java文件比例缩小放大
1首先添加修改图片宽度和高度的方法
public static void reduceImg(String imgsrc, int widthdist, int heightdist) {
try {
File srcfile = new File(imgsrc);
if (!srcfile.exists()) {
return;
}
// 载入图片文件
Image src = javax.imageio.ImageIO.read(srcfile);
int w0 = src.getWidth(null); // 得到源图宽
int h0 = src.getHeight(null); // 得到源图长
BufferedImage tag = new BufferedImage((int) widthdist,
(int) heightdist, BufferedImage.TYPE_INT_RGB);
// 保存文件
// 绘制缩小后的图
tag.getGraphics().drawImage(
src.getScaledInstance(widthdist, heightdist,
java.awt.Image.SCALE_SMOOTH), 0, 0, null);
// tag.getGraphics().drawImage(src.getScaledInstance(widthdist,
// heightdist, Image.SCALE_AREA_AVERAGING), 0, 0, null);
// 标注水印
// int x = widthdist/10*8; //水印位置(x,y)
// int y = heightdist/10*8;
// jpg_logo( tag , x , y );
// 重命名并新建图片
String oleName = imgsrc.substring(imgsrc.lastIndexOf(".") - 1,
imgsrc.lastIndexOf("."));
String newName = oleName + "v";
String imgdist = imgsrc.replace(oleName, newName);
// 输出到文件流
FileOutputStream out = new FileOutputStream(imgdist);
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
// 近JPEG编码
encoder.encode(tag);
out.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
2按比例去缩小图片
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