Java如何实现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();
}
}
