tif图片压缩

tif图片在ImageIo.read获取时，返回为空，导致无法使用，百度了很久，很多人说jai可以，便去看了下，总结如下：

public static void CompressPic(String srcPath, long maxSize) throws Exception {
double cutPercent = 0.1;
File file = new File(srcPath);
//读取tif图
SeekableStream s = new FileSeekableStream(srcPath);
TIFFDecodeParam tifParam = new TIFFDecodeParam();
ImageDecoder dec = ImageCodec.createImageDecoder("TIFF", s, tifParam);
RenderedImage renderedImage = dec.decodeAsRenderedImage(); // 图片解码
//转为bufferedImage对象
BufferedImage bufferedImage = ImageUtil.convertRenderedImage(renderedImage);
int width = bufferedImage.getWidth(null);
int height = bufferedImage.getHeight(null);
long fileLength = file.length();
while ((fileLength / 1024) >= maxSize) {
width = (int) (width * (1 - cutPercent));
height = (int) (height * (1 - cutPercent));
BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR);
tag.getGraphics().drawImage(bufferedImage, 0, 0, width, height, null); // 绘制缩小后的图
FileOutputStream deskImage = new FileOutputStream(srcPath); // 输出到文件流
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(deskImage);
encoder.encode(tag); // 近JPEG编码
deskImage.close();

File file1 = new File(srcPath);
BufferedImage bufferedImage1 = ImageIO.read(new FileInputStream(file1));
width = bufferedImage1.getWidth(null);
height = bufferedImage1.getHeight(null);
fileLength = file1.length();
}
}

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这是tif的renderedImage对象转为Image对象的方法

public class ImageUtil {

@SuppressWarnings({ "unchecked", "rawtypes" })
public static BufferedImage convertRenderedImage(RenderedImage img) {
if (img instanceof BufferedImage) {
return (BufferedImage) img;
}
ColorModel cm = img.getColorModel();
int width = img.getWidth();
int height = img.getHeight();
WritableRaster raster = cm.createCompatibleWritableRaster(width, height);
boolean isAlphaPremultiplied = cm.isAlphaPremultiplied();
Hashtable properties = new Hashtable();
String[] keys = img.getPropertyNames();
if (keys != null) {
for (int i = 0; i < keys.length; i++) {
properties.put(keys[i], img.getProperty(keys[i]));
}
}
BufferedImage result = new BufferedImage(cm, raster, isAlphaPremultiplied, properties);
img.copyData(raster);
return result;
}
}

希望未来的自己更加努力！