Java实现的图片高质量缩放类定义与用法示例

本文实例讲述了java实现的图片高质量缩放类定义与用法。分享给大家供大家参考，具体如下：

找了很多都不理想，最后找个到老外写的，不得不承认老外写的确实牛b。

package com.test;
import com.sun.image.codec.jpeg.jpegimageencoder;
import com.sun.image.codec.jpeg.jpegcodec;
import com.sun.image.codec.jpeg.jpegencodeparam;
import javax.swing.*;
import java.io.file;
import java.io.fileoutputstream;
import java.io.ioexception;
import java.awt.*;
import java.awt.image.bufferedimage;
import java.awt.image.kernel;
import java.awt.image.convolveop;
public class imageutil {
  public static void resize(file originalfile, file resizedfile,
      int newwidth, float quality) throws ioexception {
    if (quality > 1) {
      throw new illegalargumentexception(
          "quality has to be between 0 and 1");
    }
    imageicon ii = new imageicon(originalfile.getcanonicalpath());
    image i = ii.getimage();
    image resizedimage = null;
    int iwidth = i.getwidth(null);
    int iheight = i.getheight(null);
    if (iwidth > iheight) {
      resizedimage = i.getscaledinstance(newwidth, (newwidth * iheight)
          / iwidth, image.scale_smooth);
    } else {
      resizedimage = i.getscaledinstance((newwidth * iwidth) / iheight,
          newwidth, image.scale_smooth);
    }
    // this code ensures that all the pixels in the image are loaded.
    image temp = new imageicon(resizedimage).getimage();
    // create the buffered image.
    bufferedimage bufferedimage = new bufferedimage(temp.getwidth(null),
        temp.getheight(null), bufferedimage.type_int_rgb);
    // copy image to buffered image.
    graphics g = bufferedimage.creategraphics();
    // clear background and paint the image.
    g.setcolor(color.white);
    g.fillrect(0, 0, temp.getwidth(null), temp.getheight(null));
    g.drawimage(temp, 0, 0, null);
    g.dispose();
    // soften.
    float softenfactor = 0.05f;
    float[] softenarray = { 0, softenfactor, 0, softenfactor,
        1 - (softenfactor * 4), softenfactor, 0, softenfactor, 0 };
    kernel kernel = new kernel(3, 3, softenarray);
    convolveop cop = new convolveop(kernel, convolveop.edge_no_op, null);
    bufferedimage = cop.filter(bufferedimage, null);
    // write the jpeg to a file.
    fileoutputstream out = new fileoutputstream(resizedfile);
    // encodes image as a jpeg data stream
    jpegimageencoder encoder = jpegcodec.createjpegencoder(out);
    jpegencodeparam param = encoder
        .getdefaultjpegencodeparam(bufferedimage);
    param.setquality(quality, true);
    encoder.setjpegencodeparam(param);
    encoder.encode(bufferedimage);
  } // example usage
  public static void main(string[] args) throws ioexception {
//    file originalimage = new file("c:\\11.jpg");
//    resize(originalimage, new file("c:\\11-0.jpg"),150, 0.7f);
//    resize(originalimage, new file("c:\\11-1.jpg"),150, 1f);
     file originalimage = new file("c:\\1207.gif");
     resize(originalimage, new file("c:\\1207-0.jpg"),150, 0.7f);
     resize(originalimage, new file("c:\\1207-1.jpg"),150, 1f);
  }
}

更多java相关内容感兴趣的读者可查看本站专题：《java图片操作技巧汇总》、《java日期与时间操作技巧汇总》、《java操作dom节点技巧总结》、《java文件与目录操作技巧汇总》及《java数据结构与算法教程》。

希望本文所述对大家java程序设计有所帮助。