1 /* 2 * Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.imageio.plugins.png; 27 28 import java.awt.Point; 29 import java.awt.Rectangle; 30 import java.awt.color.ColorSpace; 31 import java.awt.image.BufferedImage; 32 import java.awt.image.DataBuffer; 33 import java.awt.image.DataBufferByte; 34 import java.awt.image.DataBufferUShort; 35 import java.awt.image.Raster; 36 import java.awt.image.WritableRaster; 37 import java.io.BufferedInputStream; 38 import java.io.ByteArrayInputStream; 39 import java.io.DataInputStream; 40 import java.io.EOFException; 41 import java.io.InputStream; 42 import java.io.IOException; 43 import java.io.SequenceInputStream; 44 import java.util.ArrayList; 45 import java.util.Arrays; 46 import java.util.Enumeration; 47 import java.util.Iterator; 48 import java.util.zip.Inflater; 49 import java.util.zip.InflaterInputStream; 50 import javax.imageio.IIOException; 51 import javax.imageio.ImageReader; 52 import javax.imageio.ImageReadParam; 53 import javax.imageio.ImageTypeSpecifier; 54 import javax.imageio.metadata.IIOMetadata; 55 import javax.imageio.spi.ImageReaderSpi; 56 import javax.imageio.stream.ImageInputStream; 57 import com.sun.imageio.plugins.common.InputStreamAdapter; 58 import com.sun.imageio.plugins.common.ReaderUtil; 59 import com.sun.imageio.plugins.common.SubImageInputStream; 60 import java.io.ByteArrayOutputStream; 61 import sun.awt.image.ByteInterleavedRaster; 62 63 class PNGImageDataEnumeration implements Enumeration<InputStream> { 64 65 boolean firstTime = true; 66 ImageInputStream stream; 67 int length; 68 69 public PNGImageDataEnumeration(ImageInputStream stream) 70 throws IOException { 71 this.stream = stream; 72 this.length = stream.readInt(); 73 int type = stream.readInt(); // skip chunk type 74 } 75 76 public InputStream nextElement() { 77 try { 78 firstTime = false; 79 ImageInputStream iis = new SubImageInputStream(stream, length); 80 return new InputStreamAdapter(iis); 81 } catch (IOException e) { 82 return null; 83 } 84 } 85 86 public boolean hasMoreElements() { 87 if (firstTime) { 88 return true; 89 } 90 91 try { 92 int crc = stream.readInt(); 93 this.length = stream.readInt(); 94 int type = stream.readInt(); 95 if (type == PNGImageReader.IDAT_TYPE) { 96 return true; 97 } else { 98 return false; 99 } 100 } catch (IOException e) { 101 return false; 102 } 103 } 104 } 105 106 public class PNGImageReader extends ImageReader { 107 108 /* 109 * Note: The following chunk type constants are autogenerated. Each 110 * one is derived from the ASCII values of its 4-character name. For 111 * example, IHDR_TYPE is calculated as follows: 112 * ('I' << 24) | ('H' << 16) | ('D' << 8) | 'R' 113 */ 114 115 // Critical chunks 116 static final int IHDR_TYPE = 0x49484452; 117 static final int PLTE_TYPE = 0x504c5445; 118 static final int IDAT_TYPE = 0x49444154; 119 static final int IEND_TYPE = 0x49454e44; 120 121 // Ancillary chunks 122 static final int bKGD_TYPE = 0x624b4744; 123 static final int cHRM_TYPE = 0x6348524d; 124 static final int gAMA_TYPE = 0x67414d41; 125 static final int hIST_TYPE = 0x68495354; 126 static final int iCCP_TYPE = 0x69434350; 127 static final int iTXt_TYPE = 0x69545874; 128 static final int pHYs_TYPE = 0x70485973; 129 static final int sBIT_TYPE = 0x73424954; 130 static final int sPLT_TYPE = 0x73504c54; 131 static final int sRGB_TYPE = 0x73524742; 132 static final int tEXt_TYPE = 0x74455874; 133 static final int tIME_TYPE = 0x74494d45; 134 static final int tRNS_TYPE = 0x74524e53; 135 static final int zTXt_TYPE = 0x7a545874; 136 137 static final int PNG_COLOR_GRAY = 0; 138 static final int PNG_COLOR_RGB = 2; 139 static final int PNG_COLOR_PALETTE = 3; 140 static final int PNG_COLOR_GRAY_ALPHA = 4; 141 static final int PNG_COLOR_RGB_ALPHA = 6; 142 143 // The number of bands by PNG color type 144 static final int[] inputBandsForColorType = { 145 1, // gray 146 -1, // unused 147 3, // rgb 148 1, // palette 149 2, // gray + alpha 150 -1, // unused 151 4 // rgb + alpha 152 }; 153 154 static final int PNG_FILTER_NONE = 0; 155 static final int PNG_FILTER_SUB = 1; 156 static final int PNG_FILTER_UP = 2; 157 static final int PNG_FILTER_AVERAGE = 3; 158 static final int PNG_FILTER_PAETH = 4; 159 160 static final int[] adam7XOffset = { 0, 4, 0, 2, 0, 1, 0 }; 161 static final int[] adam7YOffset = { 0, 0, 4, 0, 2, 0, 1 }; 162 static final int[] adam7XSubsampling = { 8, 8, 4, 4, 2, 2, 1, 1 }; 163 static final int[] adam7YSubsampling = { 8, 8, 8, 4, 4, 2, 2, 1 }; 164 165 private static final boolean debug = true; 166 167 ImageInputStream stream = null; 168 169 boolean gotHeader = false; 170 boolean gotMetadata = false; 171 172 ImageReadParam lastParam = null; 173 174 long imageStartPosition = -1L; 175 176 Rectangle sourceRegion = null; 177 int sourceXSubsampling = -1; 178 int sourceYSubsampling = -1; 179 int sourceMinProgressivePass = 0; 180 int sourceMaxProgressivePass = 6; 181 int[] sourceBands = null; 182 int[] destinationBands = null; 183 Point destinationOffset = new Point(0, 0); 184 185 PNGMetadata metadata = new PNGMetadata(); 186 187 DataInputStream pixelStream = null; 188 189 BufferedImage theImage = null; 190 191 // The number of source pixels processed 192 int pixelsDone = 0; 193 194 // The total number of pixels in the source image 195 int totalPixels; 196 197 public PNGImageReader(ImageReaderSpi originatingProvider) { 198 super(originatingProvider); 199 } 200 201 public void setInput(Object input, 202 boolean seekForwardOnly, 203 boolean ignoreMetadata) { 204 super.setInput(input, seekForwardOnly, ignoreMetadata); 205 this.stream = (ImageInputStream)input; // Always works 206 207 // Clear all values based on the previous stream contents 208 resetStreamSettings(); 209 } 210 211 private String readNullTerminatedString(String charset, int maxLen) throws IOException { 212 ByteArrayOutputStream baos = new ByteArrayOutputStream(); 213 int b = 0; 214 int count = 0; 215 while ((maxLen > count++) && ((b = stream.read()) != 0)) { 216 if (b == -1) throw new EOFException(); 217 baos.write(b); 218 } 219 if (b != 0) { 220 throw new IIOException("Found non null terminated string"); 221 } 222 return new String(baos.toByteArray(), charset); 223 } 224 225 private void readHeader() throws IIOException { 226 if (gotHeader) { 227 return; 228 } 229 if (stream == null) { 230 throw new IllegalStateException("Input source not set!"); 231 } 232 233 try { 234 byte[] signature = new byte[8]; 235 stream.readFully(signature); 236 237 if (signature[0] != (byte)137 || 238 signature[1] != (byte)80 || 239 signature[2] != (byte)78 || 240 signature[3] != (byte)71 || 241 signature[4] != (byte)13 || 242 signature[5] != (byte)10 || 243 signature[6] != (byte)26 || 244 signature[7] != (byte)10) { 245 throw new IIOException("Bad PNG signature!"); 246 } 247 248 int IHDR_length = stream.readInt(); 249 if (IHDR_length != 13) { 250 throw new IIOException("Bad length for IHDR chunk!"); 251 } 252 int IHDR_type = stream.readInt(); 253 if (IHDR_type != IHDR_TYPE) { 254 throw new IIOException("Bad type for IHDR chunk!"); 255 } 256 257 this.metadata = new PNGMetadata(); 258 259 int width = stream.readInt(); 260 int height = stream.readInt(); 261 262 // Re-use signature array to bulk-read these unsigned byte values 263 stream.readFully(signature, 0, 5); 264 int bitDepth = signature[0] & 0xff; 265 int colorType = signature[1] & 0xff; 266 int compressionMethod = signature[2] & 0xff; 267 int filterMethod = signature[3] & 0xff; 268 int interlaceMethod = signature[4] & 0xff; 269 270 // Skip IHDR CRC 271 stream.skipBytes(4); 272 273 stream.flushBefore(stream.getStreamPosition()); 274 275 if (width <= 0) { 276 throw new IIOException("Image width <= 0!"); 277 } 278 if (height <= 0) { 279 throw new IIOException("Image height <= 0!"); 280 } 281 if (bitDepth != 1 && bitDepth != 2 && bitDepth != 4 && 282 bitDepth != 8 && bitDepth != 16) { 283 throw new IIOException("Bit depth must be 1, 2, 4, 8, or 16!"); 284 } 285 if (colorType != 0 && colorType != 2 && colorType != 3 && 286 colorType != 4 && colorType != 6) { 287 throw new IIOException("Color type must be 0, 2, 3, 4, or 6!"); 288 } 289 if (colorType == PNG_COLOR_PALETTE && bitDepth == 16) { 290 throw new IIOException("Bad color type/bit depth combination!"); 291 } 292 if ((colorType == PNG_COLOR_RGB || 293 colorType == PNG_COLOR_RGB_ALPHA || 294 colorType == PNG_COLOR_GRAY_ALPHA) && 295 (bitDepth != 8 && bitDepth != 16)) { 296 throw new IIOException("Bad color type/bit depth combination!"); 297 } 298 if (compressionMethod != 0) { 299 throw new IIOException("Unknown compression method (not 0)!"); 300 } 301 if (filterMethod != 0) { 302 throw new IIOException("Unknown filter method (not 0)!"); 303 } 304 if (interlaceMethod != 0 && interlaceMethod != 1) { 305 throw new IIOException("Unknown interlace method (not 0 or 1)!"); 306 } 307 308 metadata.IHDR_present = true; 309 metadata.IHDR_width = width; 310 metadata.IHDR_height = height; 311 metadata.IHDR_bitDepth = bitDepth; 312 metadata.IHDR_colorType = colorType; 313 metadata.IHDR_compressionMethod = compressionMethod; 314 metadata.IHDR_filterMethod = filterMethod; 315 metadata.IHDR_interlaceMethod = interlaceMethod; 316 gotHeader = true; 317 } catch (IOException e) { 318 throw new IIOException("I/O error reading PNG header!", e); 319 } 320 } 321 322 private void parse_PLTE_chunk(int chunkLength) throws IOException { 323 if (metadata.PLTE_present) { 324 processWarningOccurred( 325 "A PNG image may not contain more than one PLTE chunk.\n" + 326 "The chunk wil be ignored."); 327 return; 328 } else if (metadata.IHDR_colorType == PNG_COLOR_GRAY || 329 metadata.IHDR_colorType == PNG_COLOR_GRAY_ALPHA) { 330 processWarningOccurred( 331 "A PNG gray or gray alpha image cannot have a PLTE chunk.\n" + 332 "The chunk wil be ignored."); 333 return; 334 } 335 336 byte[] palette = new byte[chunkLength]; 337 stream.readFully(palette); 338 339 int numEntries = chunkLength/3; 340 if (metadata.IHDR_colorType == PNG_COLOR_PALETTE) { 341 int maxEntries = 1 << metadata.IHDR_bitDepth; 342 if (numEntries > maxEntries) { 343 processWarningOccurred( 344 "PLTE chunk contains too many entries for bit depth, ignoring extras."); 345 numEntries = maxEntries; 346 } 347 numEntries = Math.min(numEntries, maxEntries); 348 } 349 350 // Round array sizes up to 2^2^n 351 int paletteEntries; 352 if (numEntries > 16) { 353 paletteEntries = 256; 354 } else if (numEntries > 4) { 355 paletteEntries = 16; 356 } else if (numEntries > 2) { 357 paletteEntries = 4; 358 } else { 359 paletteEntries = 2; 360 } 361 362 metadata.PLTE_present = true; 363 metadata.PLTE_red = new byte[paletteEntries]; 364 metadata.PLTE_green = new byte[paletteEntries]; 365 metadata.PLTE_blue = new byte[paletteEntries]; 366 367 int index = 0; 368 for (int i = 0; i < numEntries; i++) { 369 metadata.PLTE_red[i] = palette[index++]; 370 metadata.PLTE_green[i] = palette[index++]; 371 metadata.PLTE_blue[i] = palette[index++]; 372 } 373 } 374 375 private void parse_bKGD_chunk() throws IOException { 376 if (metadata.IHDR_colorType == PNG_COLOR_PALETTE) { 377 metadata.bKGD_colorType = PNG_COLOR_PALETTE; 378 metadata.bKGD_index = stream.readUnsignedByte(); 379 } else if (metadata.IHDR_colorType == PNG_COLOR_GRAY || 380 metadata.IHDR_colorType == PNG_COLOR_GRAY_ALPHA) { 381 metadata.bKGD_colorType = PNG_COLOR_GRAY; 382 metadata.bKGD_gray = stream.readUnsignedShort(); 383 } else { // RGB or RGB_ALPHA 384 metadata.bKGD_colorType = PNG_COLOR_RGB; 385 metadata.bKGD_red = stream.readUnsignedShort(); 386 metadata.bKGD_green = stream.readUnsignedShort(); 387 metadata.bKGD_blue = stream.readUnsignedShort(); 388 } 389 390 metadata.bKGD_present = true; 391 } 392 393 private void parse_cHRM_chunk() throws IOException { 394 metadata.cHRM_whitePointX = stream.readInt(); 395 metadata.cHRM_whitePointY = stream.readInt(); 396 metadata.cHRM_redX = stream.readInt(); 397 metadata.cHRM_redY = stream.readInt(); 398 metadata.cHRM_greenX = stream.readInt(); 399 metadata.cHRM_greenY = stream.readInt(); 400 metadata.cHRM_blueX = stream.readInt(); 401 metadata.cHRM_blueY = stream.readInt(); 402 403 metadata.cHRM_present = true; 404 } 405 406 private void parse_gAMA_chunk() throws IOException { 407 int gamma = stream.readInt(); 408 metadata.gAMA_gamma = gamma; 409 410 metadata.gAMA_present = true; 411 } 412 413 private void parse_hIST_chunk(int chunkLength) throws IOException, 414 IIOException 415 { 416 if (!metadata.PLTE_present) { 417 throw new IIOException("hIST chunk without prior PLTE chunk!"); 418 } 419 420 /* According to PNG specification length of 421 * hIST chunk is specified in bytes and 422 * hIST chunk consists of 2 byte elements 423 * (so we expect length is even). 424 */ 425 metadata.hIST_histogram = new char[chunkLength/2]; 426 stream.readFully(metadata.hIST_histogram, 427 0, metadata.hIST_histogram.length); 428 429 metadata.hIST_present = true; 430 } 431 432 private void parse_iCCP_chunk(int chunkLength) throws IOException { 433 String keyword = readNullTerminatedString("ISO-8859-1", 80); 434 int compressedProfileLength = chunkLength - keyword.length() - 2; 435 if (compressedProfileLength <= 0) { 436 throw new IIOException("iCCP chunk length is not proper"); 437 } 438 metadata.iCCP_profileName = keyword; 439 440 metadata.iCCP_compressionMethod = stream.readUnsignedByte(); 441 442 byte[] compressedProfile = 443 new byte[compressedProfileLength]; 444 stream.readFully(compressedProfile); 445 metadata.iCCP_compressedProfile = compressedProfile; 446 447 metadata.iCCP_present = true; 448 } 449 450 private void parse_iTXt_chunk(int chunkLength) throws IOException { 451 long chunkStart = stream.getStreamPosition(); 452 453 String keyword = readNullTerminatedString("ISO-8859-1", 80); 454 metadata.iTXt_keyword.add(keyword); 455 456 int compressionFlag = stream.readUnsignedByte(); 457 metadata.iTXt_compressionFlag.add(Boolean.valueOf(compressionFlag == 1)); 458 459 int compressionMethod = stream.readUnsignedByte(); 460 metadata.iTXt_compressionMethod.add(Integer.valueOf(compressionMethod)); 461 462 long pos = stream.getStreamPosition(); 463 int remainingLen = (int)(chunkStart + chunkLength - pos); 464 String languageTag = readNullTerminatedString("UTF8", remainingLen); 465 metadata.iTXt_languageTag.add(languageTag); 466 467 pos = stream.getStreamPosition(); 468 remainingLen = (int)(chunkStart + chunkLength - pos); 469 if (remainingLen < 0) { 470 throw new IIOException("iTXt chunk length is not proper"); 471 } 472 String translatedKeyword = 473 readNullTerminatedString("UTF8", remainingLen); 474 metadata.iTXt_translatedKeyword.add(translatedKeyword); 475 476 String text; 477 pos = stream.getStreamPosition(); 478 int textLength = (int)(chunkStart + chunkLength - pos); 479 if (textLength < 0) { 480 throw new IIOException("iTXt chunk length is not proper"); 481 } 482 byte[] b = new byte[textLength]; 483 stream.readFully(b); 484 485 if (compressionFlag == 1) { // Decompress the text 486 text = new String(inflate(b), "UTF8"); 487 } else { 488 text = new String(b, "UTF8"); 489 } 490 metadata.iTXt_text.add(text); 491 492 // Check if the text chunk contains image creation time 493 if (keyword.equals(PNGMetadata.tEXt_creationTimeKey)) { 494 // Update Standard/Document/ImageCreationTime from text chunk 495 int index = metadata.iTXt_text.size() - 1; 496 metadata.decodeImageCreationTimeFromTextChunk( 497 metadata.iTXt_text.listIterator(index)); 498 } 499 } 500 501 private void parse_pHYs_chunk() throws IOException { 502 metadata.pHYs_pixelsPerUnitXAxis = stream.readInt(); 503 metadata.pHYs_pixelsPerUnitYAxis = stream.readInt(); 504 metadata.pHYs_unitSpecifier = stream.readUnsignedByte(); 505 506 metadata.pHYs_present = true; 507 } 508 509 private void parse_sBIT_chunk() throws IOException { 510 int colorType = metadata.IHDR_colorType; 511 if (colorType == PNG_COLOR_GRAY || 512 colorType == PNG_COLOR_GRAY_ALPHA) { 513 metadata.sBIT_grayBits = stream.readUnsignedByte(); 514 } else if (colorType == PNG_COLOR_RGB || 515 colorType == PNG_COLOR_PALETTE || 516 colorType == PNG_COLOR_RGB_ALPHA) { 517 metadata.sBIT_redBits = stream.readUnsignedByte(); 518 metadata.sBIT_greenBits = stream.readUnsignedByte(); 519 metadata.sBIT_blueBits = stream.readUnsignedByte(); 520 } 521 522 if (colorType == PNG_COLOR_GRAY_ALPHA || 523 colorType == PNG_COLOR_RGB_ALPHA) { 524 metadata.sBIT_alphaBits = stream.readUnsignedByte(); 525 } 526 527 metadata.sBIT_colorType = colorType; 528 metadata.sBIT_present = true; 529 } 530 531 private void parse_sPLT_chunk(int chunkLength) 532 throws IOException, IIOException { 533 metadata.sPLT_paletteName = readNullTerminatedString("ISO-8859-1", 80); 534 int remainingChunkLength = chunkLength - 535 (metadata.sPLT_paletteName.length() + 1); 536 if (remainingChunkLength <= 0) { 537 throw new IIOException("sPLT chunk length is not proper"); 538 } 539 540 int sampleDepth = stream.readUnsignedByte(); 541 metadata.sPLT_sampleDepth = sampleDepth; 542 543 int numEntries = remainingChunkLength/(4*(sampleDepth/8) + 2); 544 metadata.sPLT_red = new int[numEntries]; 545 metadata.sPLT_green = new int[numEntries]; 546 metadata.sPLT_blue = new int[numEntries]; 547 metadata.sPLT_alpha = new int[numEntries]; 548 metadata.sPLT_frequency = new int[numEntries]; 549 550 if (sampleDepth == 8) { 551 for (int i = 0; i < numEntries; i++) { 552 metadata.sPLT_red[i] = stream.readUnsignedByte(); 553 metadata.sPLT_green[i] = stream.readUnsignedByte(); 554 metadata.sPLT_blue[i] = stream.readUnsignedByte(); 555 metadata.sPLT_alpha[i] = stream.readUnsignedByte(); 556 metadata.sPLT_frequency[i] = stream.readUnsignedShort(); 557 } 558 } else if (sampleDepth == 16) { 559 for (int i = 0; i < numEntries; i++) { 560 metadata.sPLT_red[i] = stream.readUnsignedShort(); 561 metadata.sPLT_green[i] = stream.readUnsignedShort(); 562 metadata.sPLT_blue[i] = stream.readUnsignedShort(); 563 metadata.sPLT_alpha[i] = stream.readUnsignedShort(); 564 metadata.sPLT_frequency[i] = stream.readUnsignedShort(); 565 } 566 } else { 567 throw new IIOException("sPLT sample depth not 8 or 16!"); 568 } 569 570 metadata.sPLT_present = true; 571 } 572 573 private void parse_sRGB_chunk() throws IOException { 574 metadata.sRGB_renderingIntent = stream.readUnsignedByte(); 575 576 metadata.sRGB_present = true; 577 } 578 579 private void parse_tEXt_chunk(int chunkLength) throws IOException { 580 String keyword = readNullTerminatedString("ISO-8859-1", 80); 581 int textLength = chunkLength - keyword.length() - 1; 582 if (textLength < 0) { 583 throw new IIOException("tEXt chunk length is not proper"); 584 } 585 metadata.tEXt_keyword.add(keyword); 586 587 byte[] b = new byte[textLength]; 588 stream.readFully(b); 589 metadata.tEXt_text.add(new String(b, "ISO-8859-1")); 590 591 // Check if the text chunk contains image creation time 592 if (keyword.equals(PNGMetadata.tEXt_creationTimeKey)) { 593 // Update Standard/Document/ImageCreationTime from text chunk 594 int index = metadata.tEXt_text.size() - 1; 595 metadata.decodeImageCreationTimeFromTextChunk( 596 metadata.tEXt_text.listIterator(index)); 597 } 598 } 599 600 private void parse_tIME_chunk() throws IOException { 601 metadata.tIME_year = stream.readUnsignedShort(); 602 metadata.tIME_month = stream.readUnsignedByte(); 603 metadata.tIME_day = stream.readUnsignedByte(); 604 metadata.tIME_hour = stream.readUnsignedByte(); 605 metadata.tIME_minute = stream.readUnsignedByte(); 606 metadata.tIME_second = stream.readUnsignedByte(); 607 608 metadata.tIME_present = true; 609 } 610 611 private void parse_tRNS_chunk(int chunkLength) throws IOException { 612 int colorType = metadata.IHDR_colorType; 613 if (colorType == PNG_COLOR_PALETTE) { 614 if (!metadata.PLTE_present) { 615 processWarningOccurred( 616 "tRNS chunk without prior PLTE chunk, ignoring it."); 617 return; 618 } 619 620 // Alpha table may have fewer entries than RGB palette 621 int maxEntries = metadata.PLTE_red.length; 622 int numEntries = chunkLength; 623 if (numEntries > maxEntries && maxEntries > 0) { 624 processWarningOccurred( 625 "tRNS chunk has more entries than prior PLTE chunk, ignoring extras."); 626 numEntries = maxEntries; 627 } 628 metadata.tRNS_alpha = new byte[numEntries]; 629 metadata.tRNS_colorType = PNG_COLOR_PALETTE; 630 stream.read(metadata.tRNS_alpha, 0, numEntries); 631 stream.skipBytes(chunkLength - numEntries); 632 } else if (colorType == PNG_COLOR_GRAY) { 633 if (chunkLength != 2) { 634 processWarningOccurred( 635 "tRNS chunk for gray image must have length 2, ignoring chunk."); 636 stream.skipBytes(chunkLength); 637 return; 638 } 639 metadata.tRNS_gray = stream.readUnsignedShort(); 640 metadata.tRNS_colorType = PNG_COLOR_GRAY; 641 } else if (colorType == PNG_COLOR_RGB) { 642 if (chunkLength != 6) { 643 processWarningOccurred( 644 "tRNS chunk for RGB image must have length 6, ignoring chunk."); 645 stream.skipBytes(chunkLength); 646 return; 647 } 648 metadata.tRNS_red = stream.readUnsignedShort(); 649 metadata.tRNS_green = stream.readUnsignedShort(); 650 metadata.tRNS_blue = stream.readUnsignedShort(); 651 metadata.tRNS_colorType = PNG_COLOR_RGB; 652 } else { 653 processWarningOccurred( 654 "Gray+Alpha and RGBS images may not have a tRNS chunk, ignoring it."); 655 return; 656 } 657 658 metadata.tRNS_present = true; 659 } 660 661 private static byte[] inflate(byte[] b) throws IOException { 662 InputStream bais = new ByteArrayInputStream(b); 663 InputStream iis = new InflaterInputStream(bais); 664 ByteArrayOutputStream baos = new ByteArrayOutputStream(); 665 666 int c; 667 try { 668 while ((c = iis.read()) != -1) { 669 baos.write(c); 670 } 671 } finally { 672 iis.close(); 673 } 674 return baos.toByteArray(); 675 } 676 677 private void parse_zTXt_chunk(int chunkLength) throws IOException { 678 String keyword = readNullTerminatedString("ISO-8859-1", 80); 679 int textLength = chunkLength - keyword.length() - 2; 680 if (textLength < 0) { 681 throw new IIOException("zTXt chunk length is not proper"); 682 } 683 metadata.zTXt_keyword.add(keyword); 684 685 int method = stream.readUnsignedByte(); 686 metadata.zTXt_compressionMethod.add(method); 687 688 byte[] b = new byte[textLength]; 689 stream.readFully(b); 690 metadata.zTXt_text.add(new String(inflate(b), "ISO-8859-1")); 691 692 // Check if the text chunk contains image creation time 693 if (keyword.equals(PNGMetadata.tEXt_creationTimeKey)) { 694 // Update Standard/Document/ImageCreationTime from text chunk 695 int index = metadata.zTXt_text.size() - 1; 696 metadata.decodeImageCreationTimeFromTextChunk( 697 metadata.zTXt_text.listIterator(index)); 698 } 699 } 700 701 private void readMetadata() throws IIOException { 702 if (gotMetadata) { 703 return; 704 } 705 706 readHeader(); 707 708 /* 709 * Optimization: We can skip reading metadata if ignoreMetadata 710 * flag is set and colorType is not PNG_COLOR_PALETTE. However, 711 * we parse tRNS chunk to retrieve the transparent color from the 712 * metadata. Doing so, helps PNGImageReader to appropriately 713 * identify and set transparent pixels in the decoded image for 714 * colorType PNG_COLOR_RGB and PNG_COLOR_GRAY. 715 */ 716 int colorType = metadata.IHDR_colorType; 717 if (ignoreMetadata && colorType != PNG_COLOR_PALETTE) { 718 try { 719 while (true) { 720 int chunkLength = stream.readInt(); 721 722 // verify the chunk length first 723 if (chunkLength < 0 || chunkLength + 4 < 0) { 724 throw new IIOException("Invalid chunk length " + chunkLength); 725 } 726 727 int chunkType = stream.readInt(); 728 729 if (chunkType == IDAT_TYPE) { 730 // We've reached the first IDAT chunk position 731 stream.skipBytes(-8); 732 imageStartPosition = stream.getStreamPosition(); 733 /* 734 * According to PNG specification tRNS chunk must 735 * precede the first IDAT chunk. So we can stop 736 * reading metadata. 737 */ 738 break; 739 } else if (chunkType == tRNS_TYPE) { 740 parse_tRNS_chunk(chunkLength); 741 // After parsing tRNS chunk we will skip 4 CRC bytes 742 stream.skipBytes(4); 743 } else { 744 // Skip the chunk plus the 4 CRC bytes that follow 745 stream.skipBytes(chunkLength + 4); 746 } 747 } 748 } catch (IOException e) { 749 throw new IIOException("Error skipping PNG metadata", e); 750 } 751 752 gotMetadata = true; 753 return; 754 } 755 756 try { 757 loop: while (true) { 758 int chunkLength = stream.readInt(); 759 int chunkType = stream.readInt(); 760 // Initialize chunkCRC, value assigned has no significance 761 int chunkCRC = -1; 762 763 // verify the chunk length 764 if (chunkLength < 0) { 765 throw new IIOException("Invalid chunk length " + chunkLength); 766 }; 767 768 try { 769 /* 770 * As per PNG specification all chunks should have 771 * 4 byte CRC. But there are some images where 772 * CRC is not present/corrupt for IEND chunk. 773 * And these type of images are supported by other 774 * decoders. So as soon as we hit chunk type 775 * for IEND chunk stop reading metadata. 776 */ 777 if (chunkType != IEND_TYPE) { 778 stream.mark(); 779 stream.seek(stream.getStreamPosition() + chunkLength); 780 chunkCRC = stream.readInt(); 781 stream.reset(); 782 } 783 } catch (IOException e) { 784 throw new IIOException("Invalid chunk length " + chunkLength); 785 } 786 787 switch (chunkType) { 788 case IDAT_TYPE: 789 // If chunk type is 'IDAT', we've reached the image data. 790 if (imageStartPosition == -1L) { 791 /* 792 * The PNG specification mandates that if colorType is 793 * PNG_COLOR_PALETTE then the PLTE chunk should appear 794 * before the first IDAT chunk. 795 */ 796 if (colorType == PNG_COLOR_PALETTE && 797 !(metadata.PLTE_present)) 798 { 799 throw new IIOException("Required PLTE chunk" 800 + " missing"); 801 } 802 /* 803 * PNGs may contain multiple IDAT chunks containing 804 * a portion of image data. We store the position of 805 * the first IDAT chunk and continue with iteration 806 * of other chunks that follow image data. 807 */ 808 imageStartPosition = stream.getStreamPosition() - 8; 809 } 810 // Move to the CRC byte location. 811 stream.skipBytes(chunkLength); 812 break; 813 case IEND_TYPE: 814 /* 815 * If the chunk type is 'IEND', we've reached end of image. 816 * Seek to the first IDAT chunk for subsequent decoding. 817 */ 818 stream.seek(imageStartPosition); 819 820 /* 821 * flushBefore discards the portion of the stream before 822 * the indicated position. Hence this should be used after 823 * we complete iteration over available chunks including 824 * those that appear after the IDAT. 825 */ 826 stream.flushBefore(stream.getStreamPosition()); 827 break loop; 828 case PLTE_TYPE: 829 parse_PLTE_chunk(chunkLength); 830 break; 831 case bKGD_TYPE: 832 parse_bKGD_chunk(); 833 break; 834 case cHRM_TYPE: 835 parse_cHRM_chunk(); 836 break; 837 case gAMA_TYPE: 838 parse_gAMA_chunk(); 839 break; 840 case hIST_TYPE: 841 parse_hIST_chunk(chunkLength); 842 break; 843 case iCCP_TYPE: 844 parse_iCCP_chunk(chunkLength); 845 break; 846 case iTXt_TYPE: 847 if (ignoreMetadata) { 848 stream.skipBytes(chunkLength); 849 } else { 850 parse_iTXt_chunk(chunkLength); 851 } 852 break; 853 case pHYs_TYPE: 854 parse_pHYs_chunk(); 855 break; 856 case sBIT_TYPE: 857 parse_sBIT_chunk(); 858 break; 859 case sPLT_TYPE: 860 parse_sPLT_chunk(chunkLength); 861 break; 862 case sRGB_TYPE: 863 parse_sRGB_chunk(); 864 break; 865 case tEXt_TYPE: 866 parse_tEXt_chunk(chunkLength); 867 break; 868 case tIME_TYPE: 869 parse_tIME_chunk(); 870 break; 871 case tRNS_TYPE: 872 parse_tRNS_chunk(chunkLength); 873 break; 874 case zTXt_TYPE: 875 if (ignoreMetadata) { 876 stream.skipBytes(chunkLength); 877 } else { 878 parse_zTXt_chunk(chunkLength); 879 } 880 break; 881 default: 882 // Read an unknown chunk 883 byte[] b = new byte[chunkLength]; 884 stream.readFully(b); 885 886 StringBuilder chunkName = new StringBuilder(4); 887 chunkName.append((char)(chunkType >>> 24)); 888 chunkName.append((char)((chunkType >> 16) & 0xff)); 889 chunkName.append((char)((chunkType >> 8) & 0xff)); 890 chunkName.append((char)(chunkType & 0xff)); 891 892 int ancillaryBit = chunkType >>> 28; 893 if (ancillaryBit == 0) { 894 processWarningOccurred( 895 "Encountered unknown chunk with critical bit set!"); 896 } 897 898 metadata.unknownChunkType.add(chunkName.toString()); 899 metadata.unknownChunkData.add(b); 900 break; 901 } 902 903 // double check whether all chunk data were consumed 904 if (chunkCRC != stream.readInt()) { 905 throw new IIOException("Failed to read a chunk of type " + 906 chunkType); 907 } 908 } 909 } catch (IOException e) { 910 throw new IIOException("Error reading PNG metadata", e); 911 } 912 913 gotMetadata = true; 914 } 915 916 // Data filtering methods 917 918 private static void decodeSubFilter(byte[] curr, int coff, int count, 919 int bpp) { 920 for (int i = bpp; i < count; i++) { 921 int val; 922 923 val = curr[i + coff] & 0xff; 924 val += curr[i + coff - bpp] & 0xff; 925 926 curr[i + coff] = (byte)val; 927 } 928 } 929 930 private static void decodeUpFilter(byte[] curr, int coff, 931 byte[] prev, int poff, 932 int count) { 933 for (int i = 0; i < count; i++) { 934 int raw = curr[i + coff] & 0xff; 935 int prior = prev[i + poff] & 0xff; 936 937 curr[i + coff] = (byte)(raw + prior); 938 } 939 } 940 941 private static void decodeAverageFilter(byte[] curr, int coff, 942 byte[] prev, int poff, 943 int count, int bpp) { 944 int raw, priorPixel, priorRow; 945 946 for (int i = 0; i < bpp; i++) { 947 raw = curr[i + coff] & 0xff; 948 priorRow = prev[i + poff] & 0xff; 949 950 curr[i + coff] = (byte)(raw + priorRow/2); 951 } 952 953 for (int i = bpp; i < count; i++) { 954 raw = curr[i + coff] & 0xff; 955 priorPixel = curr[i + coff - bpp] & 0xff; 956 priorRow = prev[i + poff] & 0xff; 957 958 curr[i + coff] = (byte)(raw + (priorPixel + priorRow)/2); 959 } 960 } 961 962 private static int paethPredictor(int a, int b, int c) { 963 int p = a + b - c; 964 int pa = Math.abs(p - a); 965 int pb = Math.abs(p - b); 966 int pc = Math.abs(p - c); 967 968 if ((pa <= pb) && (pa <= pc)) { 969 return a; 970 } else if (pb <= pc) { 971 return b; 972 } else { 973 return c; 974 } 975 } 976 977 private static void decodePaethFilter(byte[] curr, int coff, 978 byte[] prev, int poff, 979 int count, int bpp) { 980 int raw, priorPixel, priorRow, priorRowPixel; 981 982 for (int i = 0; i < bpp; i++) { 983 raw = curr[i + coff] & 0xff; 984 priorRow = prev[i + poff] & 0xff; 985 986 curr[i + coff] = (byte)(raw + priorRow); 987 } 988 989 for (int i = bpp; i < count; i++) { 990 raw = curr[i + coff] & 0xff; 991 priorPixel = curr[i + coff - bpp] & 0xff; 992 priorRow = prev[i + poff] & 0xff; 993 priorRowPixel = prev[i + poff - bpp] & 0xff; 994 995 curr[i + coff] = (byte)(raw + paethPredictor(priorPixel, 996 priorRow, 997 priorRowPixel)); 998 } 999 } 1000 1001 private static final int[][] bandOffsets = { 1002 null, 1003 { 0 }, // G 1004 { 0, 1 }, // GA in GA order 1005 { 0, 1, 2 }, // RGB in RGB order 1006 { 0, 1, 2, 3 } // RGBA in RGBA order 1007 }; 1008 1009 private WritableRaster createRaster(int width, int height, int bands, 1010 int scanlineStride, 1011 int bitDepth) { 1012 1013 DataBuffer dataBuffer; 1014 WritableRaster ras = null; 1015 Point origin = new Point(0, 0); 1016 if ((bitDepth < 8) && (bands == 1)) { 1017 dataBuffer = new DataBufferByte(height*scanlineStride); 1018 ras = Raster.createPackedRaster(dataBuffer, 1019 width, height, 1020 bitDepth, 1021 origin); 1022 } else if (bitDepth <= 8) { 1023 dataBuffer = new DataBufferByte(height*scanlineStride); 1024 ras = Raster.createInterleavedRaster(dataBuffer, 1025 width, height, 1026 scanlineStride, 1027 bands, 1028 bandOffsets[bands], 1029 origin); 1030 } else { 1031 dataBuffer = new DataBufferUShort(height*scanlineStride); 1032 ras = Raster.createInterleavedRaster(dataBuffer, 1033 width, height, 1034 scanlineStride, 1035 bands, 1036 bandOffsets[bands], 1037 origin); 1038 } 1039 1040 return ras; 1041 } 1042 1043 private void skipPass(int passWidth, int passHeight) 1044 throws IOException, IIOException { 1045 if ((passWidth == 0) || (passHeight == 0)) { 1046 return; 1047 } 1048 1049 int inputBands = inputBandsForColorType[metadata.IHDR_colorType]; 1050 int bitsPerRow = Math. 1051 multiplyExact((inputBands * metadata.IHDR_bitDepth), passWidth); 1052 int bytesPerRow = (bitsPerRow + 7) / 8; 1053 1054 // Read the image row-by-row 1055 for (int srcY = 0; srcY < passHeight; srcY++) { 1056 // Skip filter byte and the remaining row bytes 1057 pixelStream.skipBytes(1 + bytesPerRow); 1058 } 1059 } 1060 1061 private void updateImageProgress(int newPixels) { 1062 pixelsDone += newPixels; 1063 processImageProgress(100.0F*pixelsDone/totalPixels); 1064 } 1065 1066 private void decodePass(int passNum, 1067 int xStart, int yStart, 1068 int xStep, int yStep, 1069 int passWidth, int passHeight) throws IOException { 1070 1071 if ((passWidth == 0) || (passHeight == 0)) { 1072 return; 1073 } 1074 1075 WritableRaster imRas = theImage.getWritableTile(0, 0); 1076 int dstMinX = imRas.getMinX(); 1077 int dstMaxX = dstMinX + imRas.getWidth() - 1; 1078 int dstMinY = imRas.getMinY(); 1079 int dstMaxY = dstMinY + imRas.getHeight() - 1; 1080 1081 // Determine which pixels will be updated in this pass 1082 int[] vals = 1083 ReaderUtil.computeUpdatedPixels(sourceRegion, 1084 destinationOffset, 1085 dstMinX, dstMinY, 1086 dstMaxX, dstMaxY, 1087 sourceXSubsampling, 1088 sourceYSubsampling, 1089 xStart, yStart, 1090 passWidth, passHeight, 1091 xStep, yStep); 1092 int updateMinX = vals[0]; 1093 int updateMinY = vals[1]; 1094 int updateWidth = vals[2]; 1095 int updateXStep = vals[4]; 1096 int updateYStep = vals[5]; 1097 1098 int bitDepth = metadata.IHDR_bitDepth; 1099 int inputBands = inputBandsForColorType[metadata.IHDR_colorType]; 1100 int bytesPerPixel = (bitDepth == 16) ? 2 : 1; 1101 bytesPerPixel *= inputBands; 1102 1103 int bitsPerRow = Math.multiplyExact((inputBands * bitDepth), passWidth); 1104 int bytesPerRow = (bitsPerRow + 7) / 8; 1105 int eltsPerRow = (bitDepth == 16) ? bytesPerRow/2 : bytesPerRow; 1106 1107 // If no pixels need updating, just skip the input data 1108 if (updateWidth == 0) { 1109 for (int srcY = 0; srcY < passHeight; srcY++) { 1110 // Update count of pixels read 1111 updateImageProgress(passWidth); 1112 /* 1113 * If read has been aborted, just return 1114 * processReadAborted will be called later 1115 */ 1116 if (abortRequested()) { 1117 return; 1118 } 1119 // Skip filter byte and the remaining row bytes 1120 pixelStream.skipBytes(1 + bytesPerRow); 1121 } 1122 return; 1123 } 1124 1125 // Backwards map from destination pixels 1126 // (dstX = updateMinX + k*updateXStep) 1127 // to source pixels (sourceX), and then 1128 // to offset and skip in passRow (srcX and srcXStep) 1129 int sourceX = 1130 (updateMinX - destinationOffset.x)*sourceXSubsampling + 1131 sourceRegion.x; 1132 int srcX = (sourceX - xStart)/xStep; 1133 1134 // Compute the step factor in the source 1135 int srcXStep = updateXStep*sourceXSubsampling/xStep; 1136 1137 byte[] byteData = null; 1138 short[] shortData = null; 1139 byte[] curr = new byte[bytesPerRow]; 1140 byte[] prior = new byte[bytesPerRow]; 1141 1142 // Create a 1-row tall Raster to hold the data 1143 WritableRaster passRow = createRaster(passWidth, 1, inputBands, 1144 eltsPerRow, 1145 bitDepth); 1146 1147 // Create an array suitable for holding one pixel 1148 int[] ps = passRow.getPixel(0, 0, (int[])null); 1149 1150 DataBuffer dataBuffer = passRow.getDataBuffer(); 1151 int type = dataBuffer.getDataType(); 1152 if (type == DataBuffer.TYPE_BYTE) { 1153 byteData = ((DataBufferByte)dataBuffer).getData(); 1154 } else { 1155 shortData = ((DataBufferUShort)dataBuffer).getData(); 1156 } 1157 1158 processPassStarted(theImage, 1159 passNum, 1160 sourceMinProgressivePass, 1161 sourceMaxProgressivePass, 1162 updateMinX, updateMinY, 1163 updateXStep, updateYStep, 1164 destinationBands); 1165 1166 // Handle source and destination bands 1167 if (sourceBands != null) { 1168 passRow = passRow.createWritableChild(0, 0, 1169 passRow.getWidth(), 1, 1170 0, 0, 1171 sourceBands); 1172 } 1173 if (destinationBands != null) { 1174 imRas = imRas.createWritableChild(0, 0, 1175 imRas.getWidth(), 1176 imRas.getHeight(), 1177 0, 0, 1178 destinationBands); 1179 } 1180 1181 // Determine if all of the relevant output bands have the 1182 // same bit depth as the source data 1183 boolean adjustBitDepths = false; 1184 int[] outputSampleSize = imRas.getSampleModel().getSampleSize(); 1185 for (int b = 0; b < inputBands; b++) { 1186 if (outputSampleSize[b] != bitDepth) { 1187 adjustBitDepths = true; 1188 break; 1189 } 1190 } 1191 1192 // If the bit depths differ, create a lookup table per band to perform 1193 // the conversion 1194 int[][] scale = null; 1195 if (adjustBitDepths) { 1196 int maxInSample = (1 << bitDepth) - 1; 1197 int halfMaxInSample = maxInSample/2; 1198 scale = new int[inputBands][]; 1199 for (int b = 0; b < inputBands; b++) { 1200 int maxOutSample = (1 << outputSampleSize[b]) - 1; 1201 scale[b] = new int[maxInSample + 1]; 1202 for (int s = 0; s <= maxInSample; s++) { 1203 scale[b][s] = 1204 (s*maxOutSample + halfMaxInSample)/maxInSample; 1205 } 1206 } 1207 } 1208 1209 // Limit passRow to relevant area for the case where we 1210 // will can setRect to copy a contiguous span 1211 boolean useSetRect = srcXStep == 1 && 1212 updateXStep == 1 && 1213 !adjustBitDepths && 1214 (imRas instanceof ByteInterleavedRaster); 1215 1216 if (useSetRect) { 1217 passRow = passRow.createWritableChild(srcX, 0, 1218 updateWidth, 1, 1219 0, 0, 1220 null); 1221 } 1222 1223 // Decode the (sub)image row-by-row 1224 for (int srcY = 0; srcY < passHeight; srcY++) { 1225 // Update count of pixels read 1226 updateImageProgress(passWidth); 1227 /* 1228 * If read has been aborted, just return 1229 * processReadAborted will be called later 1230 */ 1231 if (abortRequested()) { 1232 return; 1233 } 1234 // Read the filter type byte and a row of data 1235 int filter = pixelStream.read(); 1236 try { 1237 // Swap curr and prior 1238 byte[] tmp = prior; 1239 prior = curr; 1240 curr = tmp; 1241 1242 pixelStream.readFully(curr, 0, bytesPerRow); 1243 } catch (java.util.zip.ZipException ze) { 1244 // TODO - throw a more meaningful exception 1245 throw ze; 1246 } 1247 1248 switch (filter) { 1249 case PNG_FILTER_NONE: 1250 break; 1251 case PNG_FILTER_SUB: 1252 decodeSubFilter(curr, 0, bytesPerRow, bytesPerPixel); 1253 break; 1254 case PNG_FILTER_UP: 1255 decodeUpFilter(curr, 0, prior, 0, bytesPerRow); 1256 break; 1257 case PNG_FILTER_AVERAGE: 1258 decodeAverageFilter(curr, 0, prior, 0, bytesPerRow, 1259 bytesPerPixel); 1260 break; 1261 case PNG_FILTER_PAETH: 1262 decodePaethFilter(curr, 0, prior, 0, bytesPerRow, 1263 bytesPerPixel); 1264 break; 1265 default: 1266 throw new IIOException("Unknown row filter type (= " + 1267 filter + ")!"); 1268 } 1269 1270 // Copy data into passRow byte by byte 1271 if (bitDepth < 16) { 1272 System.arraycopy(curr, 0, byteData, 0, bytesPerRow); 1273 } else { 1274 int idx = 0; 1275 for (int j = 0; j < eltsPerRow; j++) { 1276 shortData[j] = 1277 (short)((curr[idx] << 8) | (curr[idx + 1] & 0xff)); 1278 idx += 2; 1279 } 1280 } 1281 1282 // True Y position in source 1283 int sourceY = srcY*yStep + yStart; 1284 if ((sourceY >= sourceRegion.y) && 1285 (sourceY < sourceRegion.y + sourceRegion.height) && 1286 (((sourceY - sourceRegion.y) % 1287 sourceYSubsampling) == 0)) { 1288 1289 int dstY = destinationOffset.y + 1290 (sourceY - sourceRegion.y)/sourceYSubsampling; 1291 if (dstY < dstMinY) { 1292 continue; 1293 } 1294 if (dstY > dstMaxY) { 1295 break; 1296 } 1297 1298 /* 1299 * For PNG images of color type PNG_COLOR_RGB or PNG_COLOR_GRAY 1300 * that contain a specific transparent color (given by tRNS 1301 * chunk), we compare the decoded pixel color with the color 1302 * given by tRNS chunk to set the alpha on the destination. 1303 */ 1304 boolean tRNSTransparentPixelPresent = 1305 theImage.getSampleModel().getNumBands() == inputBands + 1 && 1306 metadata.hasTransparentColor(); 1307 if (useSetRect && 1308 !tRNSTransparentPixelPresent) { 1309 imRas.setRect(updateMinX, dstY, passRow); 1310 } else { 1311 int newSrcX = srcX; 1312 1313 /* 1314 * Create intermediate array to fill the extra alpha 1315 * channel when tRNSTransparentPixelPresent is true. 1316 */ 1317 final int[] temp = new int[inputBands + 1]; 1318 final int opaque = (bitDepth < 16) ? 255 : 65535; 1319 for (int dstX = updateMinX; 1320 dstX < updateMinX + updateWidth; 1321 dstX += updateXStep) { 1322 1323 passRow.getPixel(newSrcX, 0, ps); 1324 if (adjustBitDepths) { 1325 for (int b = 0; b < inputBands; b++) { 1326 ps[b] = scale[b][ps[b]]; 1327 } 1328 } 1329 if (tRNSTransparentPixelPresent) { 1330 if (metadata.tRNS_colorType == PNG_COLOR_RGB) { 1331 temp[0] = ps[0]; 1332 temp[1] = ps[1]; 1333 temp[2] = ps[2]; 1334 if (ps[0] == metadata.tRNS_red && 1335 ps[1] == metadata.tRNS_green && 1336 ps[2] == metadata.tRNS_blue) { 1337 temp[3] = 0; 1338 } else { 1339 temp[3] = opaque; 1340 } 1341 } else { 1342 // when tRNS_colorType is PNG_COLOR_GRAY 1343 temp[0] = ps[0]; 1344 if (ps[0] == metadata.tRNS_gray) { 1345 temp[1] = 0; 1346 } else { 1347 temp[1] = opaque; 1348 } 1349 } 1350 imRas.setPixel(dstX, dstY, temp); 1351 } else { 1352 imRas.setPixel(dstX, dstY, ps); 1353 } 1354 newSrcX += srcXStep; 1355 } 1356 } 1357 1358 processImageUpdate(theImage, 1359 updateMinX, dstY, 1360 updateWidth, 1, 1361 updateXStep, updateYStep, 1362 destinationBands); 1363 } 1364 } 1365 1366 processPassComplete(theImage); 1367 } 1368 1369 private void decodeImage() 1370 throws IOException, IIOException { 1371 int width = metadata.IHDR_width; 1372 int height = metadata.IHDR_height; 1373 1374 this.pixelsDone = 0; 1375 this.totalPixels = width*height; 1376 1377 if (metadata.IHDR_interlaceMethod == 0) { 1378 decodePass(0, 0, 0, 1, 1, width, height); 1379 } else { 1380 for (int i = 0; i <= sourceMaxProgressivePass; i++) { 1381 int XOffset = adam7XOffset[i]; 1382 int YOffset = adam7YOffset[i]; 1383 int XSubsampling = adam7XSubsampling[i]; 1384 int YSubsampling = adam7YSubsampling[i]; 1385 int xbump = adam7XSubsampling[i + 1] - 1; 1386 int ybump = adam7YSubsampling[i + 1] - 1; 1387 1388 if (i >= sourceMinProgressivePass) { 1389 decodePass(i, 1390 XOffset, 1391 YOffset, 1392 XSubsampling, 1393 YSubsampling, 1394 (width + xbump)/XSubsampling, 1395 (height + ybump)/YSubsampling); 1396 } else { 1397 skipPass((width + xbump)/XSubsampling, 1398 (height + ybump)/YSubsampling); 1399 } 1400 1401 /* 1402 * If read has been aborted, just return 1403 * processReadAborted will be called later 1404 */ 1405 if (abortRequested()) { 1406 return; 1407 } 1408 } 1409 } 1410 } 1411 1412 private void readImage(ImageReadParam param) throws IIOException { 1413 readMetadata(); 1414 1415 int width = metadata.IHDR_width; 1416 int height = metadata.IHDR_height; 1417 1418 // Init default values 1419 sourceXSubsampling = 1; 1420 sourceYSubsampling = 1; 1421 sourceMinProgressivePass = 0; 1422 sourceMaxProgressivePass = 6; 1423 sourceBands = null; 1424 destinationBands = null; 1425 destinationOffset = new Point(0, 0); 1426 1427 // If an ImageReadParam is available, get values from it 1428 if (param != null) { 1429 sourceXSubsampling = param.getSourceXSubsampling(); 1430 sourceYSubsampling = param.getSourceYSubsampling(); 1431 1432 sourceMinProgressivePass = 1433 Math.max(param.getSourceMinProgressivePass(), 0); 1434 sourceMaxProgressivePass = 1435 Math.min(param.getSourceMaxProgressivePass(), 6); 1436 1437 sourceBands = param.getSourceBands(); 1438 destinationBands = param.getDestinationBands(); 1439 destinationOffset = param.getDestinationOffset(); 1440 } 1441 Inflater inf = null; 1442 try { 1443 stream.seek(imageStartPosition); 1444 1445 Enumeration<InputStream> e = new PNGImageDataEnumeration(stream); 1446 InputStream is = new SequenceInputStream(e); 1447 1448 /* InflaterInputStream uses an Inflater instance which consumes 1449 * native (non-GC visible) resources. This is normally implicitly 1450 * freed when the stream is closed. However since the 1451 * InflaterInputStream wraps a client-supplied input stream, 1452 * we cannot close it. 1453 * But the app may depend on GC finalization to close the stream. 1454 * Therefore to ensure timely freeing of native resources we 1455 * explicitly create the Inflater instance and free its resources 1456 * when we are done with the InflaterInputStream by calling 1457 * inf.end(); 1458 */ 1459 inf = new Inflater(); 1460 is = new InflaterInputStream(is, inf); 1461 is = new BufferedInputStream(is); 1462 this.pixelStream = new DataInputStream(is); 1463 1464 /* 1465 * PNG spec declares that valid range for width 1466 * and height is [1, 2^31-1], so here we may fail to allocate 1467 * a buffer for destination image due to memory limitation. 1468 * 1469 * If the read operation triggers OutOfMemoryError, the same 1470 * will be wrapped in an IIOException at PNGImageReader.read 1471 * method. 1472 * 1473 * The recovery strategy for this case should be defined at 1474 * the level of application, so we will not try to estimate 1475 * the required amount of the memory and/or handle OOM in 1476 * any way. 1477 */ 1478 theImage = getDestination(param, 1479 getImageTypes(0), 1480 width, 1481 height); 1482 1483 Rectangle destRegion = new Rectangle(0, 0, 0, 0); 1484 sourceRegion = new Rectangle(0, 0, 0, 0); 1485 computeRegions(param, width, height, 1486 theImage, 1487 sourceRegion, destRegion); 1488 destinationOffset.setLocation(destRegion.getLocation()); 1489 1490 // At this point the header has been read and we know 1491 // how many bands are in the image, so perform checking 1492 // of the read param. 1493 int colorType = metadata.IHDR_colorType; 1494 if (theImage.getSampleModel().getNumBands() 1495 == inputBandsForColorType[colorType] + 1 1496 && metadata.hasTransparentColor()) { 1497 checkReadParamBandSettings(param, 1498 inputBandsForColorType[colorType] + 1, 1499 theImage.getSampleModel().getNumBands()); 1500 } else { 1501 checkReadParamBandSettings(param, 1502 inputBandsForColorType[colorType], 1503 theImage.getSampleModel().getNumBands()); 1504 } 1505 1506 clearAbortRequest(); 1507 processImageStarted(0); 1508 if (abortRequested()) { 1509 processReadAborted(); 1510 } else { 1511 decodeImage(); 1512 if (abortRequested()) { 1513 processReadAborted(); 1514 } else { 1515 processImageComplete(); 1516 } 1517 } 1518 1519 } catch (IOException e) { 1520 throw new IIOException("Error reading PNG image data", e); 1521 } finally { 1522 if (inf != null) { 1523 inf.end(); 1524 } 1525 } 1526 } 1527 1528 public int getNumImages(boolean allowSearch) throws IIOException { 1529 if (stream == null) { 1530 throw new IllegalStateException("No input source set!"); 1531 } 1532 if (seekForwardOnly && allowSearch) { 1533 throw new IllegalStateException 1534 ("seekForwardOnly and allowSearch can't both be true!"); 1535 } 1536 return 1; 1537 } 1538 1539 public int getWidth(int imageIndex) throws IIOException { 1540 if (imageIndex != 0) { 1541 throw new IndexOutOfBoundsException("imageIndex != 0!"); 1542 } 1543 1544 readHeader(); 1545 1546 return metadata.IHDR_width; 1547 } 1548 1549 public int getHeight(int imageIndex) throws IIOException { 1550 if (imageIndex != 0) { 1551 throw new IndexOutOfBoundsException("imageIndex != 0!"); 1552 } 1553 1554 readHeader(); 1555 1556 return metadata.IHDR_height; 1557 } 1558 1559 public Iterator<ImageTypeSpecifier> getImageTypes(int imageIndex) 1560 throws IIOException 1561 { 1562 if (imageIndex != 0) { 1563 throw new IndexOutOfBoundsException("imageIndex != 0!"); 1564 } 1565 1566 readHeader(); 1567 1568 ArrayList<ImageTypeSpecifier> l = 1569 new ArrayList<ImageTypeSpecifier>(1); 1570 1571 ColorSpace rgb; 1572 ColorSpace gray; 1573 int[] bandOffsets; 1574 1575 int bitDepth = metadata.IHDR_bitDepth; 1576 int colorType = metadata.IHDR_colorType; 1577 1578 int dataType; 1579 if (bitDepth <= 8) { 1580 dataType = DataBuffer.TYPE_BYTE; 1581 } else { 1582 dataType = DataBuffer.TYPE_USHORT; 1583 } 1584 1585 switch (colorType) { 1586 /* 1587 * For PNG images of color type PNG_COLOR_RGB or PNG_COLOR_GRAY that 1588 * contain a specific transparent color (given by tRNS chunk), we add 1589 * ImageTypeSpecifier(s) that support transparency to the list of 1590 * supported image types. 1591 */ 1592 case PNG_COLOR_GRAY: 1593 readMetadata(); // Need tRNS chunk 1594 1595 if (metadata.hasTransparentColor()) { 1596 gray = ColorSpace.getInstance(ColorSpace.CS_GRAY); 1597 bandOffsets = new int[2]; 1598 bandOffsets[0] = 0; 1599 bandOffsets[1] = 1; 1600 l.add(ImageTypeSpecifier.createInterleaved(gray, 1601 bandOffsets, 1602 dataType, 1603 true, 1604 false)); 1605 } 1606 // Packed grayscale 1607 l.add(ImageTypeSpecifier.createGrayscale(bitDepth, 1608 dataType, 1609 false)); 1610 break; 1611 1612 case PNG_COLOR_RGB: 1613 readMetadata(); // Need tRNS chunk 1614 1615 if (bitDepth == 8) { 1616 if (metadata.hasTransparentColor()) { 1617 l.add(ImageTypeSpecifier.createFromBufferedImageType( 1618 BufferedImage.TYPE_4BYTE_ABGR)); 1619 } 1620 // some standard types of buffered images 1621 // which can be used as destination 1622 l.add(ImageTypeSpecifier.createFromBufferedImageType( 1623 BufferedImage.TYPE_3BYTE_BGR)); 1624 1625 l.add(ImageTypeSpecifier.createFromBufferedImageType( 1626 BufferedImage.TYPE_INT_RGB)); 1627 1628 l.add(ImageTypeSpecifier.createFromBufferedImageType( 1629 BufferedImage.TYPE_INT_BGR)); 1630 1631 } 1632 1633 if (metadata.hasTransparentColor()) { 1634 rgb = ColorSpace.getInstance(ColorSpace.CS_sRGB); 1635 bandOffsets = new int[4]; 1636 bandOffsets[0] = 0; 1637 bandOffsets[1] = 1; 1638 bandOffsets[2] = 2; 1639 bandOffsets[3] = 3; 1640 1641 l.add(ImageTypeSpecifier. 1642 createInterleaved(rgb, bandOffsets, 1643 dataType, true, false)); 1644 } 1645 // Component R, G, B 1646 rgb = ColorSpace.getInstance(ColorSpace.CS_sRGB); 1647 bandOffsets = new int[3]; 1648 bandOffsets[0] = 0; 1649 bandOffsets[1] = 1; 1650 bandOffsets[2] = 2; 1651 l.add(ImageTypeSpecifier.createInterleaved(rgb, 1652 bandOffsets, 1653 dataType, 1654 false, 1655 false)); 1656 break; 1657 1658 case PNG_COLOR_PALETTE: 1659 readMetadata(); // Need tRNS chunk 1660 1661 /* 1662 * The PLTE chunk spec says: 1663 * 1664 * The number of palette entries must not exceed the range that 1665 * can be represented in the image bit depth (for example, 2^4 = 16 1666 * for a bit depth of 4). It is permissible to have fewer entries 1667 * than the bit depth would allow. In that case, any out-of-range 1668 * pixel value found in the image data is an error. 1669 * 1670 * http://www.libpng.org/pub/png/spec/1.2/PNG-Chunks.html#C.PLTE 1671 * 1672 * Consequently, the case when the palette length is smaller than 1673 * 2^bitDepth is legal in the view of PNG spec. 1674 * 1675 * However the spec of createIndexed() method demands the exact 1676 * equality of the palette lengh and number of possible palette 1677 * entries (2^bitDepth). 1678 * 1679 * {@link javax.imageio.ImageTypeSpecifier.html#createIndexed} 1680 * 1681 * In order to avoid this contradiction we need to extend the 1682 * palette arrays to the limit defined by the bitDepth. 1683 */ 1684 1685 int plength = 1 << bitDepth; 1686 1687 byte[] red = metadata.PLTE_red; 1688 byte[] green = metadata.PLTE_green; 1689 byte[] blue = metadata.PLTE_blue; 1690 1691 if (metadata.PLTE_red.length < plength) { 1692 red = Arrays.copyOf(metadata.PLTE_red, plength); 1693 Arrays.fill(red, metadata.PLTE_red.length, plength, 1694 metadata.PLTE_red[metadata.PLTE_red.length - 1]); 1695 1696 green = Arrays.copyOf(metadata.PLTE_green, plength); 1697 Arrays.fill(green, metadata.PLTE_green.length, plength, 1698 metadata.PLTE_green[metadata.PLTE_green.length - 1]); 1699 1700 blue = Arrays.copyOf(metadata.PLTE_blue, plength); 1701 Arrays.fill(blue, metadata.PLTE_blue.length, plength, 1702 metadata.PLTE_blue[metadata.PLTE_blue.length - 1]); 1703 1704 } 1705 1706 // Alpha from tRNS chunk may have fewer entries than 1707 // the RGB LUTs from the PLTE chunk; if so, pad with 1708 // 255. 1709 byte[] alpha = null; 1710 if (metadata.tRNS_present && (metadata.tRNS_alpha != null)) { 1711 if (metadata.tRNS_alpha.length == red.length) { 1712 alpha = metadata.tRNS_alpha; 1713 } else { 1714 alpha = Arrays.copyOf(metadata.tRNS_alpha, red.length); 1715 Arrays.fill(alpha, 1716 metadata.tRNS_alpha.length, 1717 red.length, (byte)255); 1718 } 1719 } 1720 1721 l.add(ImageTypeSpecifier.createIndexed(red, green, 1722 blue, alpha, 1723 bitDepth, 1724 DataBuffer.TYPE_BYTE)); 1725 break; 1726 1727 case PNG_COLOR_GRAY_ALPHA: 1728 // Component G, A 1729 gray = ColorSpace.getInstance(ColorSpace.CS_GRAY); 1730 bandOffsets = new int[2]; 1731 bandOffsets[0] = 0; 1732 bandOffsets[1] = 1; 1733 l.add(ImageTypeSpecifier.createInterleaved(gray, 1734 bandOffsets, 1735 dataType, 1736 true, 1737 false)); 1738 break; 1739 1740 case PNG_COLOR_RGB_ALPHA: 1741 if (bitDepth == 8) { 1742 // some standard types of buffered images 1743 // wich can be used as destination 1744 l.add(ImageTypeSpecifier.createFromBufferedImageType( 1745 BufferedImage.TYPE_4BYTE_ABGR)); 1746 1747 l.add(ImageTypeSpecifier.createFromBufferedImageType( 1748 BufferedImage.TYPE_INT_ARGB)); 1749 } 1750 1751 // Component R, G, B, A (non-premultiplied) 1752 rgb = ColorSpace.getInstance(ColorSpace.CS_sRGB); 1753 bandOffsets = new int[4]; 1754 bandOffsets[0] = 0; 1755 bandOffsets[1] = 1; 1756 bandOffsets[2] = 2; 1757 bandOffsets[3] = 3; 1758 1759 l.add(ImageTypeSpecifier.createInterleaved(rgb, 1760 bandOffsets, 1761 dataType, 1762 true, 1763 false)); 1764 break; 1765 1766 default: 1767 break; 1768 } 1769 1770 return l.iterator(); 1771 } 1772 1773 /* 1774 * Super class implementation uses first element 1775 * of image types list as raw image type. 1776 * 1777 * Also, super implementation uses first element of this list 1778 * as default destination type image read param does not specify 1779 * anything other. 1780 * 1781 * However, in case of RGB and RGBA color types, raw image type 1782 * produces buffered image of custom type. It causes some 1783 * performance degradation of subsequent rendering operations. 1784 * 1785 * To resolve this contradiction we put standard image types 1786 * at the first positions of image types list (to produce standard 1787 * images by default) and put raw image type (which is custom) 1788 * at the last position of this list. 1789 * 1790 * After this changes we should override getRawImageType() 1791 * to return last element of image types list. 1792 */ 1793 public ImageTypeSpecifier getRawImageType(int imageIndex) 1794 throws IOException { 1795 1796 Iterator<ImageTypeSpecifier> types = getImageTypes(imageIndex); 1797 ImageTypeSpecifier raw = null; 1798 do { 1799 raw = types.next(); 1800 } while (types.hasNext()); 1801 return raw; 1802 } 1803 1804 public ImageReadParam getDefaultReadParam() { 1805 return new ImageReadParam(); 1806 } 1807 1808 public IIOMetadata getStreamMetadata() 1809 throws IIOException { 1810 return null; 1811 } 1812 1813 public IIOMetadata getImageMetadata(int imageIndex) throws IIOException { 1814 if (imageIndex != 0) { 1815 throw new IndexOutOfBoundsException("imageIndex != 0!"); 1816 } 1817 readMetadata(); 1818 return metadata; 1819 } 1820 1821 public BufferedImage read(int imageIndex, ImageReadParam param) 1822 throws IIOException { 1823 if (imageIndex != 0) { 1824 throw new IndexOutOfBoundsException("imageIndex != 0!"); 1825 } 1826 1827 try { 1828 readImage(param); 1829 } catch (IOException | 1830 IllegalStateException | 1831 IllegalArgumentException e) 1832 { 1833 throw e; 1834 } catch (Throwable e) { 1835 throw new IIOException("Caught exception during read: ", e); 1836 } 1837 return theImage; 1838 } 1839 1840 public void reset() { 1841 super.reset(); 1842 resetStreamSettings(); 1843 } 1844 1845 private void resetStreamSettings() { 1846 gotHeader = false; 1847 gotMetadata = false; 1848 metadata = null; 1849 pixelStream = null; 1850 imageStartPosition = -1L; 1851 } 1852 }