org.knime.core.data.image.png
Class PNGImageContent

java.lang.Object
  org.knime.core.data.image.png.PNGImageContent

All Implemented Interfaces:

ImageContent

public class PNGImageContent
extends Object
implements ImageContent

Content of a PNG image. It only wraps a byte[] which is supposed to be PNG content. The rendering methods will delegate all work to BufferedImage.

Author:

Thomas Gabriel, KNIME.com, Zurich, Switzerland

Field Summary

static DataType

TYPE Type for PNG cells.

Constructor Summary

PNGImageContent()
Framework constructor for restoring content.

PNGImageContent(byte[] imageBytes)
Creates PNG image content from byte array.

PNGImageContent(InputStream is)
Reads image content from a stream.

Method Summary

(package private) static PNGImageContent	deserialize(DataCellDataInput input) Deserialize method for DataCell implementation.
byte[]	getByteArray() Get a copy of the underlying byte array.
byte[]	getByteArrayReference() Get a reference to the underlying byte array.
Image	getImage() Get the image represented by this object.
Dimension	getPreferredSize() Preferred dimension, width and height, for the given image to be rendered.
String	getSummary()
void	paint(Graphics2D g, int width, int height) Render image into argument graphics object.
void	save(OutputStream output) Save the image content to an output stream.
void	serialize(DataCellDataOutput output) Serialize method for image content.
DataCell	toImageCell() Factory method to generate cell implementation.

Methods inherited from class java.lang.Object

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

Field Detail

TYPE

public static final DataType TYPE

Type for PNG cells.

Constructor Detail

PNGImageContent

public PNGImageContent()

Framework constructor for restoring content. Do not use!

PNGImageContent

public PNGImageContent(byte[] imageBytes)

Creates PNG image content from byte array.

Parameters:

imageBytes - The image bytes.

Throws:

NullPointerException - If the argument is null.

IllegalArgumentException - If the argument does not represent a valid png byte stream (according to ImageIO.read(InputStream).

PNGImageContent

public PNGImageContent(InputStream is)
                throws IOException

Reads image content from a stream. The reader will read content until the end of the stream, it will not close the stream.

Parameters:

is - The input stream.

Throws:

IOException - If reading from the stream fails.

NullPointerException - If the argument is null;

IllegalArgumentException - If the argument does not represent a valid png byte stream (according to ImageIO.read(InputStream).

Method Detail

getByteArrayReference

public byte[] getByteArrayReference()

Get a reference to the underlying byte array. The caller must not modify the returned array but should use the getByteArray() if necessary.

Returns:

Reference to the underlying byte array.

getByteArray

public byte[] getByteArray()

Get a copy of the underlying byte array.

Returns:

A new copy.

See Also:

getByteArrayReference()

getImage

public Image getImage()

Get the image represented by this object.

Returns:

The image.

Throws:

IllegalStateException - If the image can't be read from the internal memory representation (the Image is not actually stored as part of this cell but kept in a SoftReference)

paint

public void paint(Graphics2D g,
                  int width,
                  int height)

Render image into argument graphics object. The aspect ration of the image must be retained, i.e. the width and height are maximum values that do not need to be fulfilled both at the same time.

Specified by:

paint in interface ImageContent

Parameters:

g - To paint to.

width - image maximum width

height - image maximum height

save

public void save(OutputStream output)
          throws IOException

Save the image content to an output stream.

Specified by:

save in interface ImageContent

Parameters:

output - To save to.

Throws:

IOException - If that fails.

deserialize

static PNGImageContent deserialize(DataCellDataInput input)
                            throws IOException

Deserialize method for DataCell implementation.

Parameters:

input - To read from.

Returns:

A new image content.

Throws:

IOException - If that fails.

serialize

public void serialize(DataCellDataOutput output)
               throws IOException

Serialize method for image content.

Parameters:

output - To save to.

Throws:

IOException - If that fails for any reason.

toImageCell

public DataCell toImageCell()

Factory method to generate cell implementation.

Specified by:

toImageCell in interface ImageContent

Returns:

A (likely new) cell representing this image.

getPreferredSize

public Dimension getPreferredSize()

Preferred dimension, width and height, for the given image to be rendered.

Specified by:

getPreferredSize in interface ImageContent

Returns:

preferred dimension

getSummary

public String getSummary()

Specified by:

getSummary in interface ImageContent

Returns:

short summary representing this image content object.