org.hippoecm.frontend.plugins.gallery.imageutil

Class ImageUtils

java.lang.Object

org.hippoecm.frontend.plugins.gallery.imageutil.ImageUtils

public class ImageUtils
extends Object

Generic image manipulation utility methods.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ImageUtils.ScalingStrategy The available strategies for scaling images.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ImageUtils() Prevent instantiation

Method Summary

Modifier and Type	Method and Description
static InputStream	convertToRGB(InputStream is, ColorModel colorModel) Converts image raster data to a JPEG with RGB color space.
static InputStream	convertToRGB(InputStream is, ImageMetaData.ColorModel colorModel) Deprecated. This method is deprecated in favor of convertToRGB(InputStream is, ColorModel colorModel)
static String	fixMimeType(String mimeType) Deprecated. Use MimeTypeHelper.sanitizeMimeType instead
static ImageReader	getImageReader(String aMimeType) Returns an image reader for a MIME type.
static ImageWriter	getImageWriter(String aMimeType) Returns an image writer for a MIME type.
static BufferedImage	scaleImage(BufferedImage img, int targetWidth, int targetHeight, ImageUtils.ScalingStrategy strategy) Returns a scaled instance of the provided BufferedImage.
static BufferedImage	scaleImage(BufferedImage img, int xOffset, int yOffset, int sourceWidth, int sourceHeight, int targetWidth, int targetHeight, Object hint, boolean highQuality)
static BufferedImage	scaleImage(BufferedImage img, int targetWidth, int targetHeight, Object hint, boolean highQuality) Deprecated. Use scaleImage(java.awt.image.BufferedImage, int, int, org.hippoecm.frontend.plugins.gallery.imageutil.ImageUtils.ScalingStrategy) instead for faster scaling and/or better image quality)}
static ByteArrayOutputStream	writeImage(ImageWriter writer, BufferedImage image) Returns the data of a BufferedImage as a binary output stream.
static ByteArrayOutputStream	writeImage(ImageWriter writer, BufferedImage image, float compressionQuality) Returns the data of a BufferedImage as a binary output stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

ImageUtils

protected ImageUtils()

Prevent instantiation

Method Detail

fixMimeType

@Deprecated
public static String fixMimeType(String mimeType)

Deprecated. Use MimeTypeHelper.sanitizeMimeType instead

Fixes issues for certain image MIME types.

Parameters:

mimeType - the MIME type to fix

Returns:

the fixed MIME type

getImageReader

public static ImageReader getImageReader(String aMimeType)

Returns an image reader for a MIME type.

Parameters:

aMimeType - MIME type

Returns:

an image reader for the given MIME type, or null if no image reader could be created for the given MIME type.

getImageWriter

public static ImageWriter getImageWriter(String aMimeType)

Returns an image writer for a MIME type.

Parameters:

aMimeType - MIME type

Returns:

an image writer for the given MIME type, or null if no image writer could be created for the given MIME type.

writeImage

public static ByteArrayOutputStream writeImage(ImageWriter writer,
                                               BufferedImage image,
                                               float compressionQuality)
                                        throws IOException

Returns the data of a BufferedImage as a binary output stream. If the image is null, a stream of zero bytes is returned.

Parameters:

writer - the writer to use for writing the image data.

image - the image to write.

compressionQuality - a float between 0 and 1 that indicates the desired compression quality. Values lower than 0 will be interpreted as 0, values higher than 1 will be interpreted as 1.

Returns:

an output stream with the data of the given image.

Throws:

IOException - when creating the binary output stream failed.

writeImage

public static ByteArrayOutputStream writeImage(ImageWriter writer,
                                               BufferedImage image)
                                        throws IOException

Returns the data of a BufferedImage as a binary output stream. If the image is null, a stream of zero bytes is returned. The data is written with a compression quality of 1.

Parameters:

writer - the writer to use for writing the image data.

image - the image to write.

Returns:

an output stream with the data of the given image.

Throws:

IOException - when creating the binary output stream failed.

scaleImage

public static BufferedImage scaleImage(BufferedImage img,
                                       int targetWidth,
                                       int targetHeight,
                                       ImageUtils.ScalingStrategy strategy)

Returns a scaled instance of the provided BufferedImage.

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

strategy - the strategy to use for scaling the image

Returns:

a scaled version of the original BufferedImage, or null if either the target width or target height is 0 or less.

scaleImage

@Deprecated
public static BufferedImage scaleImage(BufferedImage img,
                                                   int targetWidth,
                                                   int targetHeight,
                                                   Object hint,
                                                   boolean highQuality)

Deprecated. Use scaleImage(java.awt.image.BufferedImage, int, int, org.hippoecm.frontend.plugins.gallery.imageutil.ImageUtils.ScalingStrategy) instead for faster scaling and/or better image quality)}

Returns a scaled instance of the provided BufferedImage.

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)

highQuality - 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, or null if either the target width or target height is 0 or less.

scaleImage

public static BufferedImage scaleImage(BufferedImage img,
                                       int xOffset,
                                       int yOffset,
                                       int sourceWidth,
                                       int sourceHeight,
                                       int targetWidth,
                                       int targetHeight,
                                       Object hint,
                                       boolean highQuality)

convertToRGB

public static InputStream convertToRGB(InputStream is,
                                       ColorModel colorModel)
                                throws IOException,
                                       UnsupportedImageException

Converts image raster data to a JPEG with RGB color space. Only images with color space CMYK and YCCK are converted, other images are left untouched. Rationale: Java's ImageIO can't process 4-component images and Java2D can't apply AffineTransformOp either, so we have to convert raster data to a JPG with RGB color space. The technique used in this method is due to Mark Stephens, and free for any use. See http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4799903 or http://www.mail-archive.com/java2d-interest@capra.eng.sun.com/msg03247.html

Parameters:

is - the image data

colorModel - the color model of the image

Returns:

the RGB version of the supplied image

Throws:

IOException

UnsupportedImageException

convertToRGB

@Deprecated
public static InputStream convertToRGB(InputStream is,
                                                   ImageMetaData.ColorModel colorModel)
                                            throws IOException,
                                                   UnsupportedImageException

Deprecated. This method is deprecated in favor of convertToRGB(InputStream is, ColorModel colorModel)

Convert image in CYYK or CMYK color space to RGB using convertToRGB(InputStream is, ColorModel colorModel)

Parameters:

is - the image data

colorModel - the color model of the image

Returns:

the RGB version of the supplied image

Throws:

IOException

UnsupportedImageException