JAVA生成图片缩略图、JAVA截取图片局部内容
package com.ares.image.test; import java.awt.Color; import java.awt.Graphics; import java.awt.Image; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.util.Arrays; import javax.imageio.ImageIO; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.ares.slf4j.test.Slf4jUtil; /** * <p>Title: ImageUtil </p> * <p>Description: 使用JDK原生态类生成图片缩略图和裁剪图片 </p> * <p>Email: icerainsoft@hotmail.com </p> * @author Ares * @date 2014年10月28日 上午10:24:26 */ public class ImageUtil { static { Slf4jUtil.buildSlf4jUtil().loadSlf4j(); } private Logger log = LoggerFactory.getLogger(getClass()); private static String DEFAULT_PREVFIX = "thumb_"; private static Boolean DEFAULT_FORCE = false; /** * <p>Title: thumbnailImage</p> * <p>Description: 根据图片路径生成缩略图 </p> * @param imagePath 原图片路径 * @param w 缩略图宽 * @param h 缩略图高 * @param prevfix 生成缩略图的前缀 * @param force 是否强制按照宽高生成缩略图(如果为false，则生成最佳比例缩略图) */ public void thumbnailImage(File imgFile, int w, int h, String prevfix, boolean force){ if(imgFile.exists()){ try { // ImageIO 支持的图片类型 : [BMP, bmp, jpg, JPG, wbmp, jpeg, png, PNG, JPEG, WBMP, GIF, gif] String types = Arrays.toString(ImageIO.getReaderFormatNames()); String suffix = null; // 获取图片后缀 if(imgFile.getName().indexOf(".") > -1) { suffix = imgFile.getName().substring(imgFile.getName().lastIndexOf(".") + 1); }// 类型和图片后缀全部小写，然后判断后缀是否合法 if(suffix == null || types.toLowerCase().indexOf(suffix.toLowerCase()) < 0){ log.error("Sorry, the image suffix is illegal. the standard image suffix is {}." + types); return ; } log.debug("target image's size, width:{}, height:{}.",w,h); Image img = ImageIO.read(imgFile); if(!force){ // 根据原图与要求的缩略图比例，找到最合适的缩略图比例 int width = img.getWidth(null); int height = img.getHeight(null); if((width*1.0)/w < (height*1.0)/h){ if(width > w){ h = Integer.parseInt(new java.text.DecimalFormat("0").format(height * w/(width*1.0))); log.debug("change image's height, width:{}, height:{}.",w,h); } } else { if(height > h){ w = Integer.parseInt(new java.text.DecimalFormat("0").format(width * h/(height*1.0))); log.debug("change image's width, width:{}, height:{}.",w,h); } } } BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB); Graphics g = bi.getGraphics(); g.drawImage(img, 0, 0, w, h, Color.LIGHT_GRAY, null); g.dispose(); String p = imgFile.getPath(); // 将图片保存在原目录并加上前缀 ImageIO.write(bi, suffix, new File(p.substring(0,p.lastIndexOf(File.separator)) + File.separator + prevfix +imgFile.getName())); } catch (IOException e) { log.error("generate thumbnail image failed.",e); } }else{ log.warn("the image is not exist."); } } public void thumbnailImage(String imagePath, int w, int h, String prevfix, boolean force){ File imgFile = new File(imagePath); thumbnailImage(imgFile, w, h, prevfix, force); } public void thumbnailImage(String imagePath, int w, int h, boolean force){ thumbnailImage(imagePath, w, h, DEFAULT_PREVFIX, force); } public void thumbnailImage(String imagePath, int w, int h){ thumbnailImage(imagePath, w, h, DEFAULT_FORCE); } public static void main(String[] args) { new ImageUtil().thumbnailImage("imgs/Tulips.jpg", 100, 150); } }
效果：（原图是电脑"图片"文件夹下的郁金香图片，大小1024*768，生成的图片为200*150大小，保持4:3的比例）
package com.ares.image.test; import java.awt.Color; import java.awt.Graphics; import java.awt.Image; import java.awt.image.BufferedImage; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.OutputStream; import java.util.Arrays; import javax.imageio.ImageIO; import javax.imageio.ImageReadParam; import javax.imageio.ImageReader; import javax.imageio.stream.ImageInputStream; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.ares.slf4j.test.Slf4jUtil; /** * <p>Title: ImageUtil </p> * <p>Description: </p> * <p>Email: icerainsoft@hotmail.com </p> * @author Ares * @date 2014年10月28日 上午10:24:26 */ public class ImageUtil { static { Slf4jUtil.buildSlf4jUtil().loadSlf4j(); } private Logger log = LoggerFactory.getLogger(getClass()); private static String DEFAULT_THUMB_PREVFIX = "thumb_"; private static String DEFAULT_CUT_PREVFIX = "cut_"; private static Boolean DEFAULT_FORCE = false; /** * <p>Title: cutImage</p> * <p>Description: 根据原图与裁切size截取局部图片</p> * @param srcImg 源图片 * @param output 图片输出流 * @param rect 需要截取部分的坐标和大小 */ public void cutImage(File srcImg, OutputStream output, java.awt.Rectangle rect){ if(srcImg.exists()){ java.io.FileInputStream fis = null; ImageInputStream iis = null; try { fis = new FileInputStream(srcImg); // ImageIO 支持的图片类型 : [BMP, bmp, jpg, JPG, wbmp, jpeg, png, PNG, JPEG, WBMP, GIF, gif] String types = Arrays.toString(ImageIO.getReaderFormatNames()).replace("]", ","); String suffix = null; // 获取图片后缀 if(srcImg.getName().indexOf(".") > -1) { suffix = srcImg.getName().substring(srcImg.getName().lastIndexOf(".") + 1); }// 类型和图片后缀全部小写，然后判断后缀是否合法 if(suffix == null || types.toLowerCase().indexOf(suffix.toLowerCase()+",") < 0){ log.error("Sorry, the image suffix is illegal. the standard image suffix is {}." + types); return ; } // 将FileInputStream 转换为ImageInputStream iis = ImageIO.createImageInputStream(fis); // 根据图片类型获取该种类型的ImageReader ImageReader reader = ImageIO.getImageReadersBySuffix(suffix).next(); reader.setInput(iis,true); ImageReadParam param = reader.getDefaultReadParam(); param.setSourceRegion(rect); BufferedImage bi = reader.read(0, param); ImageIO.write(bi, suffix, output); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { try { if(fis != null) fis.close(); if(iis != null) iis.close(); } catch (IOException e) { e.printStackTrace(); } } }else { log.warn("the src image is not exist."); } } public void cutImage(File srcImg, OutputStream output, int x, int y, int width, int height){ cutImage(srcImg, output, new java.awt.Rectangle(x, y, width, height)); } public void cutImage(File srcImg, String destImgPath, java.awt.Rectangle rect){ File destImg = new File(destImgPath); if(destImg.exists()){ String p = destImg.getPath(); try { if(!destImg.isDirectory()) p = destImg.getParent(); if(!p.endsWith(File.separator)) p = p + File.separator; cutImage(srcImg, new java.io.FileOutputStream(p + DEFAULT_CUT_PREVFIX + "_" + new java.util.Date().getTime() + "_" + srcImg.getName()), rect); } catch (FileNotFoundException e) { log.warn("the dest image is not exist."); } }else log.warn("the dest image folder is not exist."); } public void cutImage(File srcImg, String destImg, int x, int y, int width, int height){ cutImage(srcImg, destImg, new java.awt.Rectangle(x, y, width, height)); } public void cutImage(String srcImg, String destImg, int x, int y, int width, int height){ cutImage(new File(srcImg), destImg, new java.awt.Rectangle(x, y, width, height)); } /** * <p>Title: thumbnailImage</p> * <p>Description: 根据图片路径生成缩略图 </p> * @param imagePath 原图片路径 * @param w 缩略图宽 * @param h 缩略图高 * @param prevfix 生成缩略图的前缀 * @param force 是否强制按照宽高生成缩略图(如果为false，则生成最佳比例缩略图) */ public void thumbnailImage(File srcImg, OutputStream output, int w, int h, String prevfix, boolean force){ if(srcImg.exists()){ try { // ImageIO 支持的图片类型 : [BMP, bmp, jpg, JPG, wbmp, jpeg, png, PNG, JPEG, WBMP, GIF, gif] String types = Arrays.toString(ImageIO.getReaderFormatNames()).replace("]", ","); String suffix = null; // 获取图片后缀 if(srcImg.getName().indexOf(".") > -1) { suffix = srcImg.getName().substring(srcImg.getName().lastIndexOf(".") + 1); }// 类型和图片后缀全部小写，然后判断后缀是否合法 if(suffix == null || types.toLowerCase().indexOf(suffix.toLowerCase()+",") < 0){ log.error("Sorry, the image suffix is illegal. the standard image suffix is {}." + types); return ; } log.debug("target image's size, width:{}, height:{}.",w,h); Image img = ImageIO.read(srcImg); // 根据原图与要求的缩略图比例，找到最合适的缩略图比例 if(!force){ int width = img.getWidth(null); int height = img.getHeight(null); if((width*1.0)/w < (height*1.0)/h){ if(width > w){ h = Integer.parseInt(new java.text.DecimalFormat("0").format(height * w/(width*1.0))); log.debug("change image's height, width:{}, height:{}.",w,h); } } else { if(height > h){ w = Integer.parseInt(new java.text.DecimalFormat("0").format(width * h/(height*1.0))); log.debug("change image's width, width:{}, height:{}.",w,h); } } } BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB); Graphics g = bi.getGraphics(); g.drawImage(img, 0, 0, w, h, Color.LIGHT_GRAY, null); g.dispose(); // 将图片保存在原目录并加上前缀 ImageIO.write(bi, suffix, output); output.close(); } catch (IOException e) { log.error("generate thumbnail image failed.",e); } }else{ log.warn("the src image is not exist."); } } public void thumbnailImage(File srcImg, int w, int h, String prevfix, boolean force){ String p = srcImg.getAbsolutePath(); try { if(!srcImg.isDirectory()) p = srcImg.getParent(); if(!p.endsWith(File.separator)) p = p + File.separator; thumbnailImage(srcImg, new java.io.FileOutputStream(p + prevfix +srcImg.getName()), w, h, prevfix, force); } catch (FileNotFoundException e) { log.error("the dest image is not exist.",e); } } public void thumbnailImage(String imagePath, int w, int h, String prevfix, boolean force){ File srcImg = new File(imagePath); thumbnailImage(srcImg, w, h, prevfix, force); } public void thumbnailImage(String imagePath, int w, int h, boolean force){ thumbnailImage(imagePath, w, h, DEFAULT_THUMB_PREVFIX, DEFAULT_FORCE); } public void thumbnailImage(String imagePath, int w, int h){ thumbnailImage(imagePath, w, h, DEFAULT_FORCE); } public static void main(String[] args) { new ImageUtil().thumbnailImage("imgs/Tulips.jpg", 150, 100); new ImageUtil().cutImage("imgs/Tulips.jpg","imgs", 250, 70, 300, 400); } }
效果如下：(使用在上传图片时取缩略图和截图的地方，例如，头像截取并缩略)
