com.jalios.io
Class ImageUtil

java.lang.Object
  com.jalios.io.ImageUtil

public class ImageUtil
extends Object

Utility class to manipulate image.

Since:

jcms-5.5.0

Version:

$Revision: 29654 $

Author:

Olivier Jaquemet

Field Summary

static String

REVISION

Constructor Summary

ImageUtil()

Method Summary

static File	createGIFThumbnail(File imageFile, int maxWidth, int maxHeight) Creates a thumbnail of the given file image in a temporary location in the GIF format, return the corresponding File.
static File	createJPEGThumbnail(File imageFile, int maxWidth, int maxHeight) Creates a thumbnail of the given file image in a temporary location in the JPEG format, return the corresponding File.
static File	createThumbnail(File imageFile, ImageFormat format, int maxWidth, int maxHeight)
static File	createThumbnail(File imageFile, ImageFormat format, int maxWidth, int maxHeight, String background) Creates a thumbnail of the given file image in a temporary location in the given format, return the corresponding File.
static File	crop(File imageFile, ImageFormat format, int x1, int y1, int x2, int y2, String background)
static BufferedImage	cropImage(BufferedImage image, int x1, int y1, int x2, int y2, String background)
static BufferedImage	getScaledInstance(BufferedImage img, int targetWidth, int targetHeight, Object hint, boolean higherQuality) Convenience method that returns a scaled instance of the provided BufferedImage.
static String[]	getSupportedReadFormat()
static String[]	getSupportedWriteFormat()
static boolean	isImage(File file) Detects if the given file is an image file, using its extension.
static BufferedImage	readImage(File file) Read the given image file and return the BufferedImage
static BufferedImage	resizeImage(BufferedImage image, int maxWidth, int maxHeight, boolean doNotEnlarge, String background) Resizes the given BufferedImage to a new BufferedImage file with the given sizes.
static File	rotate(File imageFile, ImageFormat format, int angle, String background)
static BufferedImage	rotateImage(BufferedImage image, int angle, String background)
static void	setQualityRenderingHints(Graphics2D g2d)
static File	writeGIF(BufferedImage image, File outFile) Write the given BufferedImage to the given outfile in GIF format.
static File	writeJPEG(BufferedImage image, File outFile) Write the given BufferedImage to the given outfile in JPEG format.

Methods inherited from class java.lang.Object

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

Field Detail

REVISION

public static final String REVISION

See Also:

Constant Field Values

Constructor Detail

ImageUtil

public ImageUtil()

Method Detail

isImage

public static boolean isImage(File file)

Detects if the given file is an image file, using its extension.
Use those possibles extension:

"jpg"

"jpeg"

"gif"

"png"

Parameters:

file - the file to check

Returns:

true if the given file is an image, false otherwise.

createGIFThumbnail

public static File createGIFThumbnail(File imageFile,
                                      int maxWidth,
                                      int maxHeight)

Creates a thumbnail of the given file image in a temporary location in the GIF format, return the corresponding File.

Parameters:

imageFile - the image file of which to make a thumbnail.

maxWidth - the maximum width of the output image

maxHeight - the maximum height of the output image

Returns:

the thumbnail File or null if it could not be created.

See Also:

createThumbnail(File, ImageFormat, int, int)

createJPEGThumbnail

public static File createJPEGThumbnail(File imageFile,
                                       int maxWidth,
                                       int maxHeight)

Creates a thumbnail of the given file image in a temporary location in the JPEG format, return the corresponding File.

Parameters:

imageFile - the image file of which to make a thumbnail.

maxWidth - the maximum width of the output image

maxHeight - the maximum height of the output image

Returns:

the thumbnail File or null if it could not be created.

See Also:

createThumbnail(File, ImageFormat, int, int)

createThumbnail

public static File createThumbnail(File imageFile,
                                   ImageFormat format,
                                   int maxWidth,
                                   int maxHeight)

See Also:

createThumbnail(File, ImageFormat, int, int, String)

createThumbnail

public static File createThumbnail(File imageFile,
                                   ImageFormat format,
                                   int maxWidth,
                                   int maxHeight,
                                   String background)

Creates a thumbnail of the given file image in a temporary location in the given format, return the corresponding File.

Parameters:

imageFile - the image file of which to make a thumbnail.

format - the image format to use, ImageFormat.GIF, ImageFormat.JPEG, if null the ImageFormat.JPEG format is used

maxWidth - the maximum width of the output image

maxHeight - the maximum height of the output image

background - the background color (eg "FFFFFF") if sets the image dimension will be set maxWidth and maxHeight

Returns:

the thumbnail File or null if it could not be created.

readImage

public static BufferedImage readImage(File file)

Read the given image file and return the BufferedImage

Parameters:

file - the image file to read

Returns:

a new BufferedImage or null if the file could not be read.

Throws:

IllegalArgumentException - if file is null.

setQualityRenderingHints

public static void setQualityRenderingHints(Graphics2D g2d)

getScaledInstance

public static BufferedImage getScaledInstance(BufferedImage img,
                                              int targetWidth,
                                              int targetHeight,
                                              Object hint,
                                              boolean higherQuality)

Convenience method that returns a scaled instance of the provided BufferedImage. http://today.java.net/pub/a/today/2007/04/03/perils-of-image-getscaledinstance.html

Parameters:

img - the original image to be scaled

targetWidth - the desired width of the scaled instance, in pixels

targetHeight - the desired height of the scaled instance, in pixels

hint - one of the rendering hints that corresponds to RenderingHints.KEY_INTERPOLATION (e.g. RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR, RenderingHints.VALUE_INTERPOLATION_BILINEAR, RenderingHints.VALUE_INTERPOLATION_BICUBIC)

higherQuality - if true, this method will use a multi-step scaling technique that provides higher quality than the usual one-step technique (only useful in downscaling cases, where targetWidth or targetHeight is smaller than the original dimensions, and generally only when the BILINEAR hint is specified)

Returns:

a scaled version of the original BufferedImage

rotate

public static File rotate(File imageFile,
                          ImageFormat format,
                          int angle,
                          String background)

rotateImage

public static BufferedImage rotateImage(BufferedImage image,
                                        int angle,
                                        String background)

crop

public static File crop(File imageFile,
                        ImageFormat format,
                        int x1,
                        int y1,
                        int x2,
                        int y2,
                        String background)

cropImage

public static BufferedImage cropImage(BufferedImage image,
                                      int x1,
                                      int y1,
                                      int x2,
                                      int y2,
                                      String background)

resizeImage

public static BufferedImage resizeImage(BufferedImage image,
                                        int maxWidth,
                                        int maxHeight,
                                        boolean doNotEnlarge,
                                        String background)

Resizes the given BufferedImage to a new BufferedImage file with the given sizes.

Parameters:

image - the image to resize.

maxWidth - the maximum width of the output image

maxHeight - the maximum height of the output image

doNotEnlarge - do not increase image size if image is smaller than given maximum dimension.

background - the background color (eg "FFFFFF") if sets the image dimension will be set maxWidth and maxHeight

Returns:

the resized BufferedImage

Throws:

IllegalArgumentException - if image is null.

writeJPEG

public static File writeJPEG(BufferedImage image,
                             File outFile)

Write the given BufferedImage to the given outfile in JPEG format.
Delete the given file if it already exists.

Parameters:

image - the BufferedImage to write to a file.

outFile - the file in which to write the image

Returns:

the given File or null if the image could not be written.

Throws:

IllegalArgumentException - if image or outFile is null.

writeGIF

public static File writeGIF(BufferedImage image,
                            File outFile)

Write the given BufferedImage to the given outfile in GIF format.
Delete the given file if it already exists.

Parameters:

image - the BufferedImage to write to a file.

outFile - the file in which to write the image

Returns:

the given File or null if the image could not be written.

Throws:

IllegalArgumentException - if image or outFile is null.

getSupportedReadFormat

public static String[] getSupportedReadFormat()

Returns:

an array of image format that can be read.

See Also:

ImageIO.getReaderFormatNames()

getSupportedWriteFormat

public static String[] getSupportedWriteFormat()

Returns:

an array of image format that can be written.

See Also:

ImageIO.getWriterFormatNames()