基于java的图片文件格式转换和线性缩放

/**
*
* @param img
* @param dest
* @throws JimiException
*/
public void toTIF(Image img, String dest) throws JimiException {
　if (!dest.toLowerCase().trim().endsWith("tif")) {
　　dest += ".tif";
　　System.out.println("Overriding to TIF, output file: " + dest);
　}
　dest = dest.substring(0, dest.lastIndexOf(".")) + ".jpg";
　JimiWriter writer = Jimi.createJimiWriter(dest);
　writer.setSource(img);
　dest = dest.substring(0, dest.lastIndexOf(".")) + ".tif";
　writer.putImage(dest);
}

/**
* 线性改变图片尺寸(可同时改变图片格式)
*
* @param source
* 源文件完整路径
* @param desc
* 目标文件完整路径
* @param ins
* 放大/缩小比率
* @throws JimiException
* @throws IOException
*/
public void changeDimension(String source, String desc, double ins)
throws JimiException, IOException {
　String temp = desc;
　File _file = null;
　if (desc == null || desc.trim().equals(""))
　　desc = source;
　if (!desc.toLowerCase().trim().endsWith("jpg")) {
　　temp = desc.trim() + ".jpg";
　}
　this.toJPG(source, temp, 75);
　_file = new File(temp); // 读入文件

　Image src = javax.imageio.ImageIO.read(_file); // 构造Image对象
　double wideth = (double) src.getWidth(null); // 得到源图宽
　double height = (double) src.getHeight(null); // 得到源图长
　int iWideth = (int) (wideth * ins);
　int iHeight = (int) (height * ins);
　BufferedImage tag = new BufferedImage(iWideth, iHeight,
　BufferedImage.TYPE_INT_RGB);
　tag.getGraphics().drawImage(src, 0, 0, iWideth, iHeight, null); // 绘制缩小后的图

　if (!temp.trim().equals(desc))
　　_file.deleteOnExit();

　if (desc.toLowerCase().trim().endsWith("gif")) {
　　AnimatedGifEncoder e = new AnimatedGifEncoder();
　　e.start(desc);
　　e.addFrame(tag);
　　e.finish();
　} else if (desc.toLowerCase().trim().endsWith("tif") || desc.toLowerCase().trim().endsWith("tiff")) {
　　this.toTIF(tag, desc);
　} else {
　　JimiWriter writer = Jimi.createJimiWriter(desc);
　　writer.setSource(tag);
　　writer.putImage(desc);
　}
}