java ImageIO处理图片文件时报错Unsupported Image Type及颜色失真

心已赠人 2022-02-28 14:16 698阅读 0赞

java的ImageIO类默认能对RGB格式的图片进行处理，当遇到CMYK格式的图片时就会报错Unsupported Image Type，或者图片处理后变成了大片花花绿绿/黑漆漆的丢失了原来的颜色。即JDK自带的ImageIO类默认情况下不能处理CMYK格式的图片。

解决上面的图片处理问题，引入开源项目[https://github.com/haraldk/TwelveMonkeys][https_github.com_haraldk_TwelveMonkeys]即可解决：按之前的方式使用ImageIO,不需要使用额外的API，只有引入类似下面的依赖即可。

<dependencies>
    	<dependency>
    		<groupId>com.twelvemonkeys.imageio</groupId>
    		<artifactId>imageio-jpeg</artifactId>
    		<version>3.4.1</version>
    	</dependency>
    	<dependency>
    		<groupId>com.twelvemonkeys.imageio</groupId>
    		<artifactId>imageio-tiff</artifactId>
    		<version>3.4.1</version>
    	</dependency>
    	<dependency>
    		<groupId>com.twelvemonkeys.common</groupId>
    		<artifactId>common-lang</artifactId>
    		<version>3.4.1</version>
    	</dependency>
    	<dependency>
    		<groupId>com.twelvemonkeys.common</groupId>
    		<artifactId>common-io</artifactId>
    		<version>3.4.1</version>
    	</dependency>
    	<dependency>
    		<groupId>com.twelvemonkeys.common</groupId>
    		<artifactId>common-image</artifactId>
    		<version>3.4.1</version>
    	</dependency>
    	<dependency>
    		<groupId>com.twelvemonkeys.imageio</groupId>
    		<artifactId>imageio-core</artifactId>
    		<version>3.4.1</version>
    	</dependency>
    	<dependency>
    		<groupId>com.twelvemonkeys.imageio</groupId>
    		<artifactId>imageio-metadata</artifactId>
    		<version>3.4.1</version>
    	</dependency>
    </dependencies>

另外，图片处理除了使用jdk自带的ImageIO类之外，也有一些开源项目方便处理图片文件，如项目 [https://github.com/coobird/thumbnailator][https_github.com_coobird_thumbnailator]，有简单方便的API直接可用。

下面是一个使用ImageIO类的图片处理示例：

import java.awt.Image;
    import java.awt.image.BufferedImage;
    import java.io.Closeable;
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.IOException;
    
    import javax.imageio.ImageIO;
    
    public class ImageCompress {
    	private Image image;
    	private int width;
    	private int height;
    	private String fileName;
    
    	public ImageCompress(File file, String fileName) throws IOException {
    		this.fileName = fileName;
    		image = ImageIO.read(file); // 构造Image对象
    		width = image.getWidth(null); // 得到源图宽
    		height = image.getHeight(null); // 得到源图长
    	}
    
    	public void resizeFix(int w, int h) throws IOException {
    		if (width / height > w / h) {
    			resizeByWidth(w);
    		} else {
    			resizeByHeight(h);
    		}
    	}
    
    	public void resizeByWidth(int w) throws IOException {
    		if (width <= w)
    			return;
    		int h = (int) (height * w / width);
    		resize(w, h);
    	}
    
    	/**
    	 * 以高度为基准，等比例缩放图片
    	 * 
    	 * @param h
    	 *            int 新高度
    	 */
    	public void resizeByHeight(int h) throws IOException {
    		int w = (int) (width * h / height);
    		resize(w, h);
    	}
    
    	/**
    	 * 强制压缩/放大图片到固定的大小
    	 * 
    	 * @param w int 新宽度
    	 * @param h int 新高度
    	 */
    	public void resize(int w, int h) throws IOException {
    		// SCALE_SMOOTH 的缩略算法 生成缩略图片的平滑度的 优先级比速度高 生成的图片质量比较好 但速度慢
    		File file = new File(fileName);
    		BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
    		bi.getGraphics().drawImage(image.getScaledInstance(w, h, Image.SCALE_AREA_AVERAGING), 0, 0, null); // 绘制缩小后的图
    		FileOutputStream output = null;
    		try {
    			output = new FileOutputStream(file); // 输出到文件流
    			ImageIO.write(bi, fileName.substring(fileName.lastIndexOf('.') + 1), output);
    		} catch (Exception e) {
    			e.printStackTrace();
    		} finally {
    			close(output);
    		}
    	}
    
    	private void close(Object... obj) {
    		try {
    			if (obj != null) {
    				for (int i = 0; i < obj.length; i++) {
    					if (obj[i] != null) {
    						if (obj[i] instanceof Closeable) {
    							Closeable c = (Closeable) obj[i];
    							c.close();
    						}
    					}
    				}
    			}
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    
    	public static void main(String[] args) {
    		// 批量将E:/home/image目录下的文件做压缩处理，输出到E:/home/image_out目录
    		File src = new File("E:/home/image");
    		String fileName = "E:/home/image_out/";
    		File[] listFiles = src.listFiles();
    		for (File file : listFiles) {
    			String name = file.getName().toLowerCase();
    			if (name.endsWith(".jpg") || name.endsWith(".jpeg") || name.endsWith(".gif") || name.endsWith(".png")) {
    				try {
    					ImageCompress image = new ImageCompress(file, fileName + file.getName());
    					image.resizeByWidth(360);
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    			}
    		}
    	}
    
    }

[https_github.com_haraldk_TwelveMonkeys]: https://github.com/haraldk/TwelveMonkeys
[https_github.com_coobird_thumbnailator]: https://github.com/coobird/thumbnailator