修改图片的像素，清晰度

代码

 /*** 改变图片 像素** @param file* @param qality 参数qality是取值0~1范围内  清晰程度  数值越小分辨率越低* @param imageType 图片写出类型 比如 jpg* @return* @throws IOException*/public static File compressPictureByQality(File file, float qality,String imageType) throws IOException {BufferedImage src = null;FileOutputStream out = null;ImageWriter imgWrier;ImageWriteParam imgWriteParams;logger.info("开始设定压缩图片参数");// 指定写图片的方式为 jpgimgWrier = ImageIO.getImageWritersByFormatName(imageType).next();imgWriteParams = new javax.imageio.plugins.jpeg.JPEGImageWriteParam(null);// 要使用压缩，必须指定压缩方式为MODE_EXPLICITimgWriteParams.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);// 这里指定压缩的程度，参数qality是取值0~1范围内，imgWriteParams.setCompressionQuality(qality);imgWriteParams.setProgressiveMode(ImageWriteParam.MODE_DISABLED);ColorModel colorModel = ImageIO.read(file).getColorModel();// ColorModel.getRGBdefault();imgWriteParams.setDestinationType(new javax.imageio.ImageTypeSpecifier(colorModel, colorModel.createCompatibleSampleModel(32, 32)));logger.info("结束设定压缩图片参数");if (!file.exists()) {logger.info("Not Found Img File,文件不存在");throw new FileNotFoundException("Not Found Img File,文件不存在");} else {logger.info("图片转换前大小" + file.length() + "字节");src = ImageIO.read(file);out = new FileOutputStream(file);imgWrier.reset();// 必须先指定 out值，才能调用write方法, ImageOutputStream可以通过任何// OutputStream构造imgWrier.setOutput(ImageIO.createImageOutputStream(out));// 调用write方法，就可以向输入流写图片imgWrier.write(null, new IIOImage(src, null, null),imgWriteParams);out.flush();out.close();logger.info("图片转换后大小" + file.length() + "字节");return file;}}

原图

修改之后的图