java.lang.Object
- com.aowagie.text.pdf.codec.PngImage

```
public class PngImage
extends java.lang.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

private static class PngImage.NewByteArrayOutputStream

Field Summary

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

Constructor Summary

Constructors
Modifier Constructor Description

private PngImage(java.io.InputStream is)
Creates a new instance of PngImage

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`private boolean`	`checkMarker(java.lang.String s)`
`private static void`	`decodeAverageFilter(byte[] curr, byte[] prev, int count, int bpp)`
`private void`	`decodeIdat()`
`private static void`	`decodePaethFilter(byte[] curr, byte[] prev, int count, int bpp)`
`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)`
`private PdfObject`	`getColorspace()`
`private Image`	`getImage()`
`static Image`	`getImage(byte[] data)`	Reads a PNG from a byte array.
`private static Image`	`getImage(java.io.InputStream is)`	Reads a PNG from a stream.
`static Image`	`getImage(java.net.URL url)`	Reads a PNG from an url.
`private static int`	`getInt(java.io.InputStream is)`	Gets an `int` from an `InputStream`.
`private int[]`	`getPixel(byte[] curr)`
`private static java.lang.String`	`getString(java.io.InputStream is)`	Gets a `String` from an `InputStream`.
`private static int`	`getWord(java.io.InputStream is)`	Gets a `word` from an `InputStream`.
`private static int`	`paethPredictor(int a, int b, int c)`
`private void`	`processPixels(byte[] curr, int xOffset, int step, int y, int width)`
`private void`	`readPng()`
`private static void`	`setPixel(byte[] image, int[] data, int offset, int size, int x, int y, int bitDepth, int bytesPerRow)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

PNGID
```
public static final int[] PNGID
```
Some PNG specific values.

IHDR
```
private static final java.lang.String IHDR
```
A PNG marker.

See Also:

Constant Field Values

PLTE
```
private static final java.lang.String PLTE
```
A PNG marker.

See Also:

Constant Field Values

IDAT
```
private static final java.lang.String IDAT
```
A PNG marker.

See Also:

Constant Field Values

IEND
```
private static final java.lang.String IEND
```
A PNG marker.

See Also:

Constant Field Values

tRNS
```
private static final java.lang.String tRNS
```
A PNG marker.

See Also:

Constant Field Values

pHYs
```
private static final java.lang.String pHYs
```
A PNG marker.

See Also:

Constant Field Values

gAMA
```
private static final java.lang.String gAMA
```
A PNG marker.

See Also:

Constant Field Values

cHRM
```
private static final java.lang.String cHRM
```
A PNG marker.

See Also:

Constant Field Values

sRGB
```
private static final java.lang.String sRGB
```
A PNG marker.

See Also:

Constant Field Values

iCCP
```
private static final java.lang.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
```
private final java.io.InputStream is
```

dataStream

private java.io.DataInputStream dataStream

width
```
private int width
```

height
```
private int height
```

bitDepth
```
private int bitDepth
```

colorType
```
private int colorType
```

compressionMethod
```
private int compressionMethod
```

filterMethod
```
private int filterMethod
```

interlaceMethod
```
private int interlaceMethod
```

additional
```
private final PdfDictionary additional
```

image
```
private byte[] image
```

smask
```
private byte[] smask
```

trans
```
private byte[] trans
```

idat

private final PngImage.NewByteArrayOutputStream idat

dpiX
```
private int dpiX
```

dpiY
```
private int dpiY
```

XYRatio
```
private float XYRatio
```

genBWMask
```
private boolean genBWMask
```

palShades
```
private boolean palShades
```

transRedGray
```
private int transRedGray
```

transGreen
```
private int transGreen
```

transBlue
```
private int transBlue
```

inputBands
```
private int inputBands
```

bytesPerPixel
```
private int bytesPerPixel
```

colorTable
```
private byte[] colorTable
```

gamma
```
private float gamma
```

hasCHRM
```
private boolean hasCHRM
```

xW
```
private float xW
```

yW
```
private float yW
```

xR
```
private float xR
```

yR
```
private float yR
```

xG
```
private float xG
```

yG
```
private float yG
```

xB
```
private float xB
```

yB
```
private float yB
```

intent
```
private PdfName intent
```

icc_profile

private java.awt.color.ICC_Profile icc_profile

Constructor Detail
- PngImage
```
private PngImage(java.io.InputStream is)
```
  Creates a new instance of PngImage

Method Detail

getImage
```
public static Image getImage(java.net.URL url)
                      throws java.io.IOException
```
Reads a PNG from an url.

Parameters:

url - the url

Returns:

the image

Throws:

java.io.IOException - on error

getImage

private static Image getImage(java.io.InputStream is)
                       throws java.io.IOException

Reads a PNG from a stream.

Parameters:: is - the stream
Returns:: the image
Throws:: java.io.IOException - on error

getImage
```
public static Image getImage(byte[] data)
                      throws java.io.IOException
```
Reads a PNG from a byte array.

Parameters:

data - the byte array

Returns:

the image

Throws:

java.io.IOException - on error

checkMarker

private boolean checkMarker(java.lang.String s)

readPng

private void readPng()
              throws java.io.IOException

Throws:: java.io.IOException

getColorspace
```
private PdfObject getColorspace()
```

getImage

private Image getImage()
                throws java.io.IOException

Throws:: java.io.IOException

decodeIdat
```
private void decodeIdat()
```

decodePass

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

processPixels

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

setPixel

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

getPixel

private int[] getPixel(byte[] curr)

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
```
private static final int getInt(java.io.InputStream is)
                         throws java.io.IOException
```
Gets an int from an InputStream.

Parameters:

is - an InputStream

Returns:

the value of an int

Throws:

java.io.IOException

getWord
```
private static final int getWord(java.io.InputStream is)
                          throws java.io.IOException
```
Gets a word from an InputStream.

Parameters:

is - an InputStream

Returns:

the value of an int

Throws:

java.io.IOException

getString

private static final java.lang.String getString(java.io.InputStream is)
                                         throws java.io.IOException

Gets a String from an InputStream.

Parameters:: is - an InputStream
Returns:: the value of an int
Throws:: java.io.IOException

Class PngImage

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

PNGID

IHDR

PLTE

IDAT

IEND

tRNS

pHYs

gAMA

cHRM

sRGB

iCCP

TRANSFERSIZE

PNG_FILTER_NONE

PNG_FILTER_SUB

PNG_FILTER_UP

PNG_FILTER_AVERAGE

PNG_FILTER_PAETH

intents

is

dataStream

width

height

bitDepth

colorType

compressionMethod

filterMethod

interlaceMethod

additional

image

smask

trans

idat

dpiX

dpiY

XYRatio

genBWMask

palShades

transRedGray

transGreen

transBlue

inputBands

bytesPerPixel

colorTable

gamma

hasCHRM

xW

yW

xR

yR

xG

yG

xB

yB

intent

icc_profile

Constructor Detail

PngImage

Method Detail

getImage

getImage

getImage

checkMarker

readPng

getColorspace

getImage

decodeIdat

decodePass

processPixels

setPixel

getPixel

decodeSubFilter

decodeUpFilter

decodeAverageFilter