j2me工具类：PalettedImage调色板类

该方法网上可以找到，我添加了一个重载函数：
public Image getPalettedImage(String path, int[] originalColors,
int[] palettedColors)
三个参数依次为图片路径、需要改变的旧颜色值、新的颜色值，注意这2个参数都为数组，长度必须一致，这样可以一次改变多种颜色。

用法：
PalettedImage p=new PalettedImage();
Image newImage=p.getPalettedImage("/Humans121.png", new int[]{0x0000ff}, new int[]{0x00ff00});
...
g.drawImage(newImage, 0, 0, 0);

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.microedition.lcdui.Image;

public class PalettedImage {

	public Image getPalettedImage(String path, int[] originalColors,
			int[] palettedColors) {
		InputStream is = null;
		ByteArrayOutputStream baos = null;
		try {
			is = getClass().getResourceAsStream(path);
			baos = new ByteArrayOutputStream();
			int ch = 0;
			while ((ch = is.read()) != -1) {
				baos.write(ch);
			}
		} catch (IOException ioe) {
			System.out.println(ioe);
		} finally {
			try {
				if (baos != null)
					baos.close();
				if (is != null)
					is.close();
			}
			catch (IOException e) {
				System.out.println(e);
			}
		}
		return getPalettedImage(baos.toByteArray(), originalColors,
				palettedColors);
	}
	/*
	 * 原始图片的byte数组，以及需要替换颜色的颜色值还有目标颜色值就行了。 因为可以同时替换多个颜色，所以输入参数是代表颜色的整形的数组。
	 * 总之，要保证原始颜色与目标颜色一一对应就好了
	 */
    public Image getPalettedImage(byte[] data, int[] originalColors,
            int[] palettedColors) {
        byte[] tempData = new byte[data.length];
        System.arraycopy(data, 0, tempData, 0, data.length);
        Image img = null;
        int[] parameter = { 0, 0, 0 };
        analyze(tempData, parameter);
        for (int i = 0; i < originalColors.length; i++) {
            replaceColor(tempData, parameter, originalColors[i],
                    palettedColors[i]);
        }
        fillData(tempData, parameter);
        try {
            img = Image.createImage(tempData, 0, data.length);
        } catch (Exception e) {
            System.out.println("getPalettedImage  &&  " + e.toString());
        }
        return img;
    }

    private void analyze(byte[] data, int[] para) {
        int offset = 8;
        int chunkLen = 0;
        while (data[offset + 4] != 0x50 || data[offset + 5] != 0x4c
                || data[offset + 6] != 0x54 || data[offset + 7] != 0x45) {
            chunkLen = readInt(data, offset);
            offset += (4 + 4 + chunkLen + 4);
        }
        chunkLen = readInt(data, offset);
        para[2] = chunkLen / 3;
        para[0] = offset + 8;
        para[1] = offset + 8 + chunkLen;
    }

    private int readInt(byte[] data, int offset) {
        return ((data[offset] & 0xFF) << 24)
                | ((data[offset + 1] & 0xFF) << 16)
                | ((data[offset + 2] & 0xFF) << 8) | (data[offset + 3] & 0xFF);
    }

    private void replaceColor(byte[] data, int[] para, int oldColor,
            int newColor) {
        byte rr = (byte) ((oldColor >> 16) & 0xff);
        byte gg = (byte) ((oldColor >> 8) & 0xff);
        byte bb = (byte) (oldColor & 0xff);
        for (int i = 0, offset = para[0], temp = 0; i < para[2]; i++, offset += 3) {
            if (rr == data[offset] && gg == data[offset + 1]
                    && bb == data[offset + 2]) {
                data[offset] = (byte) ((newColor >> 16) & 0xff);
                data[offset + 1] = (byte) ((newColor >> 8) & 0xff);
                data[offset + 2] = (byte) (newColor & 0xff);
                break;
            }
        }
    }

    private void fillData(byte[] data, int[] para) {
        int checksum = update_crc(data, para[0] - 4, para[2] * 3 + 4);
        data[para[1]] = (byte) ((checksum >> 24) & 0xff);
        data[para[1] + 1] = (byte) ((checksum >> 16) & 0xff);
        data[para[1] + 2] = (byte) ((checksum >> 8) & 0xff);
        data[para[1] + 3] = (byte) ((checksum) & 0xff);
    }

    private int update_crc(byte[] buf, int off, int len) {
        int c = 0xffffffff;
        int n, k;
        int xx;
        int[] crc_table = new int[256];
        for (n = 0; n < 256; n++) {
            xx = n;
            for (k = 0; k < 8; k++) {
                if ((xx & 1) == 1) {
                    xx = 0xedb88320 ^ (xx >>> 1);
                } else {
                    xx = xx >>> 1;
                }
            }
            crc_table[n] = xx;
        }

        for (n = off; n < len + off; n++) {
            c = crc_table[(c ^ buf[n]) & 0xff] ^ (c >>> 8);
        }
        return (c ^ 0xffffffff);
    }

}