java压缩图片内存大小，但不改变分辨率大小，第二种方式

/**
* @Title: compressPic 
* @Description: 压缩图片,通过压缩图片质量，保持原图大小
* @param  quality:0-1    
* @return byte[] 
* @throws
*/
public static byte[] compressPic(byte[] imageByte,float quality) {
byte[] inByte = null;
try {
ByteArrayInputStream byteInput = new ByteArrayInputStream(imageByte);
Image img = ImageIO.read(byteInput);
float newWidth = img.getWidth(null);
float newHeight = img.getHeight(null);


Image image = img.getScaledInstance((int) newWidth,(int) newHeight, Image.SCALE_SMOOTH);


// 缩放图像
BufferedImage tag = new BufferedImage((int) newWidth,
(int) newHeight, BufferedImage.TYPE_INT_RGB);
Graphics2D g = tag.createGraphics();
g.drawImage(image, 0, 0, null); // 绘制缩小后的图
g.dispose();
ByteArrayOutputStream out = new ByteArrayOutputStream(imageByte.length);
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out); 
            JPEGEncodeParam jep=JPEGCodec.getDefaultJPEGEncodeParam(tag); 
            /* 压缩质量 */ 
            jep.setQuality((float)0.6, true); 
            encoder.encode(tag, jep); 
            inByte = out.toByteArray();
            out.close(); 

} catch (IOException ex) {
ex.printStackTrace();
}
return inByte;
}