Class PNGEncodeParam
- All Implemented Interfaces:
Serializable
,Cloneable
,ImageDecodeParam
,ImageEncodeParam
- Direct Known Subclasses:
PNGEncodeParam.Gray
,PNGEncodeParam.Palette
,PNGEncodeParam.RGB
ImageEncodeParam
for encoding images in
the PNG format.
This class is not a committed part of the JAI API. It may be removed or changed in future releases of JAI.
- See Also:
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic class
static class
static class
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected int
protected boolean
static final int
Constant for use with the sRGB chunk.static final int
Constant for use with the sRGB chunk.static final int
Constant for use with the sRGB chunk.static final int
Constant for use with the sRGB chunk.static final int
Constant for use in filtering.static final int
Constant for use in filtering.static final int
Constant for use in filtering.static final int
Constant for use in filtering.static final int
Constant for use in filtering. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
addPrivateChunk
(String type, byte[] data) Adds a private chunk, in binary form, to the list of chunks to be stored with this image.int
filterRow
(byte[] currRow, byte[] prevRow, byte[][] scratchRows, int bytesPerRow, int bytesPerPixel) Performs filtering on a row of an image.int
Returns the desired bit depth for a grayscale image.float[]
Returns the white point and primary chromaticities in CIE (x, y) space.String[]
Returns the text strings to be stored in compressed form with this image as an array ofString
s.static PNGEncodeParam
Returns an instance ofPNGEncodeParam.Palette
,PNGEncodeParam.Gray
, orPNGEncodeParam.RGB
appropriate for encoding the given image.float
getGamma()
Returns the file gamma value for the image.byte[]
Returns the ICC profile data to be stored with this image.boolean
Returnstrue
if Adam7 interlacing will be used.Returns the modification time to be stored with this image.int
Returns the number of private chunks to be written to the output file.int[]
Returns the palette histogram to be stored with this image.int[]
Returns the physical dimension information to be stored with this image.byte[]
getPrivateChunkData
(int index) Returns the data associated of the private chunk at a given index, as an array ofbyte
s.getPrivateChunkType
(int index) Returns the type of the private chunk at a given index, as a 4-characterString
.int[]
Returns the number of significant bits for each band of the image.int
Returns the sRGB rendering intent to be stored with this image.Returns the suggested palette information to be stored with this image.String[]
getText()
Returns the text strings to be stored in uncompressed form with this image as an array ofString
s.boolean
Returns true if a 'bKGD' chunk will be output.boolean
Returns true if a 'cHRM' chunk will be output.boolean
Returns true if a 'zTXT' chunk will be output.boolean
Returns true if a 'gAMA' chunk will be output.boolean
Returns true if a 'iCCP' chunk will be output.boolean
Returns true if a 'tIME' chunk will be output.boolean
Returns true if a 'hIST' chunk will be output.boolean
Returns true if a 'pHYS' chunk will be output.boolean
Returns true if an 'sBIT' chunk will be output.boolean
Returns true if an 'sRGB' chunk will be output.boolean
Returns true if a 'sPLT' chunk will be output.boolean
Returns true if a 'tEXt' chunk will be output.boolean
Returns true if a 'tRNS' chunk will be output.static int
paethPredictor
(int a, int b, int c) The Paeth predictor routine used in PNG encoding.void
Remove all private chunks associated with this parameter instance.void
Remove all private chunks associated with this parameter instance whose 'safe-to-copy' bit is not set.abstract void
setBitDepth
(int bitDepth) Sets the desired bit depth of an image.void
setChromaticity
(float[] chromaticity) Sets the white point and primary chromaticities in CIE (x, y) space.void
setChromaticity
(float whitePointX, float whitePointY, float redX, float redY, float greenX, float greenY, float blueX, float blueY) A convenience method that calls the array version.void
setCompressedText
(String[] text) Sets the text strings to be stored in compressed form with this image.void
setGamma
(float gamma) Sets the file gamma value for the image.void
setICCProfileData
(byte[] iccProfileData) Sets the ICC profile data to be stored with this image.void
setInterlacing
(boolean useInterlacing) Turns Adam7 interlacing on or off.void
setModificationTime
(Date modificationTime) Sets the modification time, as aDate
, to be stored with this image.void
setPaletteHistogram
(int[] paletteHistogram) Sets the palette histogram to be stored with this image.void
setPhysicalDimension
(int[] physicalDimension) Sets the physical dimension information to be stored with this image.void
setPhysicalDimension
(int xPixelsPerUnit, int yPixelsPerUnit, int unitSpecifier) A convenience method that calls the array version.void
setSignificantBits
(int[] significantBits) Sets the number of significant bits for each band of the image.void
setSRGBIntent
(int srgbIntent) Sets the sRGB rendering intent to be stored with this image.void
setSuggestedPalette
(PNGSuggestedPaletteEntry[] palette) Sets the suggested palette information to be stored with this image.void
Sets the textual data to be stored in uncompressed form with this image.void
Suppresses the 'bKGD' chunk from being output.void
Suppresses the setting of the bit depth of a grayscale image.void
Suppresses the 'cHRM' chunk from being output.void
Suppresses the 'zTXt' chunk from being output.void
Suppresses the 'gAMA' chunk from being output.void
Suppresses the 'iCCP' chunk from being output.void
Suppresses the 'tIME' chunk from being output.void
Suppresses the 'hIST' chunk from being output.void
Suppresses the 'pHYS' chunk from being output.void
Suppresses the 'sBIT' chunk from being output.void
Suppresses the 'sRGB' chunk from being output.void
Suppresses the 'sPLT' chunk from being output.void
Suppresses the 'tEXt' chunk from being output.void
Suppresses the 'tRNS' chunk from being output.
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Field Details
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INTENT_PERCEPTUAL
public static final int INTENT_PERCEPTUALConstant for use with the sRGB chunk.- See Also:
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INTENT_RELATIVE
public static final int INTENT_RELATIVEConstant for use with the sRGB chunk.- See Also:
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INTENT_SATURATION
public static final int INTENT_SATURATIONConstant for use with the sRGB chunk.- See Also:
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INTENT_ABSOLUTE
public static final int INTENT_ABSOLUTEConstant for use with the sRGB chunk.- See Also:
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PNG_FILTER_NONE
public static final int PNG_FILTER_NONEConstant for use in filtering.- See Also:
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PNG_FILTER_SUB
public static final int PNG_FILTER_SUBConstant for use in filtering.- See Also:
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PNG_FILTER_UP
public static final int PNG_FILTER_UPConstant for use in filtering.- See Also:
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PNG_FILTER_AVERAGE
public static final int PNG_FILTER_AVERAGEConstant for use in filtering.- See Also:
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PNG_FILTER_PAETH
public static final int PNG_FILTER_PAETHConstant for use in filtering.- See Also:
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bitDepth
protected int bitDepth -
bitDepthSet
protected boolean bitDepthSet
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Constructor Details
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PNGEncodeParam
public PNGEncodeParam()
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Method Details
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getDefaultEncodeParam
Returns an instance ofPNGEncodeParam.Palette
,PNGEncodeParam.Gray
, orPNGEncodeParam.RGB
appropriate for encoding the given image.If the image has an
IndexColorModel
, an instance ofPNGEncodeParam.Palette
is returned. Otherwise, if the image has 1 or 2 bands an instance ofPNGEncodeParam.Gray
is returned. In all other cases an instance ofPNGEncodeParam.RGB
is returned.Note that this method does not provide any guarantee that the given image will be successfully encoded by the PNG encoder, as it only performs a very superficial analysis of the image structure.
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setBitDepth
public abstract void setBitDepth(int bitDepth) Sets the desired bit depth of an image. -
getBitDepth
public int getBitDepth()Returns the desired bit depth for a grayscale image.If the bit depth has not previously been set, or has been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the bit depth is not set.
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unsetBitDepth
public void unsetBitDepth()Suppresses the setting of the bit depth of a grayscale image. The depth of the encoded image will be inferred from the source image bit depth, rounded up to the next power of 2 between 1 and 16. -
setInterlacing
public void setInterlacing(boolean useInterlacing) Turns Adam7 interlacing on or off. -
getInterlacing
public boolean getInterlacing()Returnstrue
if Adam7 interlacing will be used. -
unsetBackground
public void unsetBackground()Suppresses the 'bKGD' chunk from being output. For API compatibility with JAI 1.0, the superclass defines this method to throw aRuntimeException
; accordingly, subclasses must provide their own implementations. -
isBackgroundSet
public boolean isBackgroundSet()Returns true if a 'bKGD' chunk will be output. For API compatibility with JAI 1.0, the superclass defines this method to throw aRuntimeException
; accordingly, subclasses must provide their own implementations. -
setChromaticity
public void setChromaticity(float[] chromaticity) Sets the white point and primary chromaticities in CIE (x, y) space.The
chromaticity
parameter should be afloat
array of length 8 containing the white point X and Y, red X and Y, green X and Y, and blue X and Y values in order.The 'cHRM' chunk will encode this information.
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setChromaticity
public void setChromaticity(float whitePointX, float whitePointY, float redX, float redY, float greenX, float greenY, float blueX, float blueY) A convenience method that calls the array version. -
getChromaticity
public float[] getChromaticity()Returns the white point and primary chromaticities in CIE (x, y) space.See the documentation for the
setChromaticity
method for the format of the returned data.If the chromaticity has not previously been set, or has been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the chromaticity is not set.
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unsetChromaticity
public void unsetChromaticity()Suppresses the 'cHRM' chunk from being output. -
isChromaticitySet
public boolean isChromaticitySet()Returns true if a 'cHRM' chunk will be output. -
setGamma
public void setGamma(float gamma) Sets the file gamma value for the image.The 'gAMA' chunk will encode this information.
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getGamma
public float getGamma()Returns the file gamma value for the image.If the file gamma has not previously been set, or has been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the gamma is not set.
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unsetGamma
public void unsetGamma()Suppresses the 'gAMA' chunk from being output. -
isGammaSet
public boolean isGammaSet()Returns true if a 'gAMA' chunk will be output. -
setPaletteHistogram
public void setPaletteHistogram(int[] paletteHistogram) Sets the palette histogram to be stored with this image. The histogram consists of an array of integers, one per palette entry.The 'hIST' chunk will encode this information.
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getPaletteHistogram
public int[] getPaletteHistogram()Returns the palette histogram to be stored with this image.If the histogram has not previously been set, or has been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the histogram is not set.
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unsetPaletteHistogram
public void unsetPaletteHistogram()Suppresses the 'hIST' chunk from being output. -
isPaletteHistogramSet
public boolean isPaletteHistogramSet()Returns true if a 'hIST' chunk will be output. -
setICCProfileData
public void setICCProfileData(byte[] iccProfileData) Sets the ICC profile data to be stored with this image. The profile is represented in raw binary form.The 'iCCP' chunk will encode this information.
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getICCProfileData
public byte[] getICCProfileData()Returns the ICC profile data to be stored with this image.If the ICC profile has not previously been set, or has been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the ICC profile is not set.
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unsetICCProfileData
public void unsetICCProfileData()Suppresses the 'iCCP' chunk from being output. -
isICCProfileDataSet
public boolean isICCProfileDataSet()Returns true if a 'iCCP' chunk will be output. -
setPhysicalDimension
public void setPhysicalDimension(int[] physicalDimension) Sets the physical dimension information to be stored with this image. The physicalDimension parameter should be a 3-entry array containing the number of pixels per unit in the X direction, the number of pixels per unit in the Y direction, and the unit specifier (0 = unknown, 1 = meters).The 'pHYS' chunk will encode this information.
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setPhysicalDimension
public void setPhysicalDimension(int xPixelsPerUnit, int yPixelsPerUnit, int unitSpecifier) A convenience method that calls the array version. -
getPhysicalDimension
public int[] getPhysicalDimension()Returns the physical dimension information to be stored with this image.If the physical dimension information has not previously been set, or has been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the physical dimension information is not set.
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unsetPhysicalDimension
public void unsetPhysicalDimension()Suppresses the 'pHYS' chunk from being output. -
isPhysicalDimensionSet
public boolean isPhysicalDimensionSet()Returns true if a 'pHYS' chunk will be output. -
setSuggestedPalette
Sets the suggested palette information to be stored with this image. The information is passed to this method as an array ofPNGSuggestedPaletteEntry
objects.The 'sPLT' chunk will encode this information.
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getSuggestedPalette
Returns the suggested palette information to be stored with this image.If the suggested palette information has not previously been set, or has been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the suggested palette information is not set.
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unsetSuggestedPalette
public void unsetSuggestedPalette()Suppresses the 'sPLT' chunk from being output. -
isSuggestedPaletteSet
public boolean isSuggestedPaletteSet()Returns true if a 'sPLT' chunk will be output. -
setSignificantBits
public void setSignificantBits(int[] significantBits) Sets the number of significant bits for each band of the image.The number of entries in the
significantBits
array must be equal to the number of output bands in the image: 1 for a gray image, 2 for gray+alpha, 3 for index or truecolor, and 4 for truecolor+alpha.The 'sBIT' chunk will encode this information.
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getSignificantBits
public int[] getSignificantBits()Returns the number of significant bits for each band of the image.If the significant bits values have not previously been set, or have been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the significant bits values are not set.
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unsetSignificantBits
public void unsetSignificantBits()Suppresses the 'sBIT' chunk from being output. -
isSignificantBitsSet
public boolean isSignificantBitsSet()Returns true if an 'sBIT' chunk will be output. -
setSRGBIntent
public void setSRGBIntent(int srgbIntent) Sets the sRGB rendering intent to be stored with this image. The legal values are 0 = Perceptual, 1 = Relative Colorimetric, 2 = Saturation, and 3 = Absolute Colorimetric. Refer to the PNG specification for information on these values.The 'sRGB' chunk will encode this information.
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getSRGBIntent
public int getSRGBIntent()Returns the sRGB rendering intent to be stored with this image.If the sRGB intent has not previously been set, or has been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the sRGB intent is not set.
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unsetSRGBIntent
public void unsetSRGBIntent()Suppresses the 'sRGB' chunk from being output. -
isSRGBIntentSet
public boolean isSRGBIntentSet()Returns true if an 'sRGB' chunk will be output. -
setText
Sets the textual data to be stored in uncompressed form with this image. The data is passed to this method as an array ofString
s.The 'tEXt' chunk will encode this information.
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getText
Returns the text strings to be stored in uncompressed form with this image as an array ofString
s.If the text strings have not previously been set, or have been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the text strings are not set.
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unsetText
public void unsetText()Suppresses the 'tEXt' chunk from being output. -
isTextSet
public boolean isTextSet()Returns true if a 'tEXt' chunk will be output. -
setModificationTime
Sets the modification time, as aDate
, to be stored with this image. The internal storage format will use UTC regardless of how themodificationTime
parameter was created.The 'tIME' chunk will encode this information.
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getModificationTime
Returns the modification time to be stored with this image.If the bit depth has not previously been set, or has been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the bit depth is not set.
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unsetModificationTime
public void unsetModificationTime()Suppresses the 'tIME' chunk from being output. -
isModificationTimeSet
public boolean isModificationTimeSet()Returns true if a 'tIME' chunk will be output. -
unsetTransparency
public void unsetTransparency()Suppresses the 'tRNS' chunk from being output. -
isTransparencySet
public boolean isTransparencySet()Returns true if a 'tRNS' chunk will be output. -
setCompressedText
Sets the text strings to be stored in compressed form with this image. The data is passed to this method as an array ofString
s.The 'zTXt' chunk will encode this information.
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getCompressedText
Returns the text strings to be stored in compressed form with this image as an array ofString
s.If the compressed text strings have not previously been set, or have been unset, an
IllegalStateException
will be thrown.- Throws:
IllegalStateException
- if the compressed text strings are not set.
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unsetCompressedText
public void unsetCompressedText()Suppresses the 'zTXt' chunk from being output. -
isCompressedTextSet
public boolean isCompressedTextSet()Returns true if a 'zTXT' chunk will be output. -
addPrivateChunk
Adds a private chunk, in binary form, to the list of chunks to be stored with this image.- Parameters:
type
- a 4-character String giving the chunk type name.data
- an array ofbyte
s containing the chunk data.
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getNumPrivateChunks
public int getNumPrivateChunks()Returns the number of private chunks to be written to the output file. -
getPrivateChunkType
Returns the type of the private chunk at a given index, as a 4-characterString
. The index must be smaller than the return value ofgetNumPrivateChunks
. -
getPrivateChunkData
public byte[] getPrivateChunkData(int index) Returns the data associated of the private chunk at a given index, as an array ofbyte
s. The index must be smaller than the return value ofgetNumPrivateChunks
. -
removeUnsafeToCopyPrivateChunks
public void removeUnsafeToCopyPrivateChunks()Remove all private chunks associated with this parameter instance whose 'safe-to-copy' bit is not set. This may be advisable when transcoding PNG images. -
removeAllPrivateChunks
public void removeAllPrivateChunks()Remove all private chunks associated with this parameter instance. -
paethPredictor
public static int paethPredictor(int a, int b, int c) The Paeth predictor routine used in PNG encoding. This routine is included as a convenience to subclasses that override thefilterRow
method. -
filterRow
public int filterRow(byte[] currRow, byte[] prevRow, byte[][] scratchRows, int bytesPerRow, int bytesPerPixel) Performs filtering on a row of an image. This method may be overridden in order to provide a custom algorithm for choosing the filter type for a given row.The method is supplied with the current and previous rows of the image. For the first row of the image, or of an interlacing pass, the previous row array will be filled with zeros as required by the PNG specification.
The method is also supplied with five scratch arrays. These arrays may be used within the method for any purpose. At method exit, the array at the index given by the return value of the method should contain the filtered data. The return value will also be used as the filter type.
The default implementation of the method performs a trial encoding with each of the filter types, and computes the sum of absolute values of the differences between the raw bytes of the current row and the predicted values. The index of the filter producing the smallest result is returned.
As an example, to perform only 'sub' filtering, this method could be implemented (non-optimally) as follows:
for (int i = bytesPerPixel; i < bytesPerRow + bytesPerPixel; i++) { int curr = currRow[i] & 0xff; int left = currRow[i - bytesPerPixel] & 0xff; scratchRow[PNG_FILTER_SUB][i] = (byte)(curr - left); } return PNG_FILTER_SUB;
- Parameters:
currRow
- The current row as an array ofbyte
s of length at leastbytesPerRow + bytesPerPixel
. The pixel data starts at indexbytesPerPixel
; the initialbytesPerPixel
bytes are zero.prevRow
- The current row as an array ofbyte
s The pixel data starts at indexbytesPerPixel
; the initialbytesPerPixel
bytes are zero.scratchRows
- An array of 5byte
arrays of length at leastbytesPerRow + bytesPerPixel
, useable to hold temporary results. The filtered row will be returned as one of the entries of this array. The returned filtered data should start at indexbytesPerPixel
; The initialbytesPerPixel
bytes are not used.bytesPerRow
- The number of bytes in the image row. This value will always be greater than 0.bytesPerPixel
- The number of bytes representing a single pixel, rounded up to an integer. This is the 'bpp' parameter described in the PNG specification.- Returns:
- The filter type to be used. The entry of
scratchRows[]
at this index holds the filtered data.
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