JAVA生成圖片縮圖、JAVA擷取圖片區域性內容
阿新 • • 發佈：2018-11-05
目前，google已經有了更好的處理JAVA圖片的工具，請搜尋：Thumbnailator
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原生態類生成圖片縮圖和裁剪圖片 </p> * <p>Email:[email protected] </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: 根據圖片路徑生成縮圖 </p> * @param imagePath 原圖片路徑 * @param w 縮圖寬 * @param h 縮圖高 * @param prevfix 生成縮圖的字首 * @param force 是否強制按照寬高生成縮圖(如果為false，則生成最佳比例縮圖) */ public void thumbnailImage(File imgFile, int w, int h, String prevfix, boolean force){ if(imgFile.exists()){ try { // ImageIO 支援的圖片型別 : [BMP, bmp, jpg, JPG, wbmp, jpeg, png, PNG, JPEG, WBMP, GIF, gif] String types = Arrays.toString(ImageIO.getReaderFormatNames()); String suffix = null; // 獲取圖片字尾 if(imgFile.getName().indexOf(".") > -1) { suffix = imgFile.getName().substring(imgFile.getName().lastIndexOf(".") + 1); }// 型別和圖片字尾全部小寫，然後判斷後綴是否合法 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){ // 根據原圖與要求的縮圖比例，找到最合適的縮圖比例 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(); // 將圖片儲存在原目錄並加上字首 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：（原圖是電腦"圖片"資料夾下的鬱金香圖片，大小1024*768，生成的圖片為200*150大小，保持4:3的比例）
JAVA 擷取圖片區域性內容：
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.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:[email protected] </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: 根據原圖與裁切size擷取區域性圖片</p> * @param srcImg 源圖片 * @param output 圖片輸出流 * @param rect 需要擷取部分的座標和大小 */ 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 支援的圖片型別 : [BMP, bmp, jpg, JPG, wbmp, jpeg, png, PNG, JPEG, WBMP, GIF, gif] String types = Arrays.toString(ImageIO.getReaderFormatNames()).replace("]", ","); String suffix = null; // 獲取圖片字尾 if(srcImg.getName().indexOf(".") > -1) { suffix = srcImg.getName().substring(srcImg.getName().lastIndexOf(".") + 1); }// 型別和圖片字尾全部小寫，然後判斷後綴是否合法 if(suffix == null || types.toLowerCase().indexOf(suffix.toLowerCase()+",") < 0){ log.error("Sorry, the image suffix is illegal. the standard image suffix is {}." + types); return ; } // 將FileInputStream 轉換為ImageInputStream iis = ImageIO.createImageInputStream(fis); // 根據圖片型別獲取該種類型的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: 根據圖片路徑生成縮圖 </p> * @param imagePath 原圖片路徑 * @param w 縮圖寬 * @param h 縮圖高 * @param prevfix 生成縮圖的字首 * @param force 是否強制按照寬高生成縮圖(如果為false，則生成最佳比例縮圖) */ public void thumbnailImage(File srcImg, OutputStream output, int w, int h, String prevfix, boolean force){ if(srcImg.exists()){ try { // ImageIO 支援的圖片型別 : [BMP, bmp, jpg, JPG, wbmp, jpeg, png, PNG, JPEG, WBMP, GIF, gif] String types = Arrays.toString(ImageIO.getReaderFormatNames()).replace("]", ","); String suffix = null; // 獲取圖片字尾 if(srcImg.getName().indexOf(".") > -1) { suffix = srcImg.getName().substring(srcImg.getName().lastIndexOf(".") + 1); }// 型別和圖片字尾全部小寫，然後判斷後綴是否合法 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); // 根據原圖與要求的縮圖比例，找到最合適的縮圖比例 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(); // 將圖片儲存在原目錄並加上字首 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：(使用在上傳圖片時取縮圖和截圖的地方，例如，影象擷取並縮略)
