imageutil.java

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package com.j2medev.httpme.tools;

import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;

/**
 * Uitlity class to handle Image, httpme 0.1 does not use it.
 * @author mingjava
 * @version 0.1 05/06/2006
 */
public class ImageUtil {
    
    /** Creates a new instance of ImageUtil */
    public ImageUtil() {
    }
    
    /**
     * create a thumbnail image from orignal image
     * @param image the orignal image
     * @param width new image's width
     * @return the new thumbnail image
     */
    public static Image createThumbnail(Image image,int width) {
        int sourceWidth = image.getWidth();
        int sourceHeight = image.getHeight();

        int thumbWidth = width;
        int thumbHeight = -1;
        
        if (thumbHeight == -1)
            thumbHeight = thumbWidth * sourceHeight / sourceWidth;
        
        Image thumb = Image.createImage(thumbWidth, thumbHeight);
        Graphics g = thumb.getGraphics();
        
        for (int y = 0; y < thumbHeight; y++) {
            for (int x = 0; x < thumbWidth; x++) {
                g.setClip(x, y, 1, 1);
                int dx = x * sourceWidth / thumbWidth;
                int dy = y * sourceHeight / thumbHeight;
                g.drawImage(image, x - dx, y - dy, Graphics.LEFT | Graphics.TOP);
            }
        }
        Image immutableThumb = Image.createImage(thumb);
        return immutableThumb;
    }
    
    
    private static byte[] int2byte(int[] data) {
        byte[] buffer = new byte[4*data.length];
        for(int i=0; i<data.length; i++) {
            int p = data[i];
            buffer[i*4+0] = (byte)((p & 0xff000000)>>>24);
            buffer[i*4+1] = (byte)((p & 0xff0000)>>>16);
            buffer[i*4+2] = (byte)((p & 0xff00)>>>8);
            buffer[i*4+3] = (byte)((p & 0xff));
        }
        return buffer;
    }

    private static int[] byte2int(byte[] data) {
        int[] buffer = new int[data.length/4];
        for(int i=0; i<data.length/4; i++) {
            int a = 0xff & data[i*4+0];
            int r = 0xff & data[i*4+1];
            int g = 0xff & data[i*4+2];
            int b = 0xff & data[i*4+3];
            buffer[i] = (a << 24) | (r << 16) | (g << 8) | b;
        }
        return buffer;
    }
    
}