Java 实现图片固定宽度缩放

我就是我 2023-07-25 10:00 31阅读 0赞

## 1.方法一 jdk自带包 ##

/**
         *
         * @param imageUrl 原图片地址
         * @param outFile 新图片文件
         * @param newWidth 指定宽度
         * @param quality 图片质量比(<1)
         */
        public static void resize(String imageUrl, File outFile, int newWidth, float quality) {
            if (quality > 1) {
                throw new IllegalArgumentException(
                        "Quality has to be between 0 and 1");
            }
            FileOutputStream out = null;
            try {
                File originalFile = new File(imageUrl);
                ImageIcon ii = new ImageIcon(originalFile.getCanonicalPath());
                Image i = ii.getImage();
                Image resizedImage = null;
    
                int iWidth = i.getWidth(null);
                int iHeight = i.getHeight(null);
    
                //if (iWidth > iHeight) {
                resizedImage = i.getScaledInstance(newWidth, (newWidth * iHeight)
                        / iWidth, Image.SCALE_SMOOTH);
            /*} else {
                resizedImage = i.getScaledInstance((newWidth * iWidth) / iHeight,
                        newWidth, Image.SCALE_SMOOTH);
            }*/
    
                // This code ensures that all the pixels in the image are loaded.
                Image temp = new ImageIcon(resizedImage).getImage();
    
                // Create the buffered image.
                BufferedImage bufferedImage = new BufferedImage(temp.getWidth(null),
                        temp.getHeight(null), BufferedImage.TYPE_INT_RGB);
    
                // Copy image to buffered image.
                Graphics g = bufferedImage.createGraphics();
    
                // Clear background and paint the image.
                g.setColor(Color.white);
                g.fillRect(0, 0, temp.getWidth(null), temp.getHeight(null));
                g.drawImage(temp, 0, 0, null);
                g.dispose();
    
                // Soften.
                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);
    
                // Write the jpeg to a file.
                out = new FileOutputStream(outFile);
                ImageIO.write(bufferedImage, "jpg", out);
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (out != null) {
                    try {
                        out.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }

### 方法二     google之Thumbnails图片等比压缩 ###

maven之pom.xml依赖

<dependency>  
    <groupId>net.coobird</groupId>  
    <artifactId>thumbnailator</artifactId>  
    <version>0.4.8</version>  
</dependency>

/**
         * @param imageUrl 原图片url
         * @param newWidth 压缩后宽度
         * @param quality  图片质量(<1)
         * @return
         */
    public String imageZoom(String imageUrl, int newWidth, float quality) {
            ImageIcon imageIcon = new ImageIcon(imageUrl);
            int iconWidth = imageIcon.getIconWidth();
            int iconHeight = imageIcon.getIconHeight();
            try {
                //压缩后图片保存地址
                String imagePath = ""E:/PICTURE/4.jpg"
                Integer height = (newWidth * iconHeight) / iconWidth;
                Thumbnails.of(imageUrl).size(newWidth, height).outputQuality(quality).toFile(imagePath);
                return imagePath;
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }

更多方法可参考：[https://blog.csdn.net/qq\_33101675/article/details/75093372?depth\_1-utm\_source=distribute.pc\_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4&utm\_source=distribute.pc\_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4][https_blog.csdn.net_qq_33101675_article_details_75093372_depth_1-utm_source_distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4_utm_source_distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4]

[https_blog.csdn.net_qq_33101675_article_details_75093372_depth_1-utm_source_distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4_utm_source_distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4]: https://blog.csdn.net/qq_33101675/article/details/75093372?depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4&utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4