图片处理

最新推荐文章于 2024-10-13 22:19:10 发布

最新推荐文章于 2024-10-13 22:19:10 发布 · 105 阅读

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根据帖子：http://www.iteye.com/topic/40971 整理

图片缩小处理

第一种方式缩小后质量很差

第二，三种方式缩小后很好

对图片的缩放一定要用 Image下的 getScaledInstance

Graphics下的还有 AffineTransform下的缩放都是针对"图形"而不是"图像"的

图形就是用java类画的线条等简单几何图形

import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import org.apache.commons.io.FileUtils;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class Pic {

public static void reduceImg(String imgsrc, String imgdist, int widthdist,
            int heightdist) {
        try {
            File srcfile = new File(imgsrc);
            if (!srcfile.exists()) {
                return;
            }
            Image src = javax.imageio.ImageIO.read(srcfile);
            int width = src.getWidth(null);
            int height = src.getHeight(null);

            if (width == widthdist && height == heightdist) {
                FileUtils.copyFile(new File(imgsrc), new File(imgdist));
                return;
            }


            double ws = (double) widthdist / (double) width;

            double hs = (double) heightdist / (double) height;

            BufferedImage tag=null;

            tag = new BufferedImage((int) widthdist, (int) heightdist,
                    BufferedImage.TYPE_INT_RGB);

            Graphics2D g2d=(Graphics2D)tag.getGraphics();

第一种方式

//            AffineTransform at=AffineTransform.getScaleInstance(ws,hs);
//            RenderingHints qualityHints = new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
//            g2d.transform(at);
//            qualityHints.put(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
//            qualityHints.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
//
//            qualityHints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
//
//            g2d.setRenderingHints(qualityHints);
// g2d.drawImage(src, 0, 0, null);

第2种方式
g2d.drawImage(src.getScaledInstance(widthdist, heightdist, Image.SCALE_SMOOTH), 0, 0, null);

第3种方式
//          /         tag.getGraphics().drawImage(src.getScaledInstance(widthdist, heightdist, Image.SCALE_AREA_AVERAGING), 0, 0, null);
            FileOutputStream out = new FileOutputStream(imgdist);
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
            encoder.encode(tag);
            out.close();

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

public static void main(String[] args)
{
  Pic.reduceImg("c:/pic/1.gif","c:/pic/11.gif",48,48);
}

}