Package eu.hoefel

Class ArrayToPNG

java.lang.Object

eu.hoefel.ArrayToPNG

public class ArrayToPNG
extends Object

Convert a 2d array into a PNG image.

Author:

Udo Hoefel

Field Summary

Fields

Modifier and Type	Field	Description
static double[][]	COLORMAP1	Default jet-like colormap for use with array2Image and dumpAsPng.

Constructor Summary

Constructors

Constructor	Description
ArrayToPNG()

Method Summary

Modifier and Type	Method	Description
static BufferedImage	array2Image(float[][] a, double[][] colormap, double[][] alpha, boolean interpolatedColors)	Creates an image from an array using a specified (optional) colormap and (optional) transparency alpha.
static void	dumpAsPng(float[][] a, double[][] colormap, double[][] alpha, String filename, boolean interpolatedColors)	Dumps the array as a png file, using a specified (optional) colormap and (optional) transparency alpha.
static void	dumpAsPng(float[][] a, String filename)	Dumps the array as a png file'

Methods inherited from class java.lang.Object

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

Field Detail

COLORMAP1

public static double[][] COLORMAP1

Default jet-like colormap for use with array2Image and dumpAsPng. size: [R,G,B][nPoints]

Constructor Detail

ArrayToPNG

public ArrayToPNG()

Method Detail

dumpAsPng

public static void dumpAsPng(float[][] a,
                             String filename)

Dumps the array as a png file'

Parameters:

a - The array

filename - The name of the image file.

dumpAsPng

public static void dumpAsPng(float[][] a,
                             double[][] colormap,
                             double[][] alpha,
                             String filename,
                             boolean interpolatedColors)

Dumps the array as a png file, using a specified (optional) colormap and (optional) transparency alpha. The corresponding colors to the values in the array will be linearly interpolated according to the colormap. If the alpha array is given, the corresponding alpha value for the pixel i,j will be set to alpha[i][j], where alpha must be [0,1].

Parameters:

a - The array

colormap - A 3xm array, of [0,1] values. colormap[0][i] is red, colormap[1][i] green, colormap[2][i] blue.

alpha - An array with the same dimensions as a containing transparency values. If null transparency will be 0.

array2Image

public static BufferedImage array2Image(float[][] a,
                                        double[][] colormap,
                                        double[][] alpha,
                                        boolean interpolatedColors)

Creates an image from an array using a specified (optional) colormap and (optional) transparency alpha. The corresponding colors to the values in the array will be linearly interpolated according to the colormap. If the alpha array is given, the corresponding alpha value for the pixel i,j will be set to alpha[i][j], where alpha must be [0,1].

Parameters:

a - The array

colormap - [3][m] values in the range [0,1]. colormap[0][i] is red, colormap[1][i] green, colormap[2][i] blue. Can be null (default; jet-like).

alpha - An array with the same dimensions as a containing transparency values. If null transparency will be 0.

interpolatedColors - true: interpolate colormap linearly; false: find nearest color; NaN is mapped to first entry in colormap

Returns:

A BufferedImage object that can be later saved with for example ImageIO.write(image, "PNG", new File("my.png"));