图片不变形缩放裁剪
最近做一个项目用到图片的上传操作，怎么实现图片的上传缩放裁剪后图片不变形。例如将图片经过处理后变成统一的高宽比例而图片不变形。请各位高手指教。
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比例缩小，不足部分补上透明像素，最简单的办法！
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使用drawimage将图片缩放裁剪到合适比例 在使用imagewriter将图片保存到本地就行了 或者保存到服务器
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明天上班给你发代码，各种变形、剪裁！mark了
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求共享，学习了
package com.bean.tuil;import java.awt.AlphaComposite;import java.awt.Color;import java.awt.Font;import java.awt.Graphics2D;import java.awt.Image;import java.awt.geom.AffineTransform;import java.awt.image.AffineTransformOp;import java.awt.image.BufferedImage;import java.io.File;import java.io.IOException;import java.net.MalformedURLException;import java.net.URL;import java.util.Date;import javax.imageio.ImageIO;/** * 对图片的操作 * * @author yangyz * */public class ImageControl { // 添加字体的属性值 private Font font = new Font("", Font.PLAIN, 12); private Graphics2D g = null; private int fontsize = 0; private int x = 0; private int y = 0; private String destDir = "F:\\"; public void setDestDir(String path) { this.destDir = path; // 目录不存在 File file = new File(path); if (!file.exists()) { file.mkdir(); } } /** * 导入本地图片到缓冲中 * * @param imgPath * @return */ public BufferedImage loadImageLocal(String imgPath) { try { return ImageIO.read(new File(imgPath)); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); return null; } } /** * 读取网络中的图片到缓冲 * * @param imgPath * @return */ public BufferedImage loadImageUrl(String imgPath) { URL url; try { url = new URL(imgPath); return ImageIO.read(url); } catch (MalformedURLException e) { // TODO Auto-generated catch block e.printStackTrace(); return null; } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); return null; } } /** * 生成新图片到本地 * * @param newImage * 新名字 * @param img * 缓冲 * @param type * 类别 */ public void writeImageLocal(BufferedImage img, String type) { if (img != null) { File outputFile = new File(this.destDir + new Date().getTime() + "." + type); try { ImageIO.write(img, type, outputFile); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } /** * 设置文字字体，大小 * * @param fontStyle * @param fontSize */ public void setFont(String fontStyle, int fontSize) { this.fontsize = fontSize; this.font = new Font(fontStyle, Font.PLAIN, fontSize); } /** * 单行文本 * * @param img * @param content * @param x * @param y * @return */ public BufferedImage modifyImage(BufferedImage img, Object content) { try { int w = img.getWidth(); int h = img.getHeight(); g = img.createGraphics(); g.setColor(Color.RED); if (this.font != null) { g.setFont(this.font); } // 文字输出位置 this.y = h - fontsize - 10; this.x = w - 70; if (content != null) { g.drawString(content.toString(), this.x, this.y); } g.dispose(); } catch (Exception e) { e.printStackTrace(); } return img; } /** * 将两张图片合并 * * @param base * @param dest * 目标 * @return */ public BufferedImage modifyImageTogether(BufferedImage base, BufferedImage dest) { try { int w = base.getWidth(); int h = base.getHeight(); int dw = dest.getWidth(); int dh = dest.getHeight(); g = dest.createGraphics(); AlphaComposite cp = AlphaComposite.getInstance( AlphaComposite.SRC_OVER, 0.3f); g.setComposite(cp); g.drawImage(base, dw - w, dh - h, w, h, null); g.dispose(); } catch (Exception e) { e.printStackTrace(); } return dest; } /** * 改变图片大小 * * @param img * @param weight * @param height * @return */ public BufferedImage modifySize(BufferedImage img, int width, int height) { try { int w = img.getWidth(); int h = img.getHeight(); double wRation = (new Integer(width)).doubleValue() / w; double hRation = (new Integer(height)).doubleValue() / h; Image image = img.getScaledInstance(width, height, Image.SCALE_SMOOTH); AffineTransformOp op = new AffineTransformOp(AffineTransform .getScaleInstance(wRation, hRation), null); image = op.filter(img, null); img = (BufferedImage) image; } catch (Exception e) { e.printStackTrace(); } return img; } public BufferedImage changeSize(BufferedImage img, int width, int height) { try { BufferedImage distin = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); g = distin.createGraphics(); g.drawImage(img, 0, 0, width, height, null); return distin; } catch (Exception e) { e.printStackTrace(); return null; } } /** * 截图 * * @param img * @param x * @param y * @param width * @param height * @return */ public BufferedImage cutImage(BufferedImage img, int x, int y, int width, int height) { BufferedImage distin = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); try { g = distin.createGraphics(); // 原图的大小，以及截图的坐标及大小 g.drawImage(img, 0, 0, width, height, x, y, width, height, null); } catch (Exception e) { e.printStackTrace(); } return distin; } /** * 测试 * * @param args */ public static void main(String[] args) { ImageControl ic = new ImageControl(); // 两张图片合并 BufferedImage d = ic .loadImageLocal("C:\\Documents and Settings\\yangyz\\Desktop\\MyAPP\\catergory_list_right.jpg"); BufferedImage b = ic .loadImageLocal("C:\\Documents and Settings\\yangyz\\Desktop\\MyAPP\\ico_exPlore_home_sports_bundles_selected.png"); ic.setDestDir("f:\\temp\\"); ic.writeImageLocal(ic.modifyImageTogether(b, d), "jpg"); // 在向生成的图片添加文字 ic.modifyImage(d, "Troy Young"); // // 根据坐标截图 // BufferedImage d = ic // .loadImageLocal("C:\\Documents and Settings\\yangyz\\Desktop\\MyAPP\\catergory_list_right.jpg"); // ic.setDestDir("f:\\temp\\"); ic.writeImageLocal(ic.cutImage(d, 30, 20, 200, 100), "jpg"); // 修改图片大小 // BufferedImage d = ic // .loadImageLocal("C:\\Documents and Settings\\yangyz\\Desktop\\MyAPP\\catergory_list_right.jpg"); // ic.setDestDir("f:\\temp\\"); ic.writeImageLocal(ic.modifySize(d, 210, 175), "jpg"); System.out.println("成功"); }}