我目前正在尝试使用以下代码将 tiff 图像压缩为较小的 jpg 文件：
public ImageHandler(String srcPath, String destPath, float qual) throws IOException{
this.pathToSourceImage = srcPath;
this.pathToDestImage = destPath;
this.quality = qual;
this.sourceImage = new File(pathToSourceImage);
this.destImage = new File(pathToDestImage);
this.srcInStream = new FileInputStream(sourceImage);
this.destOutStream = new FileOutputStream(destImage);
}
private void compress() throws IOException{
BufferedImage image = ImageIO.read(srcInStream);
System.out.println("Got the bufferedImage");
Iterator<ImageWriter> writers = ImageIO.getImageWritersByFormatName("jpg");
if(!writers.hasNext()){
throw new IllegalStateException("No Writers Found!");
}
ImageWriter writer = (ImageWriter) writers.next();
ImageOutputStream imageOutStream = ImageIO.createImageOutputStream(destOutStream);
writer.setOutput(imageOutStream);
ImageWriteParam param = writer.getDefaultWriteParam();
//Compress at quality
param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
param.setCompressionQuality(quality);
writer.write(null, new IIOImage(image, null, null), param);
srcInStream.close();
destOutStream.close();
imageOutStream.close();
writer.dispose();
}
public static void main(String args[]){
String tifPath = "C:\\00000000.090.tif";
String compressedJpgPath = "C:\\compressed.jpg";
float quality = 0.5f;
try{
ImageHandler testHandler = new ImageHandler(tifPath, compressedJpgPath, quality);
testHandler.compress();
}catch(IOException e){
e.printStackTrace();
}
}
即使我可以让它成功地将源 tif 读入缓冲区，它仍然会引发以下错误：
Exception in thread "main" java.lang.IllegalArgumentException: image == null!
at javax.imageio.IIOImage.<init>(IIOImage.java:109)
at fjimagecompressor.ImageHandler.compress(ImageHandler.java:82)
at fjimagecompressor.ImageHandler.main(ImageHandler.java:99)
在线：
writer.write(null, new IIOImage(image, null, null), param);
即使不是，图像如何将自身报告为空？