java 图像 大小变换

java 图像 大小转换

? public static? void writeImageIO(InputStream inputStream,OutputStream outputStream,int nw){
??? ??? ?try {
???????????? AffineTransform transform = new AffineTransform();
???????????? BufferedImage bis = ImageIO.read(inputStream);
???????????? int w = bis.getWidth();
???????????? int h = bis.getHeight();
???????????? double scale = (double)w/h;
???????????? int nh = (nw*h)/w ;
???????????? double sx = (double)nw/w;
???????????? double sy = (double)nh/h;
???????????? transform.setToScale(sx,sy);
???????????? System.out.println(w + " " +h);
???????????? AffineTransformOp ato = new AffineTransformOp(transform,null);
???????????? BufferedImage bid = new BufferedImage(nw,nh,BufferedImage.TYPE_3BYTE_BGR);
???????????? ato.filter(bis,bid);
???????????? ImageIO.write(bid,"jpg",outputStream);
???????? } catch(Exception e) {
???????????? e.printStackTrace();
???????? }
??? }