如何在Java中实现jpeg-lossess?如何实现jpeg无损?
ImageWriter writer = (ImageWriter) ImageIO.getImageWritersByFormatName("JPEG-LS").next();
ImageWriteParam param = writer.getDefaultWriteParam();
param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
param.setCompressionType("JPEG-LS");
writer.setOutput(ImageIO.createImageOutputStream(new File("C:\\Users\\RileyRen\\Desktop\\123.jpg")));
writer.write(null, new IIOImage(subBufferedImage, null, null), param);
将抛出一个异常:
Exception in thread "main"
java.lang.IllegalArgumentException: Unknown compression type!
at javax.imageio.ImageWriteParam.setCompressionType(ImageWriteParam.java:1041)
at com.demandforce.ImageCrop.main(ImageCrop.java:59)
的param.getCompressionTypes()
只打印[JPEG]
。
使用JAI
(1.1.3版本):
PlanarImage input = JAI.create("fileload", "C:\\Users\\RileyRen\\Desktop\\test.jpg");
ParameterBlock pb = new ParameterBlock();
pb.addSource(input);
pb.add(x);
pb.add(y);
pb.add(width);
pb.add(height);
PlanarImage output = JAI.create("crop",pb,null);
JAI.create("filestore",output,"C:\\Users\\RileyRen\\Desktop\\123.jpg","JPEG-LS");
此外,抛出异常:
Exception in thread "main"
java.lang.IllegalArgumentException: FileStore The specified format has no associated registered ImageCodec.
at javax.media.jai.JAI.createNS(JAI.java:1087)
at javax.media.jai.JAI.create(JAI.java:973)
at javax.media.jai.JAI.create(JAI.java:1621)
at com.demandforce.ImageCrop.main(ImageCrop.java:103)
你可以写一个样吗?
尝试'System.out.println(Arrays.toString(param.getCompressionTypes()))'。 –
只有[JPEG] ... –
奇怪。你能打印第一类ImageWriter的类名吗?如果您真的拥有来自JAI的CLibJPEGImageWriter(唯一能够支持JPEG-LS AFAIK的作家),它应该支持JPEG-LS和JPEG-LOSSLESS。注意:这些是不同的算法,而不是同义词。 – haraldK