Java 图像压缩
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/22812325/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Java Image compression
提问by ali muhammad
From our application we fetch images (jpeg/png) from a third party service, after download we want to save these images as compressed.
从我们的应用程序中，我们从第三方服务获取图像 (jpeg/png)，下载后我们希望将这些图像保存为压缩文件。
Can any one please guide how to compress images in Java ?
任何人都可以指导如何在 Java 中压缩图像吗？
回答by Marco13
JPG and PNG images already arecompressed, so it's not entirely clear what your intention is. However, in general, you can write images with ImageIO:
JPG 和 PNG 图像已被压缩，因此您的意图尚不完全清楚。但是，通常，您可以使用以下命令编写图像ImageIO：
ImageIO.write(image, "jpg", outputStream);
(or "png", analogously). By default, this does not allow you to select the compression level(that is, the trade-off between file size and image quality). In order to write a JPG file with a different than the default compression, you can use a utility method like this:
（或"png"，类似地）。默认情况下，这不允许您选择压缩级别（即文件大小和图像质量之间的权衡）。为了编写与默认压缩不同的 JPG 文件，您可以使用如下实用方法：
public static void writeJPG(
BufferedImage bufferedImage,
OutputStream outputStream,
float quality) throws IOException
{
Iterator<ImageWriter> iterator =
ImageIO.getImageWritersByFormatName("jpg");
ImageWriter imageWriter = iterator.next();
ImageWriteParam imageWriteParam = imageWriter.getDefaultWriteParam();
imageWriteParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
imageWriteParam.setCompressionQuality(quality);
ImageOutputStream imageOutputStream =
new MemoryCacheImageOutputStream(outputStream);
imageWriter.setOutput(imageOutputStream);
IIOImage iioimage = new IIOImage(bufferedImage, null, null);
imageWriter.write(null, iioimage, imageWriteParam);
imageOutputStream.flush();
}
