j2me之图片翻转和透明等的处理代码

    /**
     * 获得img的半透明图像
     * @param alpha ：alpha通道值, 必须在0到255之间
     * 
     * 注：在修改alpha值时，先用或运算 | 0xff000000 使其alpha为0xff。
     * 再执行且运算，使其alpha值变为所传参数alpha。
     */
    private Image createAlphaImage(Image img, int alpha)
    {
        int width = img.getWidth();
        int height = img.getHeight();
        int[] argb =newint[width * height];
        img.getRGB(argb, 0, width, 0, 0, width, height);
        int temp = (alpha <<24) |0x00ffffff; 
        for (int i =0; i < argb.length; i++) {
            argb[i] = (argb[i] |0xff000000) & temp; 
        }
        return Image.createRGBImage(argb, width, height, true);            
    }
    
    
    
    /**
     * 获得img的变色图像 -- 只用某些位的颜色
     * 比如：color = 0x00ff00. 则返回图像的色值为原来的green位的值。
     * 放开两条打印语句，可以清晰的看到色值变化情况。
     */
    private Image createColorImage(Image img, int color)
    {
        int width = img.getWidth();
        int height = img.getHeight();
        int[] argb =newint[width * height];
        img.getRGB(argb, 0, width, 0, 0, width, height);
        
        for (int i =0; i < argb.length; i++) {
//            System.out.print(Integer.toHexString(argb[i]) + "   ,   ");
            argb[i] = argb[i] & color; 
//            System.out.println(Integer.toHexString(argb[i]));
        }
        return Image.createRGBImage(argb, width, height, false);            
    }
    
    
    
    
    /**
     * 获得img的倒立图像(竖直翻转)
     */
    private Image createReversalImage(Image img)
    {
        int width = img.getWidth();
        int height = img.getHeight();
        int[] argb =newint[width * height];
        img.getRGB(argb, 0, width, 0, 0, width, height);
        
        int[] argb2 =newint[width * height];
        int row =0;
        int column =0;
        int index =0;
        for (int i =0; i < argb.length; i++) {
            row = i / width;
            column = i % width;
            index = (height - row -1) * width + column;
            argb2[i] = argb[index] ; 
        }
        return Image.createRGBImage(argb2, width, height, false);            
    }
    
    /**
     * 获得img的水平翻转图像
     */
    private Image createMirrorImage(Image img)
    {
        int width = img.getWidth();
        int height = img.getHeight();
        int[] argb =newint[width * height];
        img.getRGB(argb, 0, width, 0, 0, width, height);
        
        int[] argb2 =newint[width * height];
        int row =0;
        int column =0;
        int index =0;
        for (int i =0; i < argb.length; i++) {
            row = i / width;
            column = i % width;
            index = row * width + (width -1- column);
            argb2[i] = argb[index] ; 
        }
        return Image.createRGBImage(argb2, width, height, false);            
    }
    
    
    /**
     * 获得img逆时针转90度后的图像
     */
    private Image createImage_TRANS_ROT90(Image img)
    {
        int width = img.getWidth();
        int height = img.getHeight();
        int[] argb =newint[width * height];
        img.getRGB(argb, 0, width, 0, 0, width, height);
        
        int[] argb2 =newint[width * height];
        int row =0;
        int column =0;
        int index =0;
        for (int i =0; i < argb.length; i++) {
            row = i / width;
            column = i % width;
            index = (width - column -1) * height + row;
            argb2[index] = argb[i] ; 
        }
        return Image.createRGBImage(argb2, height, width, false);            
    }
    
    
    /**
     * 获得img顺时针转90度后的图像(相当于逆时针转270度)
     */
    private Image createImage_TRANS_ROT270(Image img)
    {
        int width = img.getWidth();
        int height = img.getHeight();
        int[] argb =newint[width * height];
        img.getRGB(argb, 0, width, 0, 0, width, height);
        
        int[] argb2 =newint[width * height];
        int row =0;
        int column =0;
        int index =0;
        for (int i =0; i < argb.length; i++) {
            row = i / width;
            column = i % width;
            index = column * height + height -1- row;
            argb2[index] = argb[i] ; 
        }
        return Image.createRGBImage(argb2, height, width, false);            
    }