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GeezerVison is showing github.com — matplotlib/src/_png.cpp at master · feisuo/matplotlib Expand file tree/ Copy path_png.cppMore file actions 703 lines (604 loc) · 20 KB / Copy path_png.cppFile metadata and controls703 lines (604 loc) · 20 KB 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 /* -*- mode: c++; c-basic-offset: 4 -*- */ // this code is heavily adapted from the paint license, which is in // the file paint.license (BSD compatible) included in this // distribution. TODO, add license file to MANIFEST.in and CVS /* For linux, png.h must be imported before Python.h because png.h needs to be the one to define setjmp. Undefining _POSIX_C_SOURCE and _XOPEN_SOURCE stops a couple of harmless warnings. */ extern "C" { # include <png.h> # ifdef _POSIX_C_SOURCE # undef _POSIX_C_SOURCE # endif # ifdef _XOPEN_SOURCE # undef _XOPEN_SOURCE # endif } #include "numpy_cpp.h" #include "mplutils.h" #include "file_compat.h" # include <vector> # include "Python.h" // As reported in [3082058] build _png.so on aix #ifdef _AIX #undef jmpbuf #endif struct buffer_t { PyObject *str; size_t cursor; size_t size; }; static void write_png_data_buffer(png_structp png_ptr, png_bytep data, png_size_t length) { buffer_t *buff = (buffer_t *)png_get_io_ptr(png_ptr); if (buff->cursor + length < buff->size) { memcpy(PyBytes_AS_STRING(buff->str) + buff->cursor, data, length); buff->cursor += length; } } static void flush_png_data_buffer(png_structp png_ptr) { } static void write_png_data(png_structp png_ptr, png_bytep data, png_size_t length) { PyObject *py_file_obj = (PyObject *)png_get_io_ptr(png_ptr); PyObject *write_method = PyObject_GetAttrString(py_file_obj, "write"); PyObject *result = NULL; if (write_method) { #if PY3K result = PyObject_CallFunction(write_method, (char *)"y#", data, length); #else result = PyObject_CallFunction(write_method, (char *)"s#", data, length); #endif } Py_XDECREF(write_method); Py_XDECREF(result); } static void flush_png_data(png_structp png_ptr) { PyObject *py_file_obj = (PyObject *)png_get_io_ptr(png_ptr); PyObject *flush_method = PyObject_GetAttrString(py_file_obj, "flush"); PyObject *result = NULL; if (flush_method) { result = PyObject_CallFunction(flush_method, (char *)""); } Py_XDECREF(flush_method); Py_XDECREF(result); } const char *Py_write_png__doc__ = "write_png(buffer, file, dpi=0, compression=6, filter=auto)\n" "\n" "Parameters\n" "----------\n" "buffer : numpy array of image data\n" " Must be an MxNxD array of dtype uint8.\n" " - if D is 1, the image is greyscale\n" " - if D is 3, the image is RGB\n" " - if D is 4, the image is RGBA\n" "\n" "file : str path, file-like object or None\n" " - If a str, must be a file path\n" " - If a file-like object, must write bytes\n" " - If None, a byte string containing the PNG data will be returned\n" "\n" "dpi : float\n" " The dpi to store in the file metadata.\n" "\n" "compression : int\n" " The level of lossless zlib compression to apply. 0 indicates no\n" " compression. Values 1-9 indicate low/fast through high/slow\n" " compression. Default is 6.\n" "\n" "filter : int\n" " Filter to apply. Must be one of the constants: PNG_FILTER_NONE,\n" " PNG_FILTER_SUB, PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH.\n" " See the PNG standard for more information.\n" " If not provided, libpng will try to automatically determine the\n" " best filter on a line-by-line basis.\n" "\n" "Returns\n" "-------\n" "buffer : bytes or None\n" " Byte string containing the PNG content if None was passed in for\n" " file, otherwise None is returned.\n"; static PyObject *Py_write_png(PyObject *self, PyObject *args, PyObject *kwds) { numpy::array_view<unsigned char, 3> buffer; PyObject *filein; double dpi = 0; int compression = 6; int filter = -1; const char *names[] = { "buffer", "file", "dpi", "compression", "filter", NULL }; // We don't need strict contiguity, just for each row to be // contiguous, and libpng has special handling for getting RGB out // of RGBA, ARGB or BGR. But the simplest thing to do is to // enforce contiguity using array_view::converter_contiguous. if (!PyArg_ParseTupleAndKeywords(args, kwds, "O&O|dii:write_png", (char **)names, &buffer.converter_contiguous, &buffer, &filein, &dpi, &compression, &filter)) { return NULL; } png_uint_32 width = (png_uint_32)buffer.dim(1); png_uint_32 height = (png_uint_32)buffer.dim(0); int channels = buffer.dim(2); std::vector<png_bytep> row_pointers(height); for (png_uint_32 row = 0; row < (png_uint_32)height; ++row) { row_pointers[row] = (png_bytep)&buffer(row, 0, 0); } FILE *fp = NULL; mpl_off_t offset = 0; bool close_file = false; bool close_dup_file = false; PyObject *py_file = NULL; png_structp png_ptr = NULL; png_infop info_ptr = NULL; struct png_color_8_struct sig_bit; int png_color_type; buffer_t buff; buff.str = NULL; switch (channels) { case 1: png_color_type = PNG_COLOR_TYPE_GRAY; break; case 3: png_color_type = PNG_COLOR_TYPE_RGB; break; case 4: png_color_type = PNG_COLOR_TYPE_RGB_ALPHA; break; default: PyErr_SetString(PyExc_ValueError, "Buffer must be an NxMxD array with D in 1, 3, 4 " "(grayscale, RGB, RGBA)"); goto exit; } if (compression < 0 || compression > 9) { PyErr_Format(PyExc_ValueError, "compression must be in range 0-9, got %d", compression); goto exit; } if (PyBytes_Check(filein) || PyUnicode_Check(filein)) { if ((py_file = mpl_PyFile_OpenFile(filein, (char *)"wb")) == NULL) { goto exit; } close_file = true; } else { py_file = filein; } if (filein == Py_None) { buff.size = width * height * 4 + 1024; buff.str = PyBytes_FromStringAndSize(NULL, buff.size); if (buff.str == NULL) { goto exit; } buff.cursor = 0; } else { #if PY3K if (close_file) { #else if (close_file || PyFile_Check(py_file)) { #endif fp = mpl_PyFile_Dup(py_file, (char *)"wb", &offset); } if (fp) { close_dup_file = true; } else { PyErr_Clear(); PyObject *write_method = PyObject_GetAttrString(py_file, "write"); if (!(write_method && PyCallable_Check(write_method))) { Py_XDECREF(write_method); PyErr_SetString(PyExc_TypeError, "Object does not appear to be a 8-bit string path or " "a Python file-like object"); goto exit; } Py_XDECREF(write_method); } } png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (png_ptr == NULL) { PyErr_SetString(PyExc_RuntimeError, "Could not create write struct"); goto exit; } png_set_compression_level(png_ptr, compression); if (filter >= 0) { png_set_filter(png_ptr, 0, filter); } info_ptr = png_create_info_struct(png_ptr); if (info_ptr == NULL) { PyErr_SetString(PyExc_RuntimeError, "Could not create info struct"); goto exit; } if (setjmp(png_jmpbuf(png_ptr))) { PyErr_SetString(PyExc_RuntimeError, "libpng signaled error"); goto exit; } if (buff.str) { png_set_write_fn(png_ptr, (void *)&buff, &write_png_data_buffer, &flush_png_data_buffer); } else if (fp) { png_init_io(png_ptr, fp); } else { png_set_write_fn(png_ptr, (void *)py_file, &write_png_data, &flush_png_data); } png_set_IHDR(png_ptr, info_ptr, width, height, 8, png_color_type, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); // Save the dpi of the image in the file if (dpi > 0.0) { png_uint_32 dots_per_meter = (png_uint_32)(dpi / (2.54 / 100.0)); png_set_pHYs(png_ptr, info_ptr, dots_per_meter, dots_per_meter, PNG_RESOLUTION_METER); } sig_bit.alpha = 0; switch (png_color_type) { case PNG_COLOR_TYPE_GRAY: sig_bit.gray = 8; sig_bit.red = 0; sig_bit.green = 0; sig_bit.blue = 0; break; case PNG_COLOR_TYPE_RGB_ALPHA: sig_bit.alpha = 8; // fall through case PNG_COLOR_TYPE_RGB: sig_bit.gray = 0; sig_bit.red = 8; sig_bit.green = 8; sig_bit.blue = 8; break; default: PyErr_SetString(PyExc_RuntimeError, "internal error, bad png_color_type"); goto exit; } png_set_sBIT(png_ptr, info_ptr, &sig_bit); png_write_info(png_ptr, info_ptr); png_write_image(png_ptr, &row_pointers[0]); png_write_end(png_ptr, info_ptr); exit: if (png_ptr && info_ptr) { png_destroy_write_struct(&png_ptr, &info_ptr); } if (close_dup_file) { mpl_PyFile_DupClose(py_file, fp, offset); } if (close_file) { mpl_PyFile_CloseFile(py_file); Py_DECREF(py_file); } if (PyErr_Occurred()) { Py_XDECREF(buff.str); return NULL; } else { if (buff.str) { _PyBytes_Resize(&buff.str, buff.cursor); return buff.str; } Py_RETURN_NONE; } } static void _read_png_data(PyObject *py_file_obj, png_bytep data, png_size_t length) { PyObject *read_method = PyObject_GetAttrString(py_file_obj, "read"); PyObject *result = NULL; char *buffer; Py_ssize_t bufflen; if (read_method) { result = PyObject_CallFunction(read_method, (char *)"i", length); if (PyBytes_AsStringAndSize(result, &buffer, &bufflen) == 0) { if (bufflen == (Py_ssize_t)length) { memcpy(data, buffer, length); } else { PyErr_SetString(PyExc_IOError, "read past end of file"); } } } Py_XDECREF(read_method); Py_XDECREF(result); } static void read_png_data(png_structp png_ptr, png_bytep data, png_size_t length) { PyObject *py_file_obj = (PyObject *)png_get_io_ptr(png_ptr); _read_png_data(py_file_obj, data, length); } static PyObject *_read_png(PyObject *filein, bool float_result) { png_byte header[8]; // 8 is the maximum size that can be checked FILE *fp = NULL; mpl_off_t offset = 0; bool close_file = false; bool close_dup_file = false; PyObject *py_file = NULL; png_structp png_ptr = NULL; png_infop info_ptr = NULL; int num_dims; std::vector<png_bytep> row_pointers; png_uint_32 width = 0; png_uint_32 height = 0; int bit_depth; PyObject *result = NULL; // TODO: Remove direct calls to Numpy API here if (PyBytes_Check(filein) || PyUnicode_Check(filein)) { if ((py_file = mpl_PyFile_OpenFile(filein, (char *)"rb")) == NULL) { goto exit; } close_file = true; } else { py_file = filein; } #if PY3K if (close_file) { #else if (close_file || PyFile_Check(py_file)) { #endif fp = mpl_PyFile_Dup(py_file, (char *)"rb", &offset); } if (fp) { close_dup_file = true; if (fread(header, 1, 8, fp) != 8) { PyErr_SetString(PyExc_IOError, "error reading PNG header"); goto exit; } } else { PyErr_Clear(); PyObject *read_method = PyObject_GetAttrString(py_file, "read"); if (!(read_method && PyCallable_Check(read_method))) { Py_XDECREF(read_method); PyErr_SetString(PyExc_TypeError, "Object does not appear to be a 8-bit string path or " "a Python file-like object"); goto exit; } Py_XDECREF(read_method); _read_png_data(py_file, header, 8); } if (png_sig_cmp(header, 0, 8)) { PyErr_SetString(PyExc_ValueError, "invalid PNG header"); goto exit; } /* initialize stuff */ png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (!png_ptr) { PyErr_SetString(PyExc_RuntimeError, "png_create_read_struct failed"); goto exit; } info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { PyErr_SetString(PyExc_RuntimeError, "png_create_info_struct failed"); goto exit; } if (setjmp(png_jmpbuf(png_ptr))) { PyErr_SetString(PyExc_RuntimeError, "Error setting jump"); goto exit; } if (fp) { png_init_io(png_ptr, fp); } else { png_set_read_fn(png_ptr, (void *)py_file, &read_png_data); } png_set_sig_bytes(png_ptr, 8); png_read_info(png_ptr, info_ptr); width = png_get_image_width(png_ptr, info_ptr); height = png_get_image_height(png_ptr, info_ptr); bit_depth = png_get_bit_depth(png_ptr, info_ptr); // Unpack 1, 2, and 4-bit images if (bit_depth < 8) { png_set_packing(png_ptr); } // If sig bits are set, shift data png_color_8p sig_bit; if ((png_get_color_type(png_ptr, info_ptr) != PNG_COLOR_TYPE_PALETTE) && png_get_sBIT(png_ptr, info_ptr, &sig_bit)) { png_set_shift(png_ptr, sig_bit); } // Convert big endian to little if (bit_depth == 16) { png_set_swap(png_ptr); } // Convert palletes to full RGB if (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_PALETTE) { png_set_palette_to_rgb(png_ptr); bit_depth = 8; } // If there's an alpha channel convert gray to RGB if (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_GRAY_ALPHA) { png_set_gray_to_rgb(png_ptr); } png_set_interlace_handling(png_ptr); png_read_update_info(png_ptr, info_ptr); row_pointers.resize(height); for (png_uint_32 row = 0; row < height; row++) { row_pointers[row] = new png_byte[png_get_rowbytes(png_ptr, info_ptr)]; } png_read_image(png_ptr, &row_pointers[0]); npy_intp dimensions[3]; dimensions[0] = height; // numrows dimensions[1] = width; // numcols if (png_get_color_type(png_ptr, info_ptr) & PNG_COLOR_MASK_ALPHA) { dimensions[2] = 4; // RGBA images } else if (png_get_color_type(png_ptr, info_ptr) & PNG_COLOR_MASK_COLOR) { dimensions[2] = 3; // RGB images } else { dimensions[2] = 1; // Greyscale images } if (float_result) { double max_value = (1 << bit_depth) - 1; numpy::array_view<float, 3> A(dimensions); for (png_uint_32 y = 0; y < height; y++) { png_byte *row = row_pointers[y]; for (png_uint_32 x = 0; x < width; x++) { if (bit_depth == 16) { png_uint_16 *ptr = &reinterpret_cast<png_uint_16 *>(row)[x * dimensions[2]]; for (png_uint_32 p = 0; p < (png_uint_32)dimensions[2]; p++) { A(y, x, p) = (float)(ptr[p]) / max_value; } } else { png_byte *ptr = &(row[x * dimensions[2]]); for (png_uint_32 p = 0; p < (png_uint_32)dimensions[2]; p++) { A(y, x, p) = (float)(ptr[p]) / max_value; } } } } result = A.pyobj(); } else if (bit_depth == 16) { numpy::array_view<png_uint_16, 3> A(dimensions); for (png_uint_32 y = 0; y < height; y++) { png_byte *row = row_pointers[y]; for (png_uint_32 x = 0; x < width; x++) { png_uint_16 *ptr = &reinterpret_cast<png_uint_16 *>(row)[x * dimensions[2]]; for (png_uint_32 p = 0; p < (png_uint_32)dimensions[2]; p++) { A(y, x, p) = ptr[p]; } } } result = A.pyobj(); } else if (bit_depth == 8) { numpy::array_view<png_byte, 3> A(dimensions); for (png_uint_32 y = 0; y < height; y++) { png_byte *row = row_pointers[y]; for (png_uint_32 x = 0; x < width; x++) { png_byte *ptr = &(row[x * dimensions[2]]); for (png_uint_32 p = 0; p < (png_uint_32)dimensions[2]; p++) { A(y, x, p) = ptr[p]; } } } result = A.pyobj(); } else { PyErr_SetString(PyExc_RuntimeError, "image has unknown bit depth"); goto exit; } // free the png memory png_read_end(png_ptr, info_ptr); // For gray, return an x by y array, not an x by y by 1 num_dims = (png_get_color_type(png_ptr, info_ptr) & PNG_COLOR_MASK_COLOR) ? 3 : 2; if (num_dims == 2) { PyArray_Dims dims = {dimensions, 2}; PyObject *reshaped = PyArray_Newshape((PyArrayObject *)result, &dims, NPY_CORDER); Py_DECREF(result); result = reshaped; } exit: if (png_ptr && info_ptr) { #ifndef png_infopp_NULL png_destroy_read_struct(&png_ptr, &info_ptr, NULL); #else png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL); #endif } if (close_dup_file) { mpl_PyFile_DupClose(py_file, fp, offset); } if (close_file) { mpl_PyFile_CloseFile(py_file); Py_DECREF(py_file); } for (png_uint_32 row = 0; row < height; row++) { delete[] row_pointers[row]; } if (PyErr_Occurred()) { Py_XDECREF(result); return NULL; } else { return result; } } const char *Py_read_png_float__doc__ = "read_png_float(file)\n" "\n" "Read in a PNG file, converting values to floating-point doubles\n" "in the range (0, 1)\n" "\n" "Parameters\n" "----------\n" "file : str path or file-like object\n"; static PyObject *Py_read_png_float(PyObject *self, PyObject *args, PyObject *kwds) { return _read_png(args, true); } const char *Py_read_png_int__doc__ = "read_png_int(file)\n" "\n" "Read in a PNG file with original integer values.\n" "\n" "Parameters\n" "----------\n" "file : str path or file-like object\n"; static PyObject *Py_read_png_int(PyObject *self, PyObject *args, PyObject *kwds) { return _read_png(args, false); } const char *Py_read_png__doc__ = "read_png(file)\n" "\n" "Read in a PNG file, converting values to floating-point doubles\n" "in the range (0, 1)\n" "\n" "Alias for read_png_float()\n" "\n" "Parameters\n" "----------\n" "file : str path or file-like object\n"; static PyMethodDef module_methods[] = { {"write_png", (PyCFunction)Py_write_png, METH_VARARGS|METH_KEYWORDS, Py_write_png__doc__}, {"read_png", (PyCFunction)Py_read_png_float, METH_O, Py_read_png__doc__}, {"read_png_float", (PyCFunction)Py_read_png_float, METH_O, Py_read_png_float__doc__}, {"read_png_int", (PyCFunction)Py_read_png_int, METH_O, Py_read_png_int__doc__}, {NULL} }; extern "C" { #if PY3K static struct PyModuleDef moduledef = { PyModuleDef_HEAD_INIT, "_png", NULL, 0, module_methods, NULL, NULL, NULL, NULL }; #define INITERROR return NULL PyMODINIT_FUNC PyInit__png(void) #else #define INITERROR return PyMODINIT_FUNC init_png(void) #endif { PyObject *m; #if PY3K m = PyModule_Create(&moduledef); #else m = Py_InitModule3("_png", module_methods, NULL); #endif if (m == NULL) { INITERROR; } import_array(); if (PyModule_AddIntConstant(m, "PNG_FILTER_NONE", PNG_FILTER_NONE) || PyModule_AddIntConstant(m, "PNG_FILTER_SUB", PNG_FILTER_SUB) || PyModule_AddIntConstant(m, "PNG_FILTER_UP", PNG_FILTER_UP) || PyModule_AddIntConstant(m, "PNG_FILTER_AVG", PNG_FILTER_AVG) || PyModule_AddIntConstant(m, "PNG_FILTER_PAETH", PNG_FILTER_PAETH)) { INITERROR; } #if PY3K return m; #endif } } |
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