Class PngImage

java.lang.Object

com.itextpdf.text.pdf.codec.PngImage

public class PngImage
extends Object

Reads a PNG image. All types of PNG can be read.

It is based in part in the JAI codec.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	PngImage.NewByteArrayOutputStream

Field Summary

Fields

Modifier and Type	Field	Description
(package private) PdfDictionary	additional
(package private) int	bitDepth
(package private) int	bytesPerPixel
static final String	cHRM	A PNG marker.
(package private) byte[]	colorTable
(package private) int	colorType
(package private) int	compressionMethod
(package private) DataInputStream	dataStream
(package private) int	dpiX
(package private) int	dpiY
(package private) int	filterMethod
static final String	gAMA	A PNG marker.
(package private) float	gamma
(package private) boolean	genBWMask
(package private) boolean	hasCHRM
(package private) int	height
(package private) ICC_Profile	icc_profile
static final String	iCCP	A PNG marker.
(package private) PngImage.NewByteArrayOutputStream	idat
static final String	IDAT	A PNG marker.
static final String	IEND	A PNG marker.
static final String	IHDR	A PNG marker.
(package private) byte[]	image
(package private) int	inputBands
(package private) PdfName	intent
private static final PdfName[]	intents
(package private) int	interlaceMethod
(package private) InputStream	is
(package private) boolean	palShades
static final String	pHYs	A PNG marker.
static final String	PLTE	A PNG marker.
private static final int	PNG_FILTER_AVERAGE
private static final int	PNG_FILTER_NONE
private static final int	PNG_FILTER_PAETH
private static final int	PNG_FILTER_SUB
private static final int	PNG_FILTER_UP
static final int[]	PNGID	Some PNG specific values.
(package private) byte[]	smask
static final String	sRGB	A PNG marker.
(package private) byte[]	trans
(package private) int	transBlue
private static final int	TRANSFERSIZE
(package private) int	transGreen
(package private) int	transRedGray
static final String	tRNS	A PNG marker.
(package private) int	width
(package private) float	xB
(package private) float	xG
(package private) float	xR
(package private) float	xW
(package private) float	XYRatio
(package private) float	yB
(package private) float	yG
(package private) float	yR
(package private) float	yW

Constructor Summary

Constructors

Constructor	Description
PngImage(InputStream is)	Creates a new instance of PngImage

Method Summary

Modifier and Type	Method	Description
private void	checkIccProfile()
(package private) boolean	checkMarker(String s)
private static void	decodeAverageFilter(byte[] curr, byte[] prev, int count, int bpp)
(package private) void	decodeIdat()
private static void	decodePaethFilter(byte[] curr, byte[] prev, int count, int bpp)
(package private) void	decodePass(int xOffset, int yOffset, int xStep, int yStep, int passWidth, int passHeight)
private static void	decodeSubFilter(byte[] curr, int count, int bpp)
private static void	decodeUpFilter(byte[] curr, byte[] prev, int count)
(package private) PdfObject	getColorspace()
private int	getExpectedIccNumberOfComponents()
(package private) Image	getImage()
static Image	getImage(byte[] data)	Reads a PNG from a byte array.
static Image	getImage(InputStream is)	Reads a PNG from a stream.
static Image	getImage(String file)	Reads a PNG from a file.
static Image	getImage(URL url)	Reads a PNG from an url.
static final int	getInt(InputStream is)	Gets an int from an InputStream.
(package private) int[]	getPixel(byte[] curr)
(package private) static int	getPixel(byte[] image, int x, int y, int bitDepth, int bytesPerRow)
static final String	getString(InputStream is)	Gets a String from an InputStream.
static final int	getWord(InputStream is)	Gets a word from an InputStream.
private static int	paethPredictor(int a, int b, int c)
(package private) void	processPixels(byte[] curr, int xOffset, int step, int y, int width)
(package private) void	readPng()
(package private) static void	setPixel(byte[] image, int[] data, int offset, int size, int x, int y, int bitDepth, int bytesPerRow)

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

PNGID

public static final int[] PNGID

Some PNG specific values.

IHDR

public static final String IHDR

A PNG marker.

See Also:

• Constant Field Values

PLTE

public static final String PLTE

A PNG marker.

See Also:

• Constant Field Values

IDAT

public static final String IDAT

A PNG marker.

See Also:

• Constant Field Values

IEND

public static final String IEND

A PNG marker.

See Also:

• Constant Field Values

tRNS

public static final String tRNS

A PNG marker.

See Also:

• Constant Field Values

pHYs

public static final String pHYs

A PNG marker.

See Also:

• Constant Field Values

gAMA

public static final String gAMA

A PNG marker.

See Also:

• Constant Field Values

cHRM

public static final String cHRM

A PNG marker.

See Also:

• Constant Field Values

sRGB

public static final String sRGB

A PNG marker.

See Also:

• Constant Field Values

iCCP

public static final String iCCP

A PNG marker.

See Also:

• Constant Field Values

TRANSFERSIZE

private static final int TRANSFERSIZE

See Also:

• Constant Field Values

PNG_FILTER_NONE

private static final int PNG_FILTER_NONE

See Also:

• Constant Field Values

PNG_FILTER_SUB

private static final int PNG_FILTER_SUB

See Also:

• Constant Field Values

PNG_FILTER_UP

private static final int PNG_FILTER_UP

See Also:

• Constant Field Values

PNG_FILTER_AVERAGE

private static final int PNG_FILTER_AVERAGE

See Also:

• Constant Field Values

PNG_FILTER_PAETH

private static final int PNG_FILTER_PAETH

See Also:

• Constant Field Values

intents

private static final PdfName[] intents

is

InputStream is

dataStream

DataInputStream dataStream

width

int width

height

int height

bitDepth

int bitDepth

colorType

int colorType

compressionMethod

int compressionMethod

filterMethod

int filterMethod

interlaceMethod

int interlaceMethod

additional

PdfDictionary additional

image

byte[] image

smask

byte[] smask

trans

byte[] trans

idat

PngImage.NewByteArrayOutputStream idat

dpiX

int dpiX

dpiY

int dpiY

XYRatio

float XYRatio

genBWMask

boolean genBWMask

palShades

boolean palShades

transRedGray

int transRedGray

transGreen

int transGreen

transBlue

int transBlue

inputBands

int inputBands

bytesPerPixel

int bytesPerPixel

colorTable

byte[] colorTable

gamma

float gamma

hasCHRM

boolean hasCHRM

xW

float xW

yW

float yW

xR

float xR

yR

float yR

xG

float xG

yG

float yG

xB

float xB

yB

float yB

intent

PdfName intent

icc_profile

ICC_Profile icc_profile

Constructor Details

PngImage

PngImage(InputStream is)

Creates a new instance of PngImage

Method Details

getImage

public static Image getImage(URL url)
                      throws IOException

Reads a PNG from an url.

Parameters:

url - the url

Returns:

the image

Throws:

IOException - on error

getImage

public static Image getImage(InputStream is)
                      throws IOException

Reads a PNG from a stream.

Parameters:

is - the stream

Returns:

the image

Throws:

IOException - on error

getImage

public static Image getImage(String file)
                      throws IOException

Reads a PNG from a file.

Parameters:

file - the file

Returns:

the image

Throws:

IOException - on error

getImage

public static Image getImage(byte[] data)
                      throws IOException

Reads a PNG from a byte array.

Parameters:

data - the byte array

Returns:

the image

Throws:

IOException - on error

checkMarker

boolean checkMarker(String s)

readPng

void readPng()
      throws IOException

Throws:

IOException

getColorspace

PdfObject getColorspace()

getImage

Image getImage()
        throws IOException

Throws:

IOException

decodeIdat

void decodeIdat()

decodePass

void decodePass(int xOffset,
 int yOffset,
 int xStep,
 int yStep,
 int passWidth,
 int passHeight)

processPixels

void processPixels(byte[] curr,
 int xOffset,
 int step,
 int y,
 int width)

getPixel

static int getPixel(byte[] image,
 int x,
 int y,
 int bitDepth,
 int bytesPerRow)

setPixel

static void setPixel(byte[] image,
 int[] data,
 int offset,
 int size,
 int x,
 int y,
 int bitDepth,
 int bytesPerRow)

getPixel

int[] getPixel(byte[] curr)

getExpectedIccNumberOfComponents

private int getExpectedIccNumberOfComponents()

checkIccProfile

private void checkIccProfile()

decodeSubFilter

private static void decodeSubFilter(byte[] curr,
 int count,
 int bpp)

decodeUpFilter

private static void decodeUpFilter(byte[] curr,
 byte[] prev,
 int count)

decodeAverageFilter

private static void decodeAverageFilter(byte[] curr,
 byte[] prev,
 int count,
 int bpp)

paethPredictor

private static int paethPredictor(int a,
 int b,
 int c)

decodePaethFilter

private static void decodePaethFilter(byte[] curr,
 byte[] prev,
 int count,
 int bpp)

getInt

public static final int getInt(InputStream is)
                        throws IOException

Gets an int from an InputStream.

Parameters:

is - an InputStream

Returns:

the value of an int

Throws:

IOException

getWord

public static final int getWord(InputStream is)
                         throws IOException

Gets a word from an InputStream.

Parameters:

is - an InputStream

Returns:

the value of an int

Throws:

IOException

getString

public static final String getString(InputStream is)
                              throws IOException

Gets a String from an InputStream.

Parameters:

is - an InputStream

Returns:

the value of an int

Throws:

IOException