java指定宽度等比例压缩图片

悠悠 2022-07-28 05:29 283阅读 0赞

最近做项目需要用到图片压缩技术，在这里整理下做个分享。

需要注意的是如果要压缩的图片太大，就需要修改JDK的默认内存了。废话不多说，直接上代码。

import java.awt.Color;
    import java.awt.Graphics;
    import java.awt.Image;
    import java.awt.image.BufferedImage;
    import java.awt.image.ConvolveOp;
    import java.awt.image.Kernel;
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.IOException;
     
    import javax.swing.ImageIcon;
     
    import com.sun.image.codec.jpeg.JPEGCodec;
    import com.sun.image.codec.jpeg.JPEGEncodeParam;
    import com.sun.image.codec.jpeg.JPEGImageEncoder;
     
    /**
     * 
     * 图片压缩工具类
     * @author 李锋镝
     *
     */
    public class ImageUtil {
         
        /**
         * 
         * @param originalFile  原文件
         * @param resizedFile  压缩目标文件
         * @param newWidth  压缩后的图片宽度
         * @param quality  压缩质量（0到1之间，越高质量越好）
         * @throws IOException
         */
        public static void resize(File originalFile, File resizedFile,  
                int newWidth, float quality) throws IOException {  
       
            if (quality > 1) {  
                throw new IllegalArgumentException(  
                        "Quality has to be between 0 and 1");  
            }  
       
            ImageIcon ii = new ImageIcon(originalFile.getCanonicalPath());  
            Image i = ii.getImage();  
            Image resizedImage = null;  
       
            int iWidth = i.getWidth(null);  
            System.out.println("iWidth:"+iWidth);
            int iHeight = i.getHeight(null);  
            System.out.println("iHeight:"+iHeight);
            if (iWidth > iHeight) {  
                resizedImage = i.getScaledInstance(newWidth, (newWidth * iHeight)  
                        / iWidth, Image.SCALE_SMOOTH);  
            } else {  
                resizedImage = i.getScaledInstance((newWidth * iWidth) / iHeight,  
                        newWidth, Image.SCALE_SMOOTH);  
            }  
       
            // 获取图片中的所有像素
            Image temp = new ImageIcon(resizedImage).getImage();  
       
            // 创建缓冲
            BufferedImage bufferedImage = new BufferedImage(temp.getWidth(null),  
                    temp.getHeight(null), BufferedImage.TYPE_INT_RGB);  
       
            // 复制图片到缓冲流中
            Graphics g = bufferedImage.createGraphics();  
       
            // 清除背景并开始画图
            g.setColor(Color.white);  
            g.fillRect(0, 0, temp.getWidth(null), temp.getHeight(null));  
            g.drawImage(temp, 0, 0, null);  
            g.dispose();
       
            // 柔和图片.  
            float softenFactor = 0.05f;  
            float[] softenArray = { 0, softenFactor, 0, softenFactor,  
                    1 - (softenFactor * 4), softenFactor, 0, softenFactor, 0 };  
            Kernel kernel = new Kernel(3, 3, softenArray);  
            ConvolveOp cOp = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null);  
            bufferedImage = cOp.filter(bufferedImage, null);  
       
            FileOutputStream out = new FileOutputStream(resizedFile);  
       
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);  
       
            JPEGEncodeParam param = encoder  
                    .getDefaultJPEGEncodeParam(bufferedImage);  
       
            param.setQuality(quality, true);  
       
            encoder.setJPEGEncodeParam(param);  
            encoder.encode(bufferedImage);
            bufferedImage.flush();
            out.close();
        } 
       
        //测试
        public static void main(String[] args) throws IOException {  
             File originalImage = new File("H:\\000.jpg");  
             resize(originalImage, new File("H:\\1207-0.jpg"),500, 0.7f);  
             resize(originalImage, new File("H:\\1207-1.jpg"),500, 1f);  
        }  
    }

最后，大家要注意一定要关闭文件输出流。

原文地址：[java指定宽度等比例压缩图片][java]

个人博客地址：[李锋镝的个人博客][Link 1]

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