ImageMagick JMagick 进行基本图像处理的一个类详解编程语言

JMagick是一个开源API，利用JNI(Java NativeInterface)技术实现了对ImageMagickAPI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。

JMagickHandler.java

/** 
 *  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 
 
    } 
 
}