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Merge pull request #371 from Schmidor/ccittbytealigned

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Support PDF ByteAligned Flag on CCITT Decoder
This commit is contained in:
Harald Kuhr 2017-08-21 21:43:24 +02:00 committed by GitHub
commit 2d564ad98e
2 changed files with 43 additions and 12 deletions
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36
imageio/imageio-tiff/src/main/java/com/twelvemonkeys/imageio/plugins/tiff/CCITTFaxDecoderStream.java
View File

@ -71,6 +71,8 @@ final class CCITTFaxDecoderStream extends FilterInputStream {
private boolean optionUncompressed = false;
private boolean optionByteAligned = false;
public CCITTFaxDecoderStream(final InputStream stream, final int columns, final int type, final int fillOrder,
final long options) {
super(Validate.notNull(stream, "stream"));
@ -92,6 +94,9 @@ final class CCITTFaxDecoderStream extends FilterInputStream {
this.changesCurrentRow = new int[columns + 2];
switch (type) {
case TIFFBaseline.COMPRESSION_CCITT_MODIFIED_HUFFMAN_RLE:
optionByteAligned = true;
break;
case TIFFExtension.COMPRESSION_CCITT_T4:
optionG32D = (options & TIFFExtension.GROUP3OPT_2DENCODING) != 0;
optionG3Fill = (options & TIFFExtension.GROUP3OPT_FILLBITS) != 0;
@ -106,6 +111,15 @@ final class CCITTFaxDecoderStream extends FilterInputStream {
"CCITT GROUP 3/4 OPTION UNCOMPRESSED is not supported");
}
/**
* This is used for CCITT streams from PDF files, which use EncodedByteAlign
*
* @param enable enable byte alignment
*/
public void setOptionByteAligned(boolean enable) {
optionByteAligned = enable;
}
private void fetch() throws IOException {
if (decodedPos >= decodedLength) {
decodedLength = 0;
@ -241,11 +255,16 @@ final class CCITTFaxDecoderStream extends FilterInputStream {
}
private void decodeRowType2() throws IOException {
resetBuffer();
if (optionByteAligned) {
resetBuffer();
}
decode1D();
}
private void decodeRowType4() throws IOException {
if (optionByteAligned) {
resetBuffer();
}
eof: while (true) {
// read till next EOL code
Node n = eolOnlyTree.root;
@ -272,6 +291,9 @@ final class CCITTFaxDecoderStream extends FilterInputStream {
}
private void decodeRowType6() throws IOException {
if (optionByteAligned) {
resetBuffer();
}
decode2D();
}
@ -369,17 +391,7 @@ final class CCITTFaxDecoderStream extends FilterInputStream {
}
private void resetBuffer() throws IOException {
for (int i = 0; i < decodedRow.length; i++) {
decodedRow[i] = 0;
}
while (true) {
if (bufferPos == -1) {
return;
}
readBit();
}
bufferPos = -1;
}
int buffer = -1;

19
imageio/imageio-tiff/src/test/java/com/twelvemonkeys/imageio/plugins/tiff/CCITTFaxDecoderStreamTest.java
View File

@ -74,6 +74,13 @@ public class CCITTFaxDecoderStreamTest {
// Line 4: V-1, V0, V0 EOL EOL
static final byte[] DATA_G4 = { 0x04, 0x17, (byte) 0xF5, (byte) 0x80, 0x08, 0x00, (byte) 0x80 };
static final byte[] DATA_G4_ALIGNED = {
0x04, 0x14, // 00000100 000101(00)
(byte) 0xE0, // 111 (00000)
(byte) 0xE0, // 111 (00000)
0x58 // 01011 (000)
};
// TODO: Better tests (full A4 width scan lines?)
// From http://www.mikekohn.net/file_formats/tiff.php
@ -262,6 +269,18 @@ public class CCITTFaxDecoderStreamTest {
assertEquals((byte) 0b10101010, decoded);
}
@Test
public void testDecodeType4ByteAligned() throws IOException {
CCITTFaxDecoderStream stream = new CCITTFaxDecoderStream(new ByteArrayInputStream(DATA_G4_ALIGNED), 6,
TIFFExtension.COMPRESSION_CCITT_T6, 1, 0L);
stream.setOptionByteAligned(true);
byte[] imageData = ((DataBufferByte) image.getData().getDataBuffer()).getData();
byte[] bytes = new byte[imageData.length];
new DataInputStream(stream).readFully(bytes);
assertArrayEquals(imageData, bytes);
}
@Test
public void testG3AOE() throws IOException {
InputStream inputStream = getClass().getResourceAsStream("/tiff/ccitt/g3aoe.tif");