bmp 및 jpeg 이미지 형식을 Java로 변환하는 방법

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; }

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 it1 = ImageIO.getImageReadersByFormatName("jpeg"); if (it1.hasNext()) { jpegReader = it1.next(); } jpegReader.setInput(fiis); ImageWriter bmpWriter = null; Iterator 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(); } }