Java将图片压缩为原来的一半

Java将图片压缩为原来的一半

思路：

1.获取源图片的尺寸

2.设置目标图片的尺寸

3.打开源图片

4.基于源图片生成目标图片

ps: 在linux上无法使用JPEGImageEncoder ，因此需要修改代码，使用ImageIO代替JPEGImageEncoder

/*JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

sLogger.info("create encoder done");

encoder.encode(outImage);

sLogger.info("encoder done");*/

ImageIO.write(outImage, "jpg", out);

out.flush();

out.close();

/**

* 压缩为input的1/2

* @param filesrc

* @param outsrc

*/

public static void composePic(String inFileName, String outFileName) {

try {

File inFile = new File(inFileName);

Image inImage = javax.imageio.ImageIO.read(inFile);

//get the input image's width and height

int input_width = inImage.getWidth(null);

int input_height = inImage.getHeight(null);

System.out.println("input_width = " + input_width);

System.out.println("input_height = " + input_height);

//set the output image's width and height

int out_width = input_width/2;

int out_height = input_height/2;

BufferedImage outImage = new BufferedImage(out_width, out_height,

BufferedImage.TYPE_INT_RGB);//an image with 8-bit RGB color

Graphics2D g2d = outImage.createGraphics();

g2d.drawImage(inImage, 0, 0, out_width, out_height, null);

g2d.setComposite(AlphaComposite.getInstance(

AlphaComposite.SRC_ATOP, 1.0f)); // 透明度设置开始

g2d.setComposite(AlphaComposite

.getInstance(AlphaComposite.SRC_OVER)); // 透明度设置 结束

FileOutputStream out = new FileOutputStream(outFileName);

JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

encoder.encode(outImage);

out.close();

} catch (Exception e) {

e.printStackTrace();

}

}