ilog.views.util

Class IlvImageUtil

java.lang.Object

ilog.views.util.IlvImageUtil

public class IlvImageUtil
extends Object

This class defines a set of utility methods to load and create images.

Since:

JViews 5.5

Method Summary

Modifier and Type	Method and Description
static BufferedImage	createBufferedImage(Image image, int imageType) Creates a BufferedImage of the specified type from the given image.
static Image	getImageFromFile(Class<?> loader, String file) This is a utility method that creates an image from a file stored in a JAR file.
static Dimension	getImageSize(Image image) Returns the size (dimensions) of an image.
static Image	getScaledImage(Image orig, int scaledWidth, int scaledHeight, boolean preserveAlpha, int hints) Creates a scaled image.
static Image	loadImage(byte[] imagedata) Loads an image from the specified byte array.
static Image	loadImage(String fileName) Loads an image from the specified file.
static BufferedImage	loadImage(String fileName, int imageType) Loads an image from the specified file as a BufferedImage of the specified type.
static Image	loadImage(URL url) Loads an image from the specified URL.
static BufferedImage	loadImage(URL url, int imageType) Loads an image from the specified URL as a BufferedImage of the specified type.
static Image	loadImageFromFile(Class<?> loader, String filename) Utility method that loads an image from a file stored in a JAR file.
static void	writeJPEGImage(BufferedImage image, File filename) Writes an image to the specified file, in JPEG format.
static void	writeJPEGImage(BufferedImage image, float quality, File filename) Writes an image to the specified file, in JPEG format, with given quality.
static void	writeJPEGImage(BufferedImage image, float quality, OutputStream output) Writes an image to the specified file, in JPEG format, with given quality.
static void	writeJPEGImage(BufferedImage image, OutputStream output) Writes an image to the specified file, in JPEG format.
static void	writePNGImage(BufferedImage image, Color transparentColor, File filename) Writes an image to the specified file, in PNG format, with given transparent color.
static void	writePNGImage(BufferedImage image, Color transparentColor, OutputStream output) Writes an image to the specified file, in PNG format, with given transparent color.
static void	writePNGImage(BufferedImage image, File filename) Writes an image to the specified file, in PNG format.
static void	writePNGImage(BufferedImage image, OutputStream output) Writes an image to the specified file, in PNG format.

Methods inherited from class java.lang.Object

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

Method Detail

getImageFromFile

public static Image getImageFromFile(Class<?> loader,
                                     String file)
                              throws IOException

This is a utility method that creates an image from a file stored in a JAR file. To read the image file, the method uses the InputStream returned by the method getResourceAsStream called on the loader object.

Parameters:

loader - The Class object on which the method getResourceAsStream is called.

file - The location of the file that contains the image to be read. The location must be specified according to the location of the loader class. For details, see the documentation of Class.getResourceAsStream.

Returns:

The created image.

Throws:

IOException - An exception occurred while trying to read the bytes defining the image.

loadImageFromFile

public static Image loadImageFromFile(Class<?> loader,
                                      String filename)
                               throws IOException

Utility method that loads an image from a file stored in a JAR file. The method returns once the image is fully loaded.

Parameters:

loader - The Class object on which the method getResourceAsStream is called.

filename - The location of the file that contains the image to be read. The location must be specified according to the location of the loader class.

Returns:

The loaded image, or null if the loading failed.

Throws:

IOException - An exception occurred while trying to read the bytes defining the image.

See Also:

getImageFromFile(java.lang.Class<?>, java.lang.String)

loadImage

public static Image loadImage(URL url)

Loads an image from the specified URL.

Parameters:

url - The URL of the image.

Returns:

The image, or null if the loading failed.

loadImage

public static Image loadImage(String fileName)

Loads an image from the specified file.

Parameters:

fileName - The image file name.

Returns:

The image, or null if the loading failed.

loadImage

public static Image loadImage(byte[] imagedata)

Loads an image from the specified byte array.

Parameters:

imagedata - An array of bytes, representing the image.

Returns:

The image, or null if the loading failed.

Since:

JViews 8.7

getImageSize

public static Dimension getImageSize(Image image)

Returns the size (dimensions) of an image.

Parameters:

image - The image.

Returns:

Its size, in pixels, or null if the image is invalid.

Since:

JViews 8.9

createBufferedImage

public static BufferedImage createBufferedImage(Image image,
                                                int imageType)

Creates a BufferedImage of the specified type from the given image.

Parameters:

image - The original image.

imageType - The type of the image to create. It can be any of the predefined image types defined in the java.awt.image.BufferedImage class.

loadImage

public static BufferedImage loadImage(String fileName,
                                      int imageType)

Loads an image from the specified file as a BufferedImage of the specified type.

Note: This method can be about 10 times slower than loadImage(String). Use it only if you need the result to be a BufferedImage.

Parameters:

fileName - The image file name.

imageType - The type of the image to create. It can be any of the predefined image types defined in the java.awt.image.BufferedImage class.

Returns:

The image, or null if the loading failed.

loadImage

public static BufferedImage loadImage(URL url,
                                      int imageType)

Loads an image from the specified URL as a BufferedImage of the specified type.

Note: This method can be about 10 times slower than loadImage(URL) . Use it only if you need the result to be a BufferedImage.

Parameters:

url - The URL of the image.

imageType - The type of the image to create. It can be any of the predefined image types defined in the java.awt.image.BufferedImage class.

Returns:

The image, or null if the loading failed.

writeJPEGImage

public static void writeJPEGImage(BufferedImage image,
                                  File filename)
                           throws IOException

Writes an image to the specified file, in JPEG format.

Parameters:

image - The contents of the image.

filename - Name of the file where it should be stored.

Throws:

IOException

Since:

JViews 8.9

writeJPEGImage

public static void writeJPEGImage(BufferedImage image,
                                  OutputStream output)
                           throws IOException

Writes an image to the specified file, in JPEG format.

Parameters:

image - The contents of the image.

output - The output destination.

Throws:

IOException

Since:

JViews 8.9

writeJPEGImage

public static void writeJPEGImage(BufferedImage image,
                                  float quality,
                                  File filename)
                           throws IOException

Writes an image to the specified file, in JPEG format, with given quality.

Parameters:

image - The contents of the image.

quality - The quality, influences the JPEG compression factor. A value between 0.0 and 1.0. 1.0 is the optimal quality, with no compression.

filename - Name of the file where it should be stored.

Throws:

IOException

Since:

JViews 8.9

writeJPEGImage

public static void writeJPEGImage(BufferedImage image,
                                  float quality,
                                  OutputStream output)
                           throws IOException

Writes an image to the specified file, in JPEG format, with given quality.

Parameters:

image - The contents of the image.

quality - The quality, influences the JPEG compression factor. A value between 0.0 and 1.0. 1.0 is the optimal quality, with no compression.

output - The output destination.

Throws:

IOException

Since:

JViews 8.9

writePNGImage

public static void writePNGImage(BufferedImage image,
                                 File filename)
                          throws IOException

Writes an image to the specified file, in PNG format.

Parameters:

image - The contents of the image.

filename - Name of the file where it should be stored.

Throws:

IOException

Since:

JViews 8.9

writePNGImage

public static void writePNGImage(BufferedImage image,
                                 OutputStream output)
                          throws IOException

Writes an image to the specified file, in PNG format.

Parameters:

image - The contents of the image.

output - The output destination.

Throws:

IOException

Since:

JViews 8.9

writePNGImage

public static void writePNGImage(BufferedImage image,
                                 Color transparentColor,
                                 File filename)
                          throws IOException

Writes an image to the specified file, in PNG format, with given transparent color.

Parameters:

image - The contents of the image.

transparentColor - The color to mark as transparent.

filename - Name of the file where it should be stored.

Throws:

IOException

Since:

JViews 8.9

writePNGImage

public static void writePNGImage(BufferedImage image,
                                 Color transparentColor,
                                 OutputStream output)
                          throws IOException

Writes an image to the specified file, in PNG format, with given transparent color.

Parameters:

image - The contents of the image.

transparentColor - The color to mark as transparent.

output - The output destination.

Throws:

IOException

Since:

JViews 8.9

getScaledImage

public static Image getScaledImage(Image orig,
                                   int scaledWidth,
                                   int scaledHeight,
                                   boolean preserveAlpha,
                                   int hints)

Creates a scaled image.

Parameters:

orig - The original image.

scaledWidth - The scaled width

scaledHeight - The scaled height

preserveAlpha - Whether the alpha channel must be preserved.

hints - The flags to indicate the type of algorithm to use for image resampling (Image.SCALE_FAST, ...).

Since:

JViews 8.7

See Also:

Image.SCALE_DEFAULT, Image.SCALE_FAST, Image.SCALE_SMOOTH, Image.SCALE_REPLICATE, Image.SCALE_AREA_AVERAGING