Java实现bmp和jpeg图片格式互转

缺乏、安全感 2024-03-26 07:03 70阅读 0赞

#### 文章目录 ####

*  Java实现bmp和jpeg图片格式互转
 *   *  Bmp转Jpeg
     *  Jpeg转Bmp

## Java实现bmp和jpeg图片格式互转 ##

### Bmp转Jpeg ###

public static String bmp2Jpeg(String filePath, String outPath) {
        
    	try {
        
    		long start = System.currentTimeMillis();
    		// 加载bmp图片
    		File file = new File(filePath);
    		Image img = ImageIO.read(file);
    		BufferedImage tag = new BufferedImage(img.getWidth(null), img.getHeight(null), BufferedImage.TYPE_INT_RGB);
    		tag.getGraphics().drawImage(img.getScaledInstance(img.getWidth(null), img.getHeight(null), Image.SCALE_SMOOTH), 0, 0, null);
    
    		// 输出为Jpeg
    		FileOutputStream out = new FileOutputStream(outPath);
    		// JPEGImageEncoder可适用于其他图片类型的转换
    		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
    		encoder.encode(tag);
    		out.close();
    		
    		log.info("bmp 转 JPEG，共耗时：  " + (System.currentTimeMillis() - start) + " 毫秒");
    		return outPath;
    	} catch (IOException e) {
        
    		e.printStackTrace();
    	}
    		return outPath;
    	}

### Jpeg转Bmp ###

public static void jpeg2Bmp(String inputPath, String outputPath) {
        
    	try {
        
    		long start = System.currentTimeMillis();
    	
    		// 加载Jpeg图片资源
    		FileImageInputStream fiis = new FileImageInputStream(new File(inputPath));
    		FileImageOutputStream fios = new FileImageOutputStream(new File(outputPath));
    		ImageReader jpegReader = null;
    		Iterator<ImageReader> it1 = ImageIO.getImageReadersByFormatName("jpeg");
    		if (it1.hasNext()) {
        
    		    jpegReader = it1.next();
    		}
    		jpegReader.setInput(fiis);
    		
    		ImageWriter bmpWriter = null;
    		Iterator<ImageWriter> it2 = ImageIO.getImageWritersByFormatName("bmp");
    		if (it2.hasNext()) {
        
    		    bmpWriter = it2.next();
    		}
    		bmpWriter.setOutput(fios);
    		BufferedImage br = jpegReader.read(0);
    		bmpWriter.write(br);
    		fiis.close();
    		fios.close();
    		
    		log.info("jpeg 转 bmp，共耗时：" + (System.currentTimeMillis() - start) + " 毫秒");
    	} catch (IOException e) {
        
    		e.printStackTrace();
    	}
    }