Package org.ametys.core.util

Class ImageHelper

java.lang.Object

org.ametys.core.util.ImageHelper

public final class ImageHelper
extends Object

Helper for manipulating images.

Field Summary

Fields

Modifier and Type	Field	Description
private static float	IMAGE_QUALITY

Constructor Summary

Constructors

Modifier	Constructor	Description
private	ImageHelper()

Method Summary

Modifier and Type	Method	Description
protected static BufferedImage	_cropImage(BufferedImage src, int height, int width)	Crop the image to the size specified to the center of the image.
protected static BufferedImage	_cropImage(BufferedImage src, int x, int y, int height, int width)	Crop the image by a specified rectangular region.
private static boolean	_isJpeg(String format)
private static boolean	_needsChanges(int height, int width, int maxHeight, int maxWidth, int cropHeight, int cropWidth)
protected static BufferedImage	_resizeImage(BufferedImage src, double ratio)	Resize the buffered image
protected static BufferedImage	_resizeImage(BufferedImage src, int height, int width, int maxHeight, int maxWidth)	Resize the buffered image
static BufferedImage	generateCroppedImage(BufferedImage src, int height, int width)	Crop the image in the center, at the specified dimensions.
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, double ratio)	Generates a BufferedImage with specified size instructions, scaling if necessary.
static BufferedImage	generateThumbnail(BufferedImage src, int height, int width, int maxHeight, int maxWidth)	Generates a BufferedImage with specified size instructions, scaling if necessary.
static BufferedImage	generateThumbnail(BufferedImage src, int height, int width, int maxHeight, int maxWidth, int cropHeight, int cropWidth)	Generates a BufferedImage with specified size instructions, scaling if necessary. If the image should be both cropped and resized, the resizing will be done after the cropping.
static void	generateThumbnail(InputStream is, OutputStream os, String format, double ratio)	Generates a thumbnail from a source InputStream.
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 void	generateThumbnail(InputStream is, OutputStream os, String format, int height, int width, int maxHeight, int maxWidth, int cropHeight, int cropWidth)	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

Field Detail

IMAGE_QUALITY

private static final float IMAGE_QUALITY

See Also:

Constant Field Values

Constructor Detail

ImageHelper

private ImageHelper()

Method Detail

_needsChanges

private static boolean _needsChanges(int height,
                                     int width,
                                     int maxHeight,
                                     int maxWidth,
                                     int cropHeight,
                                     int cropWidth)

_isJpeg

private static boolean _isJpeg(String format)

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,
                                     int cropHeight,
                                     int cropWidth)
                              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. If the image should be both cropped and resized, the resizing will be done after the cropping.

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.

cropHeight - the height of the cropped image. Ignore if negative.

cropWidth - the width of the cropped image. Ignore if negative.

Throws:

IOException - if an error occurs when manipulating streams.

generateThumbnail

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

Generates a BufferedImage with specified size instructions, scaling if necessary.
If the image should be both cropped and resized, the resizing will be done after the cropping.

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.

cropHeight - the height of the cropped image. Ignore if negative.

cropWidth - the width of the cropped image. Ignore if negative.

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

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

generateThumbnail

public static void generateThumbnail(InputStream is,
                                     OutputStream os,
                                     String format,
                                     double ratio)
                              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".

ratio - ratio to resize the image (1 = same size)

Throws:

IOException - if an error occurs when manipulating streams.

generateThumbnail

public static BufferedImage generateThumbnail(BufferedImage src,
                                              double ratio)
                                       throws IOException

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

Parameters:

src - the source image.

ratio - ratio to resize the image (1 = same size)

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 height,
                                                 int width)
                                          throws IOException

Crop the image in the center, at the specified dimensions. The returned BufferedImage shares the same data array as the original image.

Parameters:

src - the source image.

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

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 height,
                                          int width)
                                   throws IOException

Crop the image to the size specified to the center of the image.

Parameters:

src - the source image.

height - the width of the specified rectangular region

width - the height of the specified rectangular region

Returns:

The cropped image as a BufferedImage

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

_resizeImage

protected static BufferedImage _resizeImage(BufferedImage src,
                                            double ratio)
                                     throws IOException

Resize the buffered image

Parameters:

src - the source image

ratio - ratio to resize the image (1 = same size)

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