今天遇到的两个问题：
图片本如图1所示，
java处理后，变成了图2所示，严重失真，偏红，怎么办？
以上直接上关键代码：
原来处理的代码:
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class BufferedImageTool {
public static void resize(String imgPath, double factor) throws IOException {
File file = new File(imgPath);
BufferedImage bufferedImage = ImageIO.read(file);
int width = (int) (bufferedImage.getWidth() * factor);
int height = (int) (bufferedImage.getHeight() *factor);
BufferedImage bufferedImage1 = resize(bufferedImage, width, height);
File outfile = new File("image.jpg");
ImageIO.write(bufferedImage1, "jpg", outfile);
}
/**
*/
public static BufferedImage resize(BufferedImage img, int newW, int newH) {
Image tmp = img.getScaledInstance(newW, newH, Image.SCALE_SMOOTH);
BufferedImage dimg = new BufferedImage(newW, newH, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = dimg.createGraphics();
g2d.drawImage(tmp, 0, 0, null);
g2d.dispose();
return dimg;
}
}
后来找到了一个库，效果非常好，处理完后的图片大小比图2还稍微小一点。
但却没有色差，几乎跟原图完全一样，效果很好。
直接上代码，
依赖 thumbnailator库。
<!-- https://mvnrepository.com/artifact/net.coobird/thumbnailator -->
<dependency>
<groupId>net.coobird</groupId>
<artifactId>thumbnailator</artifactId>
<version>0.4.14</version>
</dependency>
上代码：
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import net.coobird.thumbnailator.Thumbnails;
/**
*
*/
public class ThumbnailsTool {
public static void resize(String imgPath, double factor) throws IOException {
File localTempFile = new File(imgPath);
BufferedImage bufferedImage = ImageIO.read(localTempFile);
int width = (int) (bufferedImage.getWidth() * factor);
int height = (int) (bufferedImage.getHeight() * factor);
// BufferedImage 第三方库压缩图片画幅。JDK自带的会有严重色差
Thumbnails.of(localTempFile)
.size(width, height)
.outputFormat("jpg")
.toFile(new File("image2.jpg"));
}
}
入口Main函数:
import image.ImageHelper;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.util.UUID;
import net.coobird.thumbnailator.Thumbnails;
public class Starter {
public static void main(String[] args) throws IOException, URISyntaxException {
String imageUrl = "D:\\MyJava\\java-image\\sky.jpg";
//1. BufferedImage的形式处理
BufferedImageTool.resize(imageUrl, 0.5);
//2. Thumbnails 方式的处理
ThumbnailsTool.resize(imageUrl, 0.5);
}
}
产生的文件截图如下：
源码这里有: https://gitee.com/codejam_org/java-image
