com.vaadin.testbench.screenshot

Class ImageUtil

java.lang.Object

com.vaadin.testbench.screenshot.ImageUtil

public class ImageUtil
extends Object

These image utility functions are for internal use only.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ImageUtil.ImageProperties Contains ImageUtil-internal information about an image.

Constructor Summary

Constructors

Constructor and Description
ImageUtil()

Method Summary

Modifier and Type	Method and Description
static BufferedImage	cloneImage(BufferedImage sourceImage) Clones the given BufferedImage
static int[]	createSampleBuffer() Create a 16x16 sample buffer with space for 4 color bands
static List<BufferedImage>	cropToBeSameSize(BufferedImage image1, BufferedImage image2) Resize images to be same size.
static String	encodeImageToBase64(BufferedImage image) Encodes target image to a Base64 string
static int[]	getBlock(ImageUtil.ImageProperties properties, int x, int y, int[] result, int[] sample) Returns the 16x16 RGB block starting at (x,y) from the given image
static ImageUtil.ImageProperties	getImageProperties(BufferedImage image) Extract magical image properties used by the getBlock function.
static double	getLuminance(int rgb) Get luminance value for the given RGB value.
static boolean	imagesSameSize(BufferedImage image1, BufferedImage image2) Check whether canvas sizes match.

Methods inherited from class java.lang.Object

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

Constructor Detail

ImageUtil

public ImageUtil()

Method Detail

encodeImageToBase64

public static String encodeImageToBase64(BufferedImage image)

Encodes target image to a Base64 string

Parameters:

image - BufferedImage to encode to String

Returns:

Base64 encoded String of image

getLuminance

public static double getLuminance(int rgb)

Get luminance value for the given RGB value. The RGB value is assumed to be taking up the low 24 bits of the integer sample, with red shifted by 16 bits, green by 8 bits, and blue by 0 bits, all added together. This is the only channel order supported by this method, attempting to use any other channel orders will result in incorrect luminance values.

Parameters:

rgb - RGB value

Returns:

luminance value

imagesSameSize

public static boolean imagesSameSize(BufferedImage image1,
                                     BufferedImage image2)

Check whether canvas sizes match.

Parameters:

image1 - an image

image2 - an image

Returns:

true if the images have the same height and width, false otherwise

cropToBeSameSize

public static List<BufferedImage> cropToBeSameSize(BufferedImage image1,
                                                   BufferedImage image2)

Resize images to be same size. The size is determined by the minimum height and minimum width of the images.

Parameters:

image1 - an image.

image2 - an image.

Returns:

a list containing two images with the same dimensions

createSampleBuffer

public static final int[] createSampleBuffer()

Create a 16x16 sample buffer with space for 4 color bands

Returns:

sample buffer array

getImageProperties

public static final ImageUtil.ImageProperties getImageProperties(BufferedImage image)

Extract magical image properties used by the getBlock function.

Parameters:

image - a BufferedImage

Returns:

an ImageProperties descriptor object

getBlock

public static final int[] getBlock(ImageUtil.ImageProperties properties,
                                   int x,
                                   int y,
                                   int[] result,
                                   int[] sample)

Returns the 16x16 RGB block starting at (x,y) from the given image

Parameters:

properties - The properties of the image (image + metadata)

x - The x coordinate of the block (in pixels)

y - The y coordinate of the block (in pixels)

result - A sample buffer (32 bits per pixel) for storing the resulting block, or null (a new buffer will be created)

sample - A sample buffer for storing intermediate values, or null (a new buffer will be created). This parameter is provided mainly for speed (providing it eliminates unnecessary block allocations).

Returns:

An array of RGB values for the block

cloneImage

public static BufferedImage cloneImage(BufferedImage sourceImage)

Clones the given BufferedImage

Parameters:

sourceImage - The image to copy

Returns:

A copy of sourceImage