1.向PDF中添加圖片
PdfReader reader = new PdfReader(infilePath);//選擇需要印章的pdf
PdfStamper stamp=new PdfStamper(reader,new FileOutputStream(outFilePath));//加完印章後的pdf
over = stamp.getOverContent(n);//設置在第幾頁打印印章
over.addImage(img);
2.縮放圖片(PNG)
方式1:這個方式可以縮放圖片但是,如果圖片是透明的,則圖片縮放後背景顏色變成黑色
先使用Image讀取到圖片,再使用BufferedImage操作圖片,這是Image的一個實現類。
java.awt.Image image = ImageIO.read(new File(imgPath));
BufferedImage img = new BufferedImage(120,120, BufferedImage.TYPE_INT_RGB);
//縮小
img.getGraphics().drawImage(image.getScaledInstance(120, 120, image.SCALE_AREA_AVERAGING), 0, 0, null);
方式2:避免的透明圖片背景變黑
BufferedImage img = ImageIO.read(new File(imgPath));
BufferedImage to = new BufferedImage(120, 120, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = to.createGraphics();
to = g2d.getDeviceConfiguration().createCompatibleImage(120, 120,
Transparency.TRANSLUCENT);
g2d.dispose();
g2d = to.createGraphics();
@SuppressWarnings("static-access")
java.awt.Image from = img.getScaledInstance(120, 120, img.SCALE_AREA_AVERAGING);
g2d.drawImage(from, 0, 0, null);
g2d.dispose();
3.透明圖片背景變黑
可以使用方式2