JOGL 2.3.2 · jogamp.opengl.util.pngj.PngReader

Modifier and Type	Field and Description
protected final int	buffersLen
private int	bytesChunksLoaded
private ChunkLoadBehaviour	chunkLoadBehaviour
protected final ChunksList	chunksList
private boolean	crcEnabled
protected CRC32	crctest
protected int	currentChunkGroup Current chunk group, (0-6) already read or reading see `ChunksList`
private final PngDeinterlacer	deinterlacer
protected final String	filename not necesarily a filename, can be a description - merely informative
protected InflaterInputStream	idatIstream
protected PngIDatChunkInputStream	iIdatCstream
public final ImageInfo	imgInfo Basic image info - final and inmutable.
protected ImageLine	imgLine
private Inflater	inflater
protected final InputStream	inputStream
private final boolean	interlaced
private int	maxBytesMetadata
private long	maxTotalBytesRead
protected final PngMetadata	metadata
private long	offset
protected byte[]	rowb
protected byte[]	rowbfilter
protected byte[]	rowbprev
protected int	rowNum
private boolean	shouldCloseStream
private String[]	skipChunkIds
private HashSet<String>	skipChunkIdsSet
private int	skipChunkMaxSize
private boolean	unpackedMode

Access	Constructor and Description
public	PngReader(final InputStream inputStream, final String : Optional, can be a filename or a description. Just for error/debug messages filenameOrDescription) Constructs a PngReader from an InputStream.

Method Summary

Modifier and Type	Method and Description
private void	allocateBuffers()
private void	close()
private void	decodeLastReadRowToByte(final byte[] buffer, final int bytesRead)
private void	decodeLastReadRowToInt(final int[] buffer, final int bytesRead)
public void	end() Normally this does nothing, but it can be used to force a premature closing.
private boolean	firstChunksNotYetRead()
public ChunkLoadBehaviour	getChunkLoadBehaviour()
public ChunksList	getChunksList() All loaded chunks (metada).
pack-priv long	Returns: CRC of the raw pixels values getCrctestVal() Just for testing.
pack-priv int	getCurrentChunkGroup()
public int	Returns: Total maximum bytes to load from ancillary ckunks. getMaxBytesMetadata()
public long	Returns: Total maximum bytes to read. getMaxTotalBytesRead()
public PngMetadata	getMetadata() High level wrapper over chunksList
public ImageLine	getRow(final int nrow) Deprecated Now `readRow(int)` implements the same funcion. This method will be removed in future releases
public String[]	Returns: Chunk-IDs to be skipped. getSkipChunkIds()
public int	Returns: maximum size in bytes for individual ancillary chunks. getSkipChunkMaxSize()
pack-priv void	initCrctest() Inits CRC object and enables CRC calculation
public boolean	isInterlaced() Interlaced PNG is accepted -though not welcomed- now...
public boolean	isUnpackedMode()
protected void	logWarn(final String warn) Logs/prints a warning.
private PngChunk	readChunk(final byte[] chunkid, final int clen, final boolean skipforced) Reads chunkd from input stream, adds to ChunksList, and returns it.
private final void	readFirstChunks() Reads chunks before first IDAT.
private void	readLastAndClose() Reads last Internally called after having read the last line.
pack-priv void	readLastChunks() Reads (and processes) chunks after last IDAT.
public ImageLine	readRow(final int nrow) If called for first time, calls readRowInt.
public final int[]	readRow(final int[] buffer, final int nrow)
public ImageLine	Returns: ImageLine object, also available as field. Data is in `ImageLine#scanlineb` (byte) field. readRowByte(final int Row number, from 0 to rows-1. Increasing order. nrow) Reads the row as BYTES, storing it in the `imgLine` property and returning it.
public final byte[]	Returns: The scanline in the same passwd buffer if it was allocated, a newly allocated one otherwise readRowByte(byte[] Prealocated buffer, or null. buffer, final int Row number (0 is top). Most be strictly greater than the last read row. nrow) Reads a line and returns it as a byte[] array.
public ImageLine	Returns: ImageLine object, also available as field. Data is in `ImageLine#scanline` (int) field. readRowInt(final int Row number, from 0 to rows-1. Increasing order. nrow) Reads the row as INT, storing it in the `imgLine` property and returning it.
public final int[]	Returns: The scanline in the same passwd buffer if it was allocated, a newly allocated one otherwise readRowInt(int[] Prealocated buffer, or null. buffer, final int Row number (0 is top). Most be strictly greater than the last read row. nrow) Reads a line and returns it as a int[] array.
private int	readRowRaw(final int nrow)
public ImageLines	Returns: Set of lines as a matrix readRowsByte(final int Number of rows to be skipped rowOffset, int Total number of rows to be read. -1: read all available nRows, final int Row increment. If 1, we read consecutive lines; if 2, we read even/odd lines, etc rowStep) Reads a set of lines and returns it as a ImageLines object, which wrapas a byte[][] matrix.
public ImageLines	readRowsByte() Same as readRowsByte(0, imgInfo.rows, 1)
public ImageLines	Returns: Set of lines as a ImageLines, which wraps a matrix readRowsInt(final int Number of rows to be skipped rowOffset, int Total number of rows to be read. -1: read all available nRows, final int Row increment. If 1, we read consecutive lines; if 2, we read even/odd lines, etc rowStep) Reads a set of lines and returns it as a ImageLines object, which wraps matrix.
public ImageLines	readRowsInt() Same as readRowsInt(0, imgInfo.rows, 1)
public void	readSkippingAllRows() Reads all the (remaining) file, skipping the pixels data.
public void	reuseBuffersFrom(final PngReader A PngReader that has already finished reading pixels. Can be null. other) Tries to reuse the allocated buffers from other already used PngReader object.
public void	setChunkLoadBehaviour(final ChunkLoadBehaviour `ChunkLoadBehaviour` chunkLoadBehaviour) Determines which ancillary chunks (metada) are to be loaded
public void	setCrcCheckDisabled() Disables the CRC integrity check in IDAT chunks and ancillary chunks, this gives a slight increase in reading speed for big files
public void	setMaxBytesMetadata(final int maxBytesChunksToLoad) Set total maximum bytes to load from ancillary chunks (0: unlimited; default: 5Mb).
public void	setMaxTotalBytesRead(final long maxTotalBytesToRead) Set total maximum bytes to read (0: unlimited; default: 200MB).
public void	setShouldCloseStream(final boolean shouldCloseStream) if true, input stream will be closed after ending read default=true
public void	setSkipChunkIds(final String[] skipChunksById) Chunks ids to be skipped.
public void	setSkipChunkMaxSize(final int skipChunksBySize) Set maximum size in bytes for individual ancillary chunks (0: unlimited; default: 2MB).
public void	setUnpackedMode(final boolean unPackedMode) set/unset "unpackedMode" If false (default) packed types (bitdepth=1,2 or 4) will keep several samples packed in one element (byte or int) If true, samples will be unpacked on reading, and each element in the scanline will be sample.
public String	toString() Overrides java.lang.Object.toString. Basic info, for debugging.
private void	unfilterRow(final int nbytes)
private void	unfilterRowAverage(final int nbytes)
private void	unfilterRowNone(final int nbytes)
private void	unfilterRowPaeth(final int nbytes)
private void	unfilterRowSub(final int nbytes)
private void	unfilterRowUp(final int nbytes)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll wait wait wait

buffersLen	back to summary
protected final int buffersLen

bytesChunksLoaded	back to summary
private int bytesChunksLoaded

chunkLoadBehaviour	back to summary
private ChunkLoadBehaviour chunkLoadBehaviour

chunksList	back to summary
protected final ChunksList chunksList

crcEnabled	back to summary
private boolean crcEnabled

crctest	back to summary
protected CRC32 crctest

currentChunkGroup	back to summary
protected int currentChunkGroup Current chunk group, (0-6) already read or reading see `ChunksList`

deinterlacer	back to summary
private final PngDeinterlacer deinterlacer

filename	back to summary
protected final String filename not necesarily a filename, can be a description - merely informative

idatIstream	back to summary
protected InflaterInputStream idatIstream

iIdatCstream	back to summary
protected PngIDatChunkInputStream iIdatCstream

imgInfo	back to summary
public final ImageInfo imgInfo Basic image info - final and inmutable.

imgLine	back to summary
protected ImageLine imgLine

inflater	back to summary
private Inflater inflater

inputStream	back to summary
protected final InputStream inputStream

interlaced	back to summary
private final boolean interlaced

maxTotalBytesRead	back to summary
private long maxTotalBytesRead

offset	back to summary
private long offset

rowb	back to summary
protected byte[] rowb

rowbfilter	back to summary
protected byte[] rowbfilter

rowbprev	back to summary
protected byte[] rowbprev

rowNum	back to summary
protected int rowNum

shouldCloseStream	back to summary
private boolean shouldCloseStream

skipChunkIds	back to summary
private String[] skipChunkIds

skipChunkIdsSet	back to summary
private HashSet<String> skipChunkIdsSet

skipChunkMaxSize	back to summary
private int skipChunkMaxSize

unpackedMode	back to summary
private boolean unpackedMode

PngReader	back to summary
public PngReader(final InputStream inputStream, final String filenameOrDescription) Constructs a PngReader from an InputStream. See also `FileHelper.createPngReader(File f)` if available. Reads only the signature and first chunk (IDHR) Parameters filenameOrDescription:String : Optional, can be a filename or a description. Just for error/debug messages

Method Detail

allocateBuffers	back to summary
private void allocateBuffers()

close	back to summary
private void close()

decodeLastReadRowToByte	back to summary
private void decodeLastReadRowToByte(final byte[] buffer, final int bytesRead)

decodeLastReadRowToInt	back to summary
private void decodeLastReadRowToInt(final int[] buffer, final int bytesRead)

end	back to summary
public void end() Normally this does nothing, but it can be used to force a premature closing. Its recommended practice to call it after reading the image pixels.

firstChunksNotYetRead	back to summary
private boolean firstChunksNotYetRead()

getChunkLoadBehaviour	back to summary
public ChunkLoadBehaviour getChunkLoadBehaviour() See Also `setChunkLoadBehaviour(ChunkLoadBehaviour)`

getChunksList back to summary

getChunksList	back to summary
public ChunksList getChunksList() All loaded chunks (metada). If we have not yet end reading the image, this will include only the chunks before the pixels data (IDAT) Critical chunks are included, except that all IDAT chunks appearance are replaced by a single dummy-marker IDAT chunk. These might be copied to the PngWriter See Also `getMetadata()`

public ChunksList getChunksList()

All loaded chunks (metada). If we have not yet end reading the image, this will include only the chunks before the pixels data (IDAT)

Critical chunks are included, except that all IDAT chunks appearance are replaced by a single dummy-marker IDAT chunk. These might be copied to the PngWriter

See Also: getMetadata()

getCrctestVal	back to summary
pack-priv long getCrctestVal() Just for testing. TO be called after ending reading, only if initCrctest() was called before start Returns:long CRC of the raw pixels values

getCrctestVal

back to summary

pack-priv long getCrctestVal()

Just for testing. TO be called after ending reading, only if initCrctest() was called before start

Returns:long: CRC of the raw pixels values

getCurrentChunkGroup	back to summary
pack-priv int getCurrentChunkGroup()

getMaxBytesMetadata	back to summary
public int getMaxBytesMetadata() Returns:int Total maximum bytes to load from ancillary ckunks.

getMaxTotalBytesRead	back to summary
public long getMaxTotalBytesRead() Returns:long Total maximum bytes to read.

getMetadata back to summary

public PngMetadata getMetadata()

High level wrapper over chunksList

See Also: getChunksList()

getRow	back to summary
public ImageLine getRow(final int nrow) Deprecated Now `readRow(int)` implements the same funcion. This method will be removed in future releases

getSkipChunkIds	back to summary
public String[] getSkipChunkIds() Returns:String[] Chunk-IDs to be skipped.

getSkipChunkMaxSize	back to summary
public int getSkipChunkMaxSize() Returns:int maximum size in bytes for individual ancillary chunks.

initCrctest	back to summary
pack-priv void initCrctest() Inits CRC object and enables CRC calculation

isInterlaced	back to summary
public boolean isInterlaced() Interlaced PNG is accepted -though not welcomed- now...

isUnpackedMode	back to summary
public boolean isUnpackedMode() See Also `PngReader#setUnpackedMode(boolean)`

logWarn

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protected void logWarn(final String warn)

Logs/prints a warning.

The default behaviour is print to stderr, but it can be overriden.

This happens rarely - most errors are fatal.

readChunk	back to summary
private PngChunk readChunk(final byte[] chunkid, final int clen, final boolean skipforced) Reads chunkd from input stream, adds to ChunksList, and returns it. If it's skipped, a PngChunkSkipped object is created

readFirstChunks

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private final void readFirstChunks()

Reads chunks before first IDAT. Normally this is called automatically

Position before: after IDHR (crc included) Position after: just after the first IDAT chunk id

This can be called several times (tentatively), it does nothing if already run

(Note: when should this be called? in the constructor? hardly, because we loose the opportunity to call setChunkLoadBehaviour() and perhaps other settings before reading the first row? but sometimes we want to access some metadata (plte, phys) before. Because of this, this method can be called explicitly but is also called implicititly in some methods (getMetatada(), getChunksList())

readLastAndClose	back to summary
private void readLastAndClose() Reads last Internally called after having read the last line. It reads extra chunks after IDAT, if present.

readLastChunks	back to summary
pack-priv void readLastChunks() Reads (and processes) chunks after last IDAT.

readRow back to summary

public ImageLine readRow(final int nrow)

If called for first time, calls readRowInt. Elsewhere, it calls the appropiate readRowInt/readRowByte

In general, specifying the concrete readRowInt/readRowByte is preferrable

See Also: <a href="jogamp.opengl.util.pngj.PngReader.html#readRowByte-int-" class="jlink"><code class="coderef">readRowByte(int)</code></a>

readRow	back to summary
public final int[] readRow(final int[] buffer, final int nrow) See Also `readRowInt(int[], int)`

readRowByte back to summary

public ImageLine readRowByte(final int nrow)

Reads the row as BYTES, storing it in the imgLine property and returning it. The row must be greater or equal than the last read row. This method allows to pass the same row that was last read.

Parameters

nrow:int: Row number, from 0 to rows-1. Increasing order.

Returns:ImageLine

ImageLine object, also available as field. Data is in ImageLine#scanlineb (byte) field.

readRowByte back to summary

public final byte[] readRowByte(byte[] buffer, final int nrow)

Reads a line and returns it as a byte[] array.

You can pass (optionally) a prealocatted buffer.

If the bitdepth is less than 8, the bytes are packed - unless unpackedMode is true.
If the bitdepth is 16, the least significant byte is lost.

Parameters

buffer:byte[]: Prealocated buffer, or null.
nrow:int: Row number (0 is top). Most be strictly greater than the last read row.

Returns:byte[]

The scanline in the same passwd buffer if it was allocated, a newly allocated one otherwise

readRowInt back to summary

public ImageLine readRowInt(final int nrow)

Reads the row as INT, storing it in the imgLine property and returning it. The row must be greater or equal than the last read row.

Parameters

nrow:int: Row number, from 0 to rows-1. Increasing order.

Returns:ImageLine

ImageLine object, also available as field. Data is in ImageLine#scanline (int) field.

readRowInt back to summary

public final int[] readRowInt(int[] buffer, final int nrow)

Reads a line and returns it as a int[] array.

You can pass (optionally) a prealocatted buffer.

If the bitdepth is less than 8, the bytes are packed - unless unpackedMode is true.

Parameters

buffer:int[]: Prealocated buffer, or null.
nrow:int: Row number (0 is top). Most be strictly greater than the last read row.

Returns:int[]

The scanline in the same passwd buffer if it was allocated, a newly allocated one otherwise

readRowRaw	back to summary
private int readRowRaw(final int nrow)

readRowsByte back to summary

public ImageLines readRowsByte(final int rowOffset, int nRows, final int rowStep)

Reads a set of lines and returns it as a ImageLines object, which wrapas a byte[][] matrix. Internally it reads all lines, but decodes and stores only the wanted ones. This starts and ends the reading, and cannot be combined with other reading methods.

This it's more efficient (speed an memory) that doing calling readRowByte() for each desired line only if the image is interlaced.

Notice that the columns in the matrix is not the pixel width of the image, but rather pixels x channels

Parameters

rowOffset:int: Number of rows to be skipped
nRows:int: Total number of rows to be read. -1: read all available
rowStep:int: Row increment. If 1, we read consecutive lines; if 2, we read even/odd lines, etc

Returns:ImageLines

Set of lines as a matrix

readRowsByte back to summary

public ImageLines readRowsByte()

Same as readRowsByte(0, imgInfo.rows, 1)

See Also: readRowsByte(int, int, int)

readRowsInt back to summary

public ImageLines readRowsInt(final int rowOffset, int nRows, final int rowStep)

Reads a set of lines and returns it as a ImageLines object, which wraps matrix. Internally it reads all lines, but decodes and stores only the wanted ones. This starts and ends the reading, and cannot be combined with other reading methods.

This it's more efficient (speed an memory) that doing calling readRowInt() for each desired line only if the image is interlaced.

Notice that the columns in the matrix is not the pixel width of the image, but rather pixels x channels

Parameters

rowOffset:int: Number of rows to be skipped
nRows:int: Total number of rows to be read. -1: read all available
rowStep:int: Row increment. If 1, we read consecutive lines; if 2, we read even/odd lines, etc

Returns:ImageLines

Set of lines as a ImageLines, which wraps a matrix

See Also

to read about the format of each row

readRowsInt back to summary

public ImageLines readRowsInt()

Same as readRowsInt(0, imgInfo.rows, 1)

See Also: readRowsInt(int, int, int)

readSkippingAllRows	back to summary
public void readSkippingAllRows() Reads all the (remaining) file, skipping the pixels data. This is much more efficient that calling readRow(), specially for big files (about 10 times faster!), because it doesn't even decompress the IDAT stream and disables CRC check Use this if you are not interested in reading pixels,only metadata.

reuseBuffersFrom

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public void reuseBuffersFrom(final PngReader other)

Tries to reuse the allocated buffers from other already used PngReader object. This will have no effect if the buffers are smaller than necessary. It also reuses the inflater.

Parameters

other:PngReader: A PngReader that has already finished reading pixels. Can be null.

setChunkLoadBehaviour back to summary

public void setChunkLoadBehaviour(final ChunkLoadBehaviour chunkLoadBehaviour)

Determines which ancillary chunks (metada) are to be loaded

Parameters

chunkLoadBehaviour:ChunkLoadBehaviour: ChunkLoadBehaviour

setCrcCheckDisabled	back to summary
public void setCrcCheckDisabled() Disables the CRC integrity check in IDAT chunks and ancillary chunks, this gives a slight increase in reading speed for big files

setMaxBytesMetadata	back to summary
public void setMaxBytesMetadata(final int maxBytesChunksToLoad) Set total maximum bytes to load from ancillary chunks (0: unlimited; default: 5Mb). If exceeded, some chunks will be skipped

setMaxTotalBytesRead	back to summary
public void setMaxTotalBytesRead(final long maxTotalBytesToRead) Set total maximum bytes to read (0: unlimited; default: 200MB). These are the bytes read (not loaded) in the input stream. If exceeded, an exception will be thrown.

setShouldCloseStream

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public void setShouldCloseStream(final boolean shouldCloseStream)

if true, input stream will be closed after ending read

default=true

setSkipChunkIds	back to summary
public void setSkipChunkIds(final String[] skipChunksById) Chunks ids to be skipped. These chunks will be skipped (the CRC will not be checked) and the chunk will be saved as a PngChunkSkipped object. See also setSkipChunkMaxSize

setSkipChunkMaxSize	back to summary
public void setSkipChunkMaxSize(final int skipChunksBySize) Set maximum size in bytes for individual ancillary chunks (0: unlimited; default: 2MB). Chunks exceeding this length will be skipped (the CRC will not be checked) and the chunk will be saved as a PngChunkSkipped object. See also setSkipChunkIds

setUnpackedMode

back to summary

public void setUnpackedMode(final boolean unPackedMode)

set/unset "unpackedMode"
If false (default) packed types (bitdepth=1,2 or 4) will keep several samples packed in one element (byte or int)
If true, samples will be unpacked on reading, and each element in the scanline will be sample. This implies more processing and memory, but it's the most efficient option if you intend to read individual pixels.
This option should only be set before start reading.

toString

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public String toString()

Overrides java.lang.Object.toString.

Basic info, for debugging.

Returns:String

Doc from java.lang.Object.toString.

a string representation of the object

Annotations

@Override

unfilterRow	back to summary
private void unfilterRow(final int nbytes)

unfilterRowAverage	back to summary
private void unfilterRowAverage(final int nbytes)

unfilterRowNone	back to summary
private void unfilterRowNone(final int nbytes)

unfilterRowPaeth	back to summary
private void unfilterRowPaeth(final int nbytes)

unfilterRowSub	back to summary
private void unfilterRowSub(final int nbytes)

unfilterRowUp	back to summary
private void unfilterRowUp(final int nbytes)

public Class PngReader

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail