package ImageTest; import java.awt.Graphics2D; import java.awt.RenderingHints; import java.awt.geom.AffineTransform; import java.awt.image.BufferedImage; import java.awt.image.ColorModel; import java.awt.image.WritableRaster; import java.io.File; import java.io.IOException; import javax.imageio.ImageIO; public class Test { /** * 为图片文件生成缩略图 * @param args */ public static void main(String[] args) { try { //参数1(源图片路径),参数2 (缩略图路径),参数3(缩略图宽)参数4(缩略图高) Test.saveImageAsJpg("E:\\QQ20120612154244.gif", "E:\\test.jpg", 400, 400); } catch (IOException e) { e.printStackTrace(); } } /** * 生成缩略图 * @param fromFileStr 源图片路径 * @param saveToFileStr 缩略图路径 * @param width 缩略图的宽 * @param hight 缩略图的高 * @throws IOException */ public static void saveImageAsJpg(String fromFileStr,String saveToFileStr,int width,int hight) throws IOException { BufferedImage srcImage; String imgType="JPEG"; if(fromFileStr.toLowerCase().endsWith(".png")){ imgType="PNG"; } File saveFile=new File(saveToFileStr); File fromFile=new File(fromFileStr); srcImage=ImageIO.read(fromFile); if(width>0||hight>0){ srcImage=resize(srcImage,width,hight); } ImageIO.write(srcImage, imgType, saveFile); } /** * 将源图片的BufferedImage对象生成缩略图 * @param source 源图片的BufferedImage对象 * @param targetW 缩略图的宽 * @param targetH 缩略图的高 * @return */ private static BufferedImage resize(BufferedImage source, int targetW, int targetH) { int type=source.getType(); BufferedImage target=null; double sx=(double)targetW/source.getWidth(); double sy=(double)targetH/source.getHeight(); if(sx>sy) { sx=sy; targetW=(int)(sx*source.getWidth()); }else{ sy=sx; targetH=(int)(sy*source.getHeight()); } if(type==BufferedImage.TYPE_CUSTOM){ ColorModel cm=source.getColorModel(); WritableRaster raster=cm.createCompatibleWritableRaster(targetW, targetH); boolean alphaPremultiplied=cm.isAlphaPremultiplied(); target=new BufferedImage(cm,raster,alphaPremultiplied,null); }else{ target=new BufferedImage(targetW, targetH,type); } Graphics2D g=target.createGraphics(); g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY); g.drawRenderedImage(source, AffineTransform.getScaleInstance(sx, sy)); g.dispose(); return target; } }
转载地址:http://blog.csdn.net/hehe9737/article/details/7656308