java给图片添加图片水印,设置样式平铺,拉伸
import javax.imageio.ImageIO; import java.awt.*; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; public class ImageUtil { /** * 给图片添加水印 * @param originImgPath 原始图片的路径 * @param targetImgPath 添加水印后图片的保存路径 * @param markImgPath 水印的路径 * @param mode 内部枚举类,用于指定水印铺设的样式,平铺,拉伸等 * @param margin_x 水印之间的水平间距 * @param margin_y 水印之间的垂直间距 * @param opacity 水印透明度 * @param markAngle 水印旋转角度,应在正负45度之间 * @throws IOException */ public static void markImage(String originImgPath,String targetImgPath,String markImgPath,int mode,int margin_x,int margin_y,float opacity,double markAngle) throws IOException { if(markAngle>45||markAngle<-45){ throw new RuntimeException("旋转角度必须在正负45度之间。"); } BufferedImage originImg= ImageIO.read(new File(originImgPath)); BufferedImage markImage = ImageIO.read(new File(markImgPath)); Graphics2D graphics = (Graphics2D) originImg.getGraphics(); graphics.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, opacity)); graphics.rotate(markAngle); if(mode == PAINT_MODE.TILED.mode){ int canvasHeight = originImg.getHeight(); int canvasWidth = originImg.getWidth(); int markHeight = markImage.getHeight(); int markWidth = markImage.getHeight(); int interval = markWidth+markHeight; for(int i=-canvasHeight;i<canvasWidth+canvasHeight;i=i+interval+margin_x){ for(int j=-canvasWidth;j<canvasHeight+canvasWidth;j=j+interval+margin_y){ graphics.drawImage(markImage,i,j,markImage.getWidth(),markImage.getHeight(),null); } } } graphics.dispose(); ImageIO.write(originImg,"png",new File(targetImgPath)); } //内部枚举类 enum PAINT_MODE{ REGULAR(0),//常规 TILED(1),//平铺 STRETCHED(2);//拉伸 private int mode; PAINT_MODE(int mode){ this.mode = mode; } } //测试main方法 public static void main(String[] args) { try { markImage("D:/source.png","D:/target.png","D:/mark.png",PAINT_MODE.TILED.mode,50,50,0.5f,-45); } catch (IOException e) { e.printStackTrace(); } } }
效果图:
issue:1.只贴了平铺样式,拉伸只需要将水印图片的长宽设置为和源图片一样大。常规样式只需不循环遍历即可。
2.旋转有一定的空间浪费,我本想通过三角函数计算旋转特定角度后循环的起止X,y轴位置,但是计算结果应用后并不能达到预期效果,只好给一个较大的定值。
3.添加文字水印更为简单,只需调用graphics2D的drawString方法,并设置字体和颜色即可。希望有需求的朋友多多动手。