Package ca.cgjennings.graphics

Class ImageUtilities

java.lang.Object

ca.cgjennings.graphics.ImageUtilities

public final class ImageUtilities
extends java.lang.Object

Utility methods for creating and converting images, icons, and other graphics. The functionality includes: creating and converting images in certain common formats (particularly the integer (A)RGB formats that the filters in the graphics filters package are optimized for), converting icons to images, adjusting the size of icons, and applying common filter effects to icon images, creating custom Cursors, applying common filters to images, copying images, and adjusting the margins of images (padding, trimming, centreing), computing the ideal scale for an image to fit it within or over a given area, and resampling (resizing) images at high quality.

Since:

2.1

Author:

Chris Jennings

Method Summary

Modifier and Type	Method	Description
static java.awt.image.BufferedImage	alphaComposite(java.awt.image.BufferedImage source, float opacity)	Return a version of this image with an overall transparency change.
static java.awt.image.BufferedImage	center(java.awt.image.BufferedImage source, int width, int height)	Returns an image that centres a source image over a new image of a given size.
static java.awt.image.BufferedImage	copy(java.awt.image.BufferedImage source)	Returns a copy of the image.
static java.awt.image.BufferedImage	createCompatibleIntARGBFormat(java.awt.image.BufferedImage im)	Creates a new image the same size as im which is in TYPE_INT_ARGB format.
static java.awt.image.BufferedImage	createCompatibleIntRGBFormat(java.awt.image.BufferedImage im)	Creates a new image the same size as im which is in either TYPE_INT_RGB or TYPE_INT_ARGB format depending on whether im is opaque.
static java.awt.image.BufferedImage	createCompatibleIntRGBFormat(java.awt.image.BufferedImage im, int width, int height)	Creates a new image with the specified size which is in either TYPE_INT_RGB or TYPE_INT_ARGB format depending on whether im is opaque.
static java.awt.Cursor	createCustomCursor(java.awt.image.BufferedImage image, int hotspotX, int hotspotY)	Deprecated. Use ResourceKit.createCustomCursor(java.lang.String, java.awt.Point, java.lang.String, java.awt.Cursor).
static java.awt.Cursor	createCustomCursor(java.awt.Toolkit toolkit, java.awt.image.BufferedImage image, int hotspotX, int hotspotY, java.lang.String name)	Deprecated. Use ResourceKit.createCustomCursor(java.lang.String, java.awt.Point, java.lang.String, java.awt.Cursor).
static javax.swing.Icon	createDesaturatedIcon(javax.swing.Icon src)	Returns a greyscale version of an icon.
static javax.swing.Icon	createDisabledIcon(javax.swing.Icon src)	Returns a disabled version of an icon.
static java.awt.image.BufferedImage	createDisabledImage(java.awt.image.BufferedImage src)	Returns a disabled version of an image.
static javax.swing.Icon	createGhostedIcon(javax.swing.Icon src)	Returns a ghosted version of an icon.
static javax.swing.Icon	createIconForSize(java.awt.image.BufferedImage image, int size)	Creates an icon from image that is constrained to size by size pixels.
static java.awt.image.BufferedImage	desaturate(java.awt.image.BufferedImage src)	Returns a greyscale version of an image.
static javax.swing.Icon	ensureIconHasSize(javax.swing.Icon icon, int size)	Ensures that the supplied icon has the specified size.
static java.awt.image.BufferedImage	ensureImageHasAlphaChannel(java.awt.image.BufferedImage im)	Returns a version of an image that includes an alpha channel.
static java.awt.image.BufferedImage	ensureImageHasType(java.awt.image.BufferedImage im, int type)	If im does not use the specified pixel format, an equivalent image in that format is returned.
static java.awt.image.BufferedImage	ensureIntRGBFormat(java.awt.Image image)	If im is not in an integer (A)RGB format, returns a new, equivalent image in an integer RGB format.
static java.awt.image.BufferedImage	ensurePremultipliedFormat(java.awt.image.BufferedImage im)	Returns a version of an image that is in an integer (A)RGB format.
static java.awt.image.BufferedImage	flip(java.awt.image.BufferedImage source, boolean horiz, boolean vert)	Returns a mirrored version of the source image.
static java.awt.image.BufferedImage	iconToImage(javax.swing.Icon i)	Returns the visual content of an icon as an image.
static double	idealBoundingScaleForImage(double idealWidth, double idealHeight, double imageWidth, double imageHeight)	Returns the smallest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension and will not be larger than the ideal size in the other dimension.
static float	idealBoundingScaleForImage(float idealWidth, float idealHeight, float imageWidth, float imageHeight)	Returns the smallest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension and will not be larger than the ideal size in the other dimension.
static float	idealBoundingScaleForImage(int idealWidth, int idealHeight, int imageWidth, int imageHeight)	Returns the smallest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension and will not be larger than the ideal size in the other dimension.
static double	idealCoveringScaleForImage(double idealWidth, double idealHeight, double imageWidth, double imageHeight)	Returns the largest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension.
static float	idealCoveringScaleForImage(float idealWidth, float idealHeight, float imageWidth, float imageHeight)	Returns the largest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension.
static float	idealCoveringScaleForImage(int idealWidth, int idealHeight, int imageWidth, int imageHeight)	Returns the largest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension.
static java.awt.image.BufferedImage	imageToBufferedImage(java.awt.Image image)	Returns a BufferedImage that is equivalent to a specified Image.
static java.awt.image.BufferedImage	invert(java.awt.image.BufferedImage source)	Returns a copy of the source image with the colour values inverted.
static boolean	isOpaque(java.awt.image.BufferedImage bi)	Returns true if every pixel in this image is fully opaque.
static java.awt.image.BufferedImage	merge(java.awt.image.BufferedImage... images)	Draws a series of images overtop of each other.
static java.awt.image.BufferedImage	pad(java.awt.image.BufferedImage source, int top, int left, int bottom, int right)	Returns an image that is identical to a source image except that it is padded by blank pixels around the outside.
static java.awt.image.BufferedImage	resample(java.awt.image.BufferedImage src, float factor)	Resample an image by a scaling factor, at a high level of quality.
static java.awt.image.BufferedImage	resample(java.awt.image.BufferedImage src, float factor, boolean multipass, java.lang.Object finalPassHint, java.lang.Object intermediateHint)
static java.awt.image.BufferedImage	resample(java.awt.image.BufferedImage src, int width, int height)	Resample an image to a specified size, at a high level of quality.
static java.awt.image.BufferedImage	resample(java.awt.image.BufferedImage src, int width, int height, boolean multipass, java.lang.Object finalPassHint, java.lang.Object intermediateHint)	Resample an image.
static java.awt.image.BufferedImage	trim(java.awt.image.BufferedImage sourceImage)	Create a trimmed version of the source image that excludes fully transparent (alpha=0) rows and columns around the image's edges.
static java.awt.Image	waitForImage(java.awt.Image im)	Waits for an image to load.

Methods inherited from class java.lang.Object

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

Method Detail

createCompatibleIntRGBFormat

public static java.awt.image.BufferedImage createCompatibleIntRGBFormat(java.awt.image.BufferedImage im)

Creates a new image the same size as im which is in either TYPE_INT_RGB or TYPE_INT_ARGB format depending on whether im is opaque.

Parameters:

im - the image to create a new image for

Returns:

a new image compatible with im but guaranteed to use an 8-bit RGB format

createCompatibleIntRGBFormat

public static java.awt.image.BufferedImage createCompatibleIntRGBFormat(java.awt.image.BufferedImage im,
                                                                        int width,
                                                                        int height)

Creates a new image with the specified size which is in either TYPE_INT_RGB or TYPE_INT_ARGB format depending on whether im is opaque.

Parameters:

im - the image to create a new image for

Returns:

a new image compatible with im but guaranteed to use an 8-bit RGB format

createCompatibleIntARGBFormat

public static java.awt.image.BufferedImage createCompatibleIntARGBFormat(java.awt.image.BufferedImage im)

Creates a new image the same size as im which is in TYPE_INT_ARGB format.

Parameters:

im - the image to create a new image for

Returns:

a new image compatible with im but guaranteed to use 8-bit ARGB format

ensureIntRGBFormat

public static java.awt.image.BufferedImage ensureIntRGBFormat(java.awt.Image image)

If im is not in an integer (A)RGB format, returns a new, equivalent image in an integer RGB format. If im is already in an integer RGB format, returns the original image.

Parameters:

im - the non-null image to be provided in integer RGB format

Returns:

the original image, or a copy converted to a suitable format

ensureImageHasAlphaChannel

public static java.awt.image.BufferedImage ensureImageHasAlphaChannel(java.awt.image.BufferedImage im)

Returns a version of an image that includes an alpha channel. If the source image has an alpha channel, it is returned. Otherwise, a copy is returned.

Parameters:

im - the image to check

Returns:

the original image, or a copy that includes an alpha channel

ensureImageHasType

public static java.awt.image.BufferedImage ensureImageHasType(java.awt.image.BufferedImage im,
                                                              int type)

If im does not use the specified pixel format, an equivalent image in that format is returned. If im is already in the specified format, it is returned unchanged.

Parameters:

im - the image to be provided in the specified format

type - the BufferedImage.TYPE_* value for the desired format

Returns:

the original image, or a copy converted to the requested format

ensurePremultipliedFormat

public static java.awt.image.BufferedImage ensurePremultipliedFormat(java.awt.image.BufferedImage im)

Returns a version of an image that is in an integer (A)RGB format. If the source includes an alpha channel, the returned image will use a premultiplied image type.

Parameters:

im - the image to be provided in the specified format

Returns:

the original image, or a copy in an integer (A)RGB format, with premultiplied alpha if appropriate

createCustomCursor

@Deprecated
public static java.awt.Cursor createCustomCursor(java.awt.image.BufferedImage image,
                                                 int hotspotX,
                                                 int hotspotY)

Deprecated.

Use ResourceKit.createCustomCursor(java.lang.String, java.awt.Point, java.lang.String, java.awt.Cursor).

Defines a new custom cursor for use with the default Toolkit, based on the specified image.

Parameters:

image - the image to use for the cursor

hotspotX - the x-coordinate of the cursor's hotspot (the image offset where clicks occur)

hotspotY - the y-coordinate of the cursor's hotspot

Returns:

a custom cursor as close to the requested form as allowed by the toolkit; if the toolkit does not support custom cursors, the default cursor is returned

createCustomCursor

@Deprecated
public static java.awt.Cursor createCustomCursor(java.awt.Toolkit toolkit,
                                                 java.awt.image.BufferedImage image,
                                                 int hotspotX,
                                                 int hotspotY,
                                                 java.lang.String name)

Deprecated.

Use ResourceKit.createCustomCursor(java.lang.String, java.awt.Point, java.lang.String, java.awt.Cursor).

Defines a new custom cursor for use with a Toolkit, based on the specified image.

Parameters:

toolkit - the toolkit on which to define the cursor (null for default)

image - the image to use for the cursor

hotspotX - the x-coordinate of the cursor's hotspot (the image offset where clicks occur)

hotspotY - the y-coordinate of the cursor's hotspot

name - the custom cursor name, for accessibility, or null to generate a name

Returns:

a custom cursor as close to the requested form as allowed by the toolkit; if the toolkit does not support custom cursors, the default cursor is returned

imageToBufferedImage

public static java.awt.image.BufferedImage imageToBufferedImage(java.awt.Image image)

Returns a BufferedImage that is equivalent to a specified Image. If the image is already a BufferedImage, it is returned unmodified. Otherwise, a new BufferedImage will be created and the contents of the image copied into it. If necessary, the method will wait until the image has finished downloading.

Parameters:

image - the non-null image to convert

Returns:

the original image, converted into a BufferedImage if it is not already of that type

createIconForSize

public static javax.swing.Icon createIconForSize(java.awt.image.BufferedImage image,
                                                 int size)

Creates an icon from image that is constrained to size by size pixels.

The returned icon is guaranteed to be a ThemedIcon.

Parameters:

image - the image to create an icon from

size - the maximum width and height of the icon

Returns:

an icon created from image

ensureIconHasSize

public static javax.swing.Icon ensureIconHasSize(javax.swing.Icon icon,
                                                 int size)

Ensures that the supplied icon has the specified size. If the source icon is null, null is returned. Otherwise, if the icon has the correct dimensions it is returned. If not, but the icon is a ThemedIcon, then a new icon is derived from it. Finally, if no other case applies, an image of the icon will be converted into an icon of the requested size.

Parameters:

icon - the image to create an icon from

size - the desired width and height of the icon

Returns:

an icon of the requested size, or null

iconToImage

public static java.awt.image.BufferedImage iconToImage(javax.swing.Icon i)

Returns the visual content of an icon as an image. If possible, the image will be obtained directly from the icon instance without creating a new image. Note that the size of the image may not match the size of the icon.

Parameters:

i - the icon

Returns:

the content of the icon, as an image

createDisabledIcon

public static javax.swing.Icon createDisabledIcon(javax.swing.Icon src)

Returns a disabled version of an icon.

Parameters:

src - the icon to convert

Returns:

a version of the icon with a suitable "disabled" effect applied

createDisabledImage

public static java.awt.image.BufferedImage createDisabledImage(java.awt.image.BufferedImage src)

Returns a disabled version of an image.

Parameters:

src - the image to convert

Returns:

a version of the image with a suitable default "disabled" effect applied

createGhostedIcon

public static javax.swing.Icon createGhostedIcon(javax.swing.Icon src)

Returns a ghosted version of an icon. Ghosted icons are similar to the original icon, but with every other pixel made transparent in a checkerboard pattern.

Parameters:

src - the icon to convert

Returns:

a version of the icon with a ghosting effect applied

createDesaturatedIcon

public static javax.swing.Icon createDesaturatedIcon(javax.swing.Icon src)

Returns a greyscale version of an icon.

Parameters:

src - the icon to convert

Returns:

a greyscale version of the icon

desaturate

public static java.awt.image.BufferedImage desaturate(java.awt.image.BufferedImage src)

Returns a greyscale version of an image.

Parameters:

src - the image to convert

Returns:

a greyscale version of the image

See Also:

GreyscaleFilter

invert

public static java.awt.image.BufferedImage invert(java.awt.image.BufferedImage source)

Returns a copy of the source image with the colour values inverted. (Black pixels become white, red pixels become cyan, and so on.)

Parameters:

source - the image to invert

Returns:

the inverted image

resample

public static java.awt.image.BufferedImage resample(java.awt.image.BufferedImage src,
                                                    float factor)

Resample an image by a scaling factor, at a high level of quality.

Parameters:

src - the source image

factor - a relative size factor applied to both dimensions

Returns:

a new image at the requested size

resample

public static java.awt.image.BufferedImage resample(java.awt.image.BufferedImage src,
                                                    float factor,
                                                    boolean multipass,
                                                    java.lang.Object finalPassHint,
                                                    java.lang.Object intermediateHint)

resample

public static java.awt.image.BufferedImage resample(java.awt.image.BufferedImage src,
                                                    int width,
                                                    int height)

Resample an image to a specified size, at a high level of quality.

Parameters:

src - the source image

width - the new image width

height - the new image height

Returns:

a new image at the requested size

resample

public static java.awt.image.BufferedImage resample(java.awt.image.BufferedImage src,
                                                    int width,
                                                    int height,
                                                    boolean multipass,
                                                    java.lang.Object finalPassHint,
                                                    java.lang.Object intermediateHint)

Resample an image. If multipass is true, then the method may split the resampling into multiple passes in order to increase the quality of the result. The quality of the interpolation is also controlled by the hint values, which must be one of the RenderingHints.VALUE_INTERPOLATION_* values, or else null. (If a hint is null, a slow area-averaging algorithm will be used.) The hints determine the type of interpolation used at each stage; the final pass hint is always used exactly once (unless the image is already the requested size). The intermediate hint is used for all other passes, if any. The following table shows some suggested combinations of values, in order from fastest/lowest quality to slowest/highest quality:

Suggested resampling combinations

multipass	finalPassHint	intermediateHint
false	VALUE_INTERPOLATION_NEAREST_NEIGHBOUR	null (ignored)
true	VALUE_INTERPOLATION_BILINEAR	VALUE_INTERPOLATION_BILINEAR
true	VALUE_INTERPOLATION_BILINEAR	VALUE_INTERPOLATION_BICUBIC
true	VALUE_INTERPOLATION_BICUBIC	VALUE_INTERPOLATION_BICUBIC

Parameters:

src - the source image

width - the new image width

height - the new image height

multipass - if multiple passes are allowed

finalPassHint - a rendering hint specifying the type of interpolation to use for the final pass

intermediateHint - a rendering hint specifying the type of interpolation to use for intermediate passes, if any

Returns:

a new image at the requested size, or the original image if the new size matches the source image

idealCoveringScaleForImage

public static double idealCoveringScaleForImage(double idealWidth,
                                                double idealHeight,
                                                double imageWidth,
                                                double imageHeight)

Returns the largest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension. The image will either match the ideal size in the other dimension, or else be larger than the other ideal dimension. If the image is opaque, the result is the scaling factor needed to obtain the smallest image with the same aspect ratio that would completely cover the ideal image area.

Parameters:

idealWidth - the width of the area the image must cover

idealHeight - the height of the area the image must cover

imageWidth - the current width of the image to be fitted

imageHeight - the current height of the image to be fitted

Returns:

the scale that would ensure that the image would just cover the specified area

idealCoveringScaleForImage

public static float idealCoveringScaleForImage(float idealWidth,
                                               float idealHeight,
                                               float imageWidth,
                                               float imageHeight)

Returns the largest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension. The image will either match the ideal size in the other dimension, or else be larger than the other ideal dimension. If the image is opaque, the result is the scaling factor to obtain the smallest image with the same aspect ratio that would completely cover the ideal image area.

Parameters:

idealWidth - the width of the area the image must cover

idealHeight - the height of the area the image must cover

imageWidth - the current width of the image to be fitted

imageHeight - the current height of the image to be fitted

Returns:

the scale that would ensure that the image would just cover the specified area

idealCoveringScaleForImage

public static float idealCoveringScaleForImage(int idealWidth,
                                               int idealHeight,
                                               int imageWidth,
                                               int imageHeight)

Returns the largest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension. The image will either match the ideal size in the other dimension, or else be larger than the other ideal dimension. If the image is opaque, the result is the scaling factor to obtain the smallest image with the same aspect ratio that would completely cover the ideal image area.

Parameters:

idealWidth - the width of the area the image must cover

idealHeight - the height of the area the image must cover

imageWidth - the current width of the image to be fitted

imageHeight - the current height of the image to be fitted

Returns:

the scale that would ensure that the image would just cover the specified area

idealBoundingScaleForImage

public static double idealBoundingScaleForImage(double idealWidth,
                                                double idealHeight,
                                                double imageWidth,
                                                double imageHeight)

Returns the smallest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension and will not be larger than the ideal size in the other dimension.

Parameters:

idealWidth - the width of the area the image must just fit within

idealHeight - the height of the area the image must just fit within

imageWidth - the current width of the image to be fitted

imageHeight - the current height of the image to be fitted

Returns:

the scale that just fits the image within the bounds, without any of the image lying outside of the ideal area

idealBoundingScaleForImage

public static float idealBoundingScaleForImage(float idealWidth,
                                               float idealHeight,
                                               float imageWidth,
                                               float imageHeight)

Returns the smallest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension and will not be larger than the ideal size in the other dimension.

Parameters:

idealWidth - the width of the area the image must just fit within

idealHeight - the height of the area the image must just fit within

imageWidth - the current width of the image to be fitted

imageHeight - the current height of the image to be fitted

Returns:

the scale that just fits the image within the bounds, without any of the image lying outside of the ideal area

idealBoundingScaleForImage

public static float idealBoundingScaleForImage(int idealWidth,
                                               int idealHeight,
                                               int imageWidth,
                                               int imageHeight)

Returns the smallest scaling factor that, when multiplied by the given image size, ensures that the image will match the ideal size in at least one dimension and will not be larger than the ideal size in the other dimension. The result is the largest image that fits within the ideal image dimensions without exceeding them, even though there may be extra space around the image on one dimension.

Parameters:

idealWidth - the width of the area the image must just fit within

idealHeight - the height of the area the image must just fit within

imageWidth - the current width of the image to be fitted

imageHeight - the current height of the image to be fitted

Returns:

the scale that just fits the image within the bounds, without any of the image lying outside of the ideal area

copy

public static java.awt.image.BufferedImage copy(java.awt.image.BufferedImage source)

Returns a copy of the image.

Parameters:

source - the image to copy

Returns:

a copy of the image in an integer (A)RGB format

center

public static java.awt.image.BufferedImage center(java.awt.image.BufferedImage source,
                                                  int width,
                                                  int height)

Returns an image that centres a source image over a new image of a given size.

Parameters:

source - the source image

width - the width of the new image

height - the height of the new image

Returns:

an integer (A)RGB image containing the source image such that the centre pixels of the two images are aligned

pad

public static java.awt.image.BufferedImage pad(java.awt.image.BufferedImage source,
                                               int top,
                                               int left,
                                               int bottom,
                                               int right)

Returns an image that is identical to a source image except that it is padded by blank pixels around the outside. The returned image is always of type TYPE_INT_ARGB. Margins can be negative, in which case rows or columns are removed from the outside of the image. If the margins are such that the width or height becomes less than 1, a blank 1 by 1 pixel image is returned. If the margin is 0 on all sides and the image type is suitable, the source image is returned.

Parameters:

source - the source image

top - the number of pixels to add to the top edge

left - the number of pixels to add to the left edge

bottom - the number of pixels to add to the bottom edge

right - the number of pixels to add to the right edge

Returns:

a padded copy of the image

trim

public static java.awt.image.BufferedImage trim(java.awt.image.BufferedImage sourceImage)

Create a trimmed version of the source image that excludes fully transparent (alpha=0) rows and columns around the image's edges. If there are no such rows or columns, returns the original image. If the entire image is fully transparent, returns a 1x1 transparent image.

Parameters:

sourceImage - the image to trim

Returns:

a trimmed version of the image, or the original image if it does not need trimming

See Also:

TrimFilter

flip

public static java.awt.image.BufferedImage flip(java.awt.image.BufferedImage source,
                                                boolean horiz,
                                                boolean vert)

Returns a mirrored version of the source image. If neither parameter is true, the original image is returned. Otherwise, a copy is returned that is flipped horizontally and/or vertically.

Parameters:

source - the image to create a mirrored version of

horiz - if true, the image is mirrored horizontally (i.e., on the y axis)

vert - if true, the image is mirrored vertically (i.e., on the x axis)

Returns:

the mirrored version of the image

See Also:

TurnAndFlipFilter

merge

public static java.awt.image.BufferedImage merge(java.awt.image.BufferedImage... images)

Draws a series of images overtop of each other. The images are drawn in the reverse order of the parameters; that is, the first parameter will be drawn overtop of the second, the second over the third and so forth. The images will be drawn directly onto the last image in the list. If this is null, a new image will be created with a width and height equal to the maximum width and maximum height of all of the other images. The last image in the last (possibly newly created if it was null) is returned from the method.

Parameters:

images - a series of images to paint over each other

Returns:

the bottom image, or a new image if the bottom (last) image was null

Throws:

java.lang.NullPointerException - if a null array is passed in

java.lang.IllegalArgumentException - if the image array has length 0

alphaComposite

public static java.awt.image.BufferedImage alphaComposite(java.awt.image.BufferedImage source,
                                                          float opacity)

Return a version of this image with an overall transparency change. Pixels with an opacity of 1 (that is, 100%) in the source image will have the specified opacity in the destination image; other pixels with have a new opacity equal to their current opacity times the specified value. For example, if the specified opacity is 0.5, and the source pixel has opacity 0.5, its opacity in the output image will be 0.25.

Parameters:

source - the original image

opacity - the alpha level to draw the image at, as a floating point value between 0 and 1

Returns:

a version of the image at the specified transparency (possibly the original image)

isOpaque

public static boolean isOpaque(java.awt.image.BufferedImage bi)

Returns true if every pixel in this image is fully opaque. If the image has no alpha channel, then true is returned immediately. Otherwise, the image is checked pixel-by-pixel.

Parameters:

bi - the image to check

Returns:

true if and only if every pixel is opaque

Throws:

java.lang.NullPointerException - if the image is null

waitForImage

public static java.awt.Image waitForImage(java.awt.Image im)

Waits for an image to load. Generic Image instances, such as those obtained from the Toolkit are designed to load in the background. As a result, certain methods may return wrong or temporary values. This method ensures that a target image is fully loaded (or failed to load) before returning. Note that BufferedImages never load in the background. If passed a BufferedImage this method returns immediately.

Parameters:

im - the image to wait for

Returns:

the image that was passed in