本文实例讲述了jmagick实现基本图像处理的类。分享给大家供大家参考。具体分析如下：
jmagick是一个开源api，利用jni(java native interface)技术实现了对 imagemagick api的java访问接口,因此也将比纯java实现的图片操作函数在速度上要快。
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/**
* jmagickhandler.java
*
* author: winter lau
* 2007-7-11
*/
package com.eportal.img;
import java.awt.dimension;
import java.io.file;
import org.apache.commons.io.fileutils;
import com.gif4j.gifdecoder;
import com.gif4j.gifencoder;
import com.gif4j.gifimage;
import com.gif4j.giftransformer;
import dlog.common.util.stringutils;
import magick.imageinfo;
import magick.magickexception;
import magick.magickimage;
/**
* 使用jmagick进行图像处理
*/
class jmagickhandler {
private final static int default_quality = 90;
protected jmagickhandler(){}
private final static threadlocal<mymagickimage> tlocal = new threadlocal<mymagickimage>();
private string lastsrc = null;
/**
* 清除线程本地存储信息
*/
private synchronized mymagickimage getmagickimage(string src) throws exception {
mymagickimage mi = tlocal.get();
if(mi != null && stringutils.equals(src, lastsrc))
return mi;
else if(mi != null)
tlocal.remove();
this.lastsrc = src;
imageinfo info = new imageinfo(src);
mi = new mymagickimage(info);
tlocal.set(mi);
return mi;
}
@override
public void cleanup() {
mymagickimage mi = tlocal.get();
if(mi != null)
mi.destroyimages();
tlocal.remove();
}
@override
public imageextinfo getimageinfo(string src) throws exception {
try{
magickimage image = this.getmagickimage(src);
imageextinfo ext = new imageextinfo();
dimension dim = image.getdimension();
ext.setwidth((int)dim.getwidth());
ext.setheight((int)dim.getheight());
ext.setsize(image.sizeblob());
ext.setanimated(image.isanimatedimage());
return ext;
}catch(magickexception e){
return new purejavahandler().getimageinfo(src);
}
}
private final static boolean hasunicode(string str){
return str.getbytes().length != str.length();
}
@override
public void resize(string src, string dest, int width, int height, int quality) throws exception {
boolean u_src = hasunicode(src);
mymagickimage image;
file srctmp = null;
if(u_src){
srctmp = file.createtempfile("jmagick_s_" + src.hashcode(), null);
fileutils.copyfile(new file(src), srctmp);
image = this.getmagickimage(srctmp.getabsolutepath());
}
else
image = this.getmagickimage(src);
image.getimageinfo().setquality((quality>0)?quality:default_quality);
magickimage scaledimage = null;
try{
if(image.isanimatedimage()){
gifimage gifimage = gifdecoder.decode(new file(src));
gifimage newgif = giftransformer.resize(gifimage, width, height, false);
gifencoder.encode(newgif, new file(dest));
}
else{//others
scaledimage = image.scaleimage(width, height);
scaledimage.setimageformat("jpeg");
scaledimage.profileimage("*", null);
boolean u_dest = hasunicode(dest);
if(u_dest){
file tmp = file.createtempfile("jmagick_d_" + dest.hashcode(), null);
scaledimage.setfilename(tmp.getabsolutepath());
scaledimage.writeimage(image.getimageinfo());
fileutils.copyfile(tmp, new file(dest));
fileutils.forcedelete(tmp);
}
else{
scaledimage.setfilename(dest);
scaledimage.writeimage(image.getimageinfo());
}
}
}finally{
if(srctmp != null) fileutils.forcedelete(srctmp);
if(scaledimage != null)
scaledimage.destroyimages();
}
}
@override
public void rotate(string src, string dest, double degrees) throws exception {
boolean u_src = hasunicode(src);
mymagickimage image;
file srctmp = null;
if(u_src){
srctmp = file.createtempfile("jmagick_s_" + src.hashcode(), null);
fileutils.copyfile(new file(src), srctmp);
image = this.getmagickimage(srctmp.getabsolutepath());
}
else
image = this.getmagickimage(src);
try{
magickimage rotateimg = image.rotateimage(degrees);
rotateimg.profileimage("*", null);
boolean u_dest = hasunicode(dest);
if(u_dest){
file tmp = file.createtempfile("jmagick_d_" + dest.hashcode(), null);
rotateimg.setfilename(tmp.getabsolutepath()); // convert to png
rotateimg.writeimage(image.getimageinfo());
rotateimg.destroyimages();
fileutils.copyfile(tmp, new file(dest));
fileutils.forcedelete(tmp);
}
else{
rotateimg.setfilename(dest); // convert to png
rotateimg.writeimage(image.getimageinfo());
rotateimg.destroyimages();
}
}finally{
if(srctmp != null)
fileutils.forcedelete(srctmp);
}
}
private static class mymagickimage extends magickimage {
private imageinfo imageinfo;
public imageinfo getimageinfo() {
return imageinfo;
}
public mymagickimage(imageinfo info) throws magickexception{
super(info);
this.imageinfo = info;
}
}
@override
public void cropimage(string src, int width, int height, int point,
int point2, string dst) throws exception {
// todo auto-generated method stub
}
}
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