Java實現圖片壓縮【轉載】
阿新 • • 發佈:2019-02-07
今天無意中發現這篇文章,可以幫助實現圖片壓縮,以後有限定圖片大小的就可以自己實現了。
文章來源:http://blog.csdn.net/javafay/article/details/8031620【點滴而為知】package com.bonc.ioc.lmp.common.util; import java.awt.Graphics2D; import java.awt.Rectangle; 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.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import javax.imageio.ImageIO; import org.junit.Test; /** * 圖片工具類,完成圖片的擷取 * 所有方法返回值均未boolean型 */ public class ImageHelper { /** * 實現影象的等比縮放 * @param source * @param targetW * @param targetH * @return */ private static BufferedImage resize(BufferedImage source, int targetW, int targetH) { // targetW,targetH分別表示目標長和寬 int type = source.getType(); BufferedImage target = null; double sx = (double) targetW / source.getWidth(); double sy = (double) targetH / source.getHeight(); // 這裡想實現在targetW,targetH範圍內實現等比縮放。如果不需要等比縮放 // 則將下面的if else語句註釋即可 if (sx < sy) { sx = sy; targetW = (int) (sx * source.getWidth()); } else { sy = sx; targetH = (int) (sy * source.getHeight()); } if (type == BufferedImage.TYPE_CUSTOM) { // handmade 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(); // smoother than exlax: g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC); g.drawRenderedImage(source, AffineTransform.getScaleInstance(sx, sy)); g.dispose(); return target; } /** * 實現影象的等比縮放和縮放後的擷取, 處理成功返回true, 否則返回false * @param inFilePath 要擷取檔案的路徑 * @param outFilePath 擷取後輸出的路徑 * @param width 要擷取寬度 * @param hight 要擷取的高度 * @throws Exception */ public static boolean compress(String inFilePath, String outFilePath, int width, int hight) { boolean ret = false; File file = new File(inFilePath); File saveFile = new File(outFilePath); InputStream in = null; try { in = new FileInputStream(file); ret = compress(in, saveFile, width, hight); } catch (FileNotFoundException e) { e.printStackTrace(); ret = false; } finally{ if(null != in){ try { in.close(); } catch (IOException e) { e.printStackTrace(); } } } return ret; } /** * 實現影象的等比縮放和縮放後的擷取, 處理成功返回true, 否則返回false * @param in 要擷取檔案流 * @param outFilePath 擷取後輸出的路徑 * @param width 要擷取寬度 * @param hight 要擷取的高度 * @throws Exception */ public static boolean compress(InputStream in, File saveFile, int width, int hight) { // boolean ret = false; BufferedImage srcImage = null; try { srcImage = ImageIO.read(in); } catch (IOException e) { e.printStackTrace(); return false; } if (width > 0 || hight > 0) { // 原圖的大小 int sw = srcImage.getWidth(); int sh = srcImage.getHeight(); // 如果原影象的大小小於要縮放的影象大小,直接將要縮放的影象複製過去 if (sw > width && sh > hight) { srcImage = resize(srcImage, width, hight); } else { String fileName = saveFile.getName(); String formatName = fileName.substring(fileName .lastIndexOf('.') + 1); try { ImageIO.write(srcImage, formatName, saveFile); } catch (IOException e) { e.printStackTrace(); return false; } return true; } } // 縮放後的影象的寬和高 int w = srcImage.getWidth(); int h = srcImage.getHeight(); // 如果縮放後的影象和要求的影象寬度一樣,就對縮放的影象的高度進行擷取 if (w == width) { // 計算X軸座標 int x = 0; int y = h / 2 - hight / 2; try { saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile); } catch (IOException e) { e.printStackTrace(); return false; } } // 否則如果是縮放後的影象的高度和要求的影象高度一樣,就對縮放後的影象的寬度進行擷取 else if (h == hight) { // 計算X軸座標 int x = w / 2 - width / 2; int y = 0; try { saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile); } catch (IOException e) { e.printStackTrace(); return false; } } return true; } /** * 實現影象的等比縮放和縮放後的擷取, 處理成功返回true, 否則返回false * @param in 圖片輸入流 * @param saveFile 壓縮後的圖片輸出流 * @param proportion 壓縮比 * @throws Exception */ public static boolean compress(InputStream in, File saveFile, int proportion) { if(null == in ||null == saveFile ||proportion < 1){// 檢查引數有效性 //LoggerUtil.error(ImageHelper.class, "--invalid parameter, do nothing!"); return false; } BufferedImage srcImage = null; try { srcImage = ImageIO.read(in); } catch (IOException e) { e.printStackTrace(); return false; } // 原圖的大小 int width = srcImage.getWidth() / proportion; int hight = srcImage.getHeight() / proportion; srcImage = resize(srcImage, width, hight); // 縮放後的影象的寬和高 int w = srcImage.getWidth(); int h = srcImage.getHeight(); // 如果縮放後的影象和要求的影象寬度一樣,就對縮放的影象的高度進行擷取 if (w == width) { // 計算X軸座標 int x = 0; int y = h / 2 - hight / 2; try { saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile); } catch (IOException e) { e.printStackTrace(); return false; } } // 否則如果是縮放後的影象的高度和要求的影象高度一樣,就對縮放後的影象的寬度進行擷取 else if (h == hight) { // 計算X軸座標 int x = w / 2 - width / 2; int y = 0; try { saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile); } catch (IOException e) { e.printStackTrace(); return false; } } return true; } /** * 實現縮放後的截圖 * @param image 縮放後的影象 * @param subImageBounds 要擷取的子圖的範圍 * @param subImageFile 要儲存的檔案 * @throws IOException */ private static void saveSubImage(BufferedImage image, Rectangle subImageBounds, File subImageFile) throws IOException { if (subImageBounds.x < 0 || subImageBounds.y < 0 || subImageBounds.width - subImageBounds.x > image.getWidth() || subImageBounds.height - subImageBounds.y > image.getHeight()) { //LoggerUtil.error(ImageHelper.class, "Bad subimage bounds"); return; } BufferedImage subImage = image.getSubimage(subImageBounds.x,subImageBounds.y, subImageBounds.width, subImageBounds.height); String fileName = subImageFile.getName(); String formatName = fileName.substring(fileName.lastIndexOf('.') + 1); ImageIO.write(subImage, formatName, subImageFile); } @Test public static void main(String[] args) throws Exception { /** * saveSubImage 截圖類的使用 * srcImage 為BufferedImage物件 * Rectangle 為需要截圖的長方形座標 * saveFile 需要儲存的路徑及名稱 * **/ //需要截圖的長方形座標 /*Rectangle rect =new Rectangle(); rect.x=40; rect.y=40; rect.height=160; rect.width=160; InputStream in = null; //需要儲存的路徑及名稱 File saveFile = new File("d:\\ioc\\files\\aaa2.jpg"); //需要進行處理的圖片的路徑 in = new FileInputStream(new File("d:\\ioc\\files\\aaa.jpg")); BufferedImage srcImage = null; //將輸入的資料轉為BufferedImage物件 srcImage = ImageIO.read(in); ImageHelper img=new ImageHelper(); img.saveSubImage(srcImage, rect, saveFile);*/ /** * compress 圖片縮放類的使用(縮圖) * srcImage 為InputStream物件 * Rectangle 為需要截圖的長方形座標 * proportion 為壓縮比例 * **/ InputStream in = null; //縮放後需要儲存的路徑 File saveFile = new File("d:\\ioc\\files\\aaa2.jpg"); try { //原圖片的路徑 in = new FileInputStream(new File("d:\\ioc\\files\\aaa.jpg")); if(compress(in, saveFile, 10)){ System.out.println("圖片壓縮十倍!"); } } catch (Exception e) { e.printStackTrace(); } finally { in.close(); } } }