org.ametys.core.util

Class ImageHelper

java.lang.Object

org.ametys.core.util.ImageHelper

public final class ImageHelper
extends Object

Helper for manipulating images.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	ImageHelper()

Method Summary

Modifier and Type	Method and Description
protected static BufferedImage	_cropImage(BufferedImage src, int x, int y, int height, int width) Crop the image by a specified rectangular region.
protected static BufferedImage	_resizeImage(BufferedImage src, int height, int width, int maxHeight, int maxWidth) Resize the buffered image
static BufferedImage	generateCroppedImage(BufferedImage src, int x, int y, int height, int width) Crop the image by a specified rectangular region.
static void	generateCroppedImage(InputStream is, OutputStream os, String format, int x, int y, int height, int width) Crop an image from a source InputStream.
static BufferedImage	generateThumbnail(BufferedImage src, int height, int width, int maxHeight, int maxWidth) Generates a BufferedImage with specified size instructions, scaling if necessary.
static void	generateThumbnail(InputStream is, OutputStream os, String format, int height, int width, int maxHeight, int maxWidth) Generates a thumbnail from a source InputStream.
static BufferedImage	read(InputStream is) Returns a BufferedImage as from the supplied input stream

Methods inherited from class java.lang.Object

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

Constructor Detail

ImageHelper

private ImageHelper()

Method Detail

read

public static BufferedImage read(InputStream is)
                          throws IOException

Returns a BufferedImage as from the supplied input stream

Parameters:

is - The input stream

Returns:

The buffered image

Throws:

IOException - if an error occurs during reading.

generateThumbnail

public static void generateThumbnail(InputStream is,
                                     OutputStream os,
                                     String format,
                                     int height,
                                     int width,
                                     int maxHeight,
                                     int maxWidth)
                              throws IOException

Generates a thumbnail from a source InputStream. Note that if final width and height are equals to source width and height, the stream is just copied.

Parameters:

is - the source.

os - the destination.

format - the image format. Must be one of "gif", "png" or "jpg".

height - the specified height. Ignored if negative.

width - the specified width. Ignored if negative.

maxHeight - the maximum image height. Ignored if height or width is specified.

maxWidth - the maximum image width. Ignored if height or width is specified.

Throws:

IOException - if an error occurs when manipulating streams.

generateThumbnail

public static BufferedImage generateThumbnail(BufferedImage src,
                                              int height,
                                              int width,
                                              int maxHeight,
                                              int maxWidth)
                                       throws IOException

Generates a BufferedImage with specified size instructions, scaling if necessary.

Parameters:

src - the source image.

height - the specified height. Ignored if negative.

width - the specified width. Ignored if negative.

maxHeight - the maximum image height. Ignored if height or width is specified.

maxWidth - the maximum image width. Ignored if height or width is specified.

Returns:

a scaled BufferedImage. If no size modification is required, this will return the src image.

Throws:

IOException - If the source image is not readable

generateCroppedImage

public static void generateCroppedImage(InputStream is,
                                        OutputStream os,
                                        String format,
                                        int x,
                                        int y,
                                        int height,
                                        int width)
                                 throws IOException

Crop an image from a source InputStream. Note that if any of the coordinate and size are negatives, the image will just be copied.

Parameters:

is - the source.

os - the destination.

format - the image format. Must be one of "gif", "png" or "jpg".

x - The X coordinate of the upper-left corner of the specified rectangular region

y - the Y coordinate of the upper-left corner of the specified rectangular region

height - the width of the specified rectangular region

width - the height of the specified rectangular region

Throws:

IOException - If an error occurs

generateCroppedImage

public static BufferedImage generateCroppedImage(BufferedImage src,
                                                 int x,
                                                 int y,
                                                 int height,
                                                 int width)
                                          throws IOException

Crop the image by a specified rectangular region. The returned BufferedImage shares the same data array as the original image.

Parameters:

src - the source image.

x - The X coordinate of the upper-left corner of the specified rectangular region

y - the Y coordinate of the upper-left corner of the specified rectangular region

height - the width of the specified rectangular region

width - the height of the specified rectangular region

Returns:

a scaled BufferedImage. If no size modification is required, this will return the src image.

Throws:

IOException - If the source image is not readable

_cropImage

protected static BufferedImage _cropImage(BufferedImage src,
                                          int x,
                                          int y,
                                          int height,
                                          int width)
                                   throws IOException

Crop the image by a specified rectangular region. The returned BufferedImage shares the same data array as the original image.

Parameters:

src - the source image.

x - The X coordinate of the upper-left corner of the specified rectangular region

y - the Y coordinate of the upper-left corner of the specified rectangular region

height - the width of the specified rectangular region

width - the height of the specified rectangular region

Returns:

a scaled BufferedImage. If no size modification is required, this will return the src image.

Throws:

IOException - If the source image is not readable

_resizeImage

protected static BufferedImage _resizeImage(BufferedImage src,
                                            int height,
                                            int width,
                                            int maxHeight,
                                            int maxWidth)
                                     throws IOException

Resize the buffered image

Parameters:

src - the source image

height - the specified height. Ignored if negative.

width - the specified width. Ignored if negative.

maxHeight - the maximum image height. Ignored if height or width is specified.

maxWidth - the maximum image width. Ignored if height or width is specified.

Returns:

a scaled BufferedImage. If no size modification is required, this will return the src image.

Throws:

IOException - If the source image is not readable