode" | "/DCT"))
| Some (Pdf.Array [Pdf.Name ("/DCTDecode" | "/DCT")]) -> JPEG (s, get_decode ())
| Some (Pdf.Name "/JBIG2Decode")
| Some (Pdf.Array [Pdf.Name "/JBIG2Decode"]) -> JBIG2 (s, get_decode ())
| Some (Pdf.Name "/JPXDecode")
| Some (Pdf.Array [Pdf.Name "/JPXDecode"]) -> JPEG2000 (s, get_decode ())
| _ -> raise (Pdf.PDFError "decode_to_image")
end
| _ -> assert false
(* For now, this just knows how to do 1bpp specially, since this causes enormous
memory headaches in pdf2xar *)
let get_image pdf resources stream =
let stream = Pdf.direct pdf stream in
let streamdict, data =
Pdf.getstream stream;
match stream with
| Pdf.Stream {contents = (s, Pdf.Got d)} -> s, d
| _ -> assert false (*r [Pdf.getstream] would have failed *)
in
let components =
let colourspace =
match Pdf.lookup_direct_orelse pdf "/ColorSpace" "/CS" stream with
| None -> Pdf.Name "/DeviceGray" (* This is for image masks, in which the colourspace is implicitly 1 bpp *)
| Some x -> x
in
Pdfops.components pdf resources colourspace
and bpc =
match Pdf.lookup_direct_orelse pdf "/BitsPerComponent" "/BPC" streamdict
with
| Some (Pdf.Integer i) -> i
| _ -> raise (Pdf.PDFError "bad /BitsPerComponent")
and colorspace =
(* If an image mask, it's /DeviceGray, effectively *)
match Pdf.lookup_direct_orelse pdf "/ImageMask" "/IM" stream with
| Some (Pdf.Boolean true) -> Pdfspace.DeviceGray
| _ ->
let colspace =
Pdf.lookup_direct_orelse pdf "/ColorSpace" "/CS" stream
in
let space =
match Pdf.lookup_direct pdf "/ColorSpace" resources, colspace with
| Some (Pdf.Dictionary _ as d), Some (Pdf.Name c) ->
begin match Pdf.lookup_direct pdf c d with
| Some colspace -> colspace
| _ -> (Pdf.Name c)
end
| _ ->
match colspace with
| Some c -> c
| _ -> raise (Pdf.PDFError "PDf image: no colourspace")
in
Pdfspace.read_colourspace pdf resources space
in
(*i Printf.printf "get_image: %i components, %i bits per component\n" components bpc;
Printf.printf "colorspace is %s\n" (Pdfspace.string_of_colourspace
colorspace); i*)
match bpc, components, colorspace with
| (8 | 1), 1, (Pdfspace.DeviceGray | Pdfspace.DeviceRGB | Pdfspace.CalGray _ | Pdfspace.CalRGB _) ->
(* 1bpp black and white and 8bpp greyscale special case *)
begin
let width =
match (Pdf.lookup_direct_orelse pdf "/Width" "/W" streamdict) with
| Some (Pdf.Integer x) -> x
| _ -> raise (Pdf.PDFError "Malformed /Image width")
and height =
match (Pdf.lookup_direct_orelse pdf "/Height" "/H" streamdict) with
| Some (Pdf.Integer x) -> x
| _ -> raise (Pdf.PDFError "Malformed /Image height")
in
decode_to_image pdf stream;
begin match stream with
| Pdf.Stream {contents = (Pdf.Dictionary d) as dict, Pdf.Got s} ->
let get_decode () =
let decode_entry = Pdf.lookup_direct_orelse pdf "/Decode" "/D" dict in
let decode_entry = decode_defaults pdf resources decode_entry dict in
match decode_entry with
| Some (Pdf.Array nums) ->
Some (map (function Pdf.Real n -> n | Pdf.Integer i -> float i | _ -> 0.) nums)
| _ -> None
in
begin match Pdf.lookup_direct_orelse pdf "/Filter" "/F" dict with
| None | Some (Pdf.Array []) ->
(* Now, fetch the raw data from the stream and, if necessary.
apply the decode... *)
let s =
if get_decode () = Some [1.; 0.] then
let s = copybytes s in
bytes_selfmap (if bpc = 1 then lnot else (function x -> 255 - x)) s;
s
else
s
in
Raw (width, height, (if bpc = 1 then BPP1 else BPP8), s)
| Some (Pdf.Name ("/DCTDecode" | "/DCT"))
| Some (Pdf.Array [Pdf.Name ("/DCTDecode" | "/DCT")]) -> JPEG (s, get_decode ())
| Some (Pdf.Name "/JBIG2Decode")
| Some (Pdf.Array [Pdf.Name "/JBIG2Decode"]) -> JBIG2 (s, get_decode ())
| Some (Pdf.Name "/JPXDecode")
| Some (Pdf.Array [Pdf.Name "/JPXDecode"]) -> JPEG2000 (s, get_decode ())
| _ -> raise (Pdf.PDFError "decode_to_image")
end
| _ -> raise (Pdf.PDFError "get_image")
end
end
| _ -> get_image_24bpp pdf resources stream
let get_image_raw_24bpp (pdf : Pdf.t) (resources : Pdf.pdfobject) (stream : Pdf.pdfobject) =
(raise (Pdf.PDFError "get_image not implemented") : t)
let get_image_raw (pdf : Pdf.t) (resources : Pdf.pdfobject) (stream : Pdf.pdfobject) =
(raise (Pdf.PDFError "get_image not implemented") : t)
(** Return a function which, when given an x and y coordinate, returns the pixel
byte values prior to any decoding, i.e in the raw input image data before /Decode,
/Index lookups and so on. Returns array of components as bytes.
This function is needed because color key masking is defined in terms of the
pixel values of undecoded images. *)
let get_image_unprocessed_pixel pdf resources stream =
(* 1. Need to getstream / uncompress the image as normal (including any
predictor), if not already done. *)
Pdf.getstream stream;
decode_to_image pdf stream;
(* 1A. If it's JPEG, we can't oblige - Need a JPEG decoder to fix this... *)
match stream with
| Pdf.Stream {contents = d, Pdf.Got data} ->
begin match Pdf.lookup_direct pdf "/Filter" d with
| Some (Pdf.Name ("/DCTDecode" | "/DCT" | "/JBIG2Decode" | "/JPXDecode"))
| Some (Pdf.Array [Pdf.Name ("/DCTDecode" | "/DCT" | "/JBIG2Decode" | "/JPXDecode")]) -> None
| _ ->
(* 2. Now, work out how many bytes per pixel - check this *)
let bpc =
match Pdf.lookup_direct_orelse pdf "/BitsPerComponent" "/BPC" stream with
| Some (Pdf.Integer n) -> n
| _ -> 0
in let nocomponents =
let colourspace =
match Pdf.lookup_direct pdf "/ColorSpace" stream with
| None -> Pdf.Dictionary []
| Some x -> x
in
Pdfops.components pdf resources colourspace
in
if bpc <> 8 then None else (* FIXME: Things other than bytes *)
(* 3. Return the function, and making sure enough data / error handling done properly. *)
Some
(fun s ->
try
(* Get nocomponents from correct position in data and put in an array... *)
let pos =
s * nocomponents
in
let a = Array.make nocomponents 0 in
for x = 0 to nocomponents - 1 do
a.(x) <- bget data (pos + x)
done;
a
with
_ -> raise (Pdf.PDFError "bad serial in get_image_unprocessed_pixel"))
end
| _ -> None
|