如何使用Java在图像上创建水印？我需要将用户输入的文本添加到图像上的提供位置。任何示例代码/建议都会有所帮助。
答案 0 :(得分：9)
在Thumbnailator中，可以使用Caption图片过滤器为现有图片添加文字标题：
// Image to add a text caption to.
BufferedImage originalImage = ...;
// Set up the caption properties
String caption = "Hello World";
Font font = new Font("Monospaced", Font.PLAIN, 14);
Color c = Color.black;
Position position = Positions.CENTER;
int insetPixels = 0;
// Apply caption to the image
Caption filter = new Caption(caption, font, c, position, insetPixels);
BufferedImage captionedImage = filter.apply(originalImage);
在上面的代码中，文字Hello World将以originalImage为中心绘制，使用等宽字体，黑色前景色，14 pt。
或者，如果要将水印图像应用于现有图像，可以使用Watermark图像过滤器：
BufferedImage originalImage = ...;
BufferedImage watermarkImage = ...;
Watermark filter = new Watermark(Positions.CENTER, watermarkImage, 0.5f);
BufferedImage watermarkedImage = filter.apply(originalImage);
以上代码会将watermarkImage叠加在originalImage之上，以不透明度50％为中心。
Thumbnailator将在普通的旧Java SE上运行 - 一个不必安装任何第三方库。 （但是，需要使用Sun Java运行时。）
完全披露：我是Thumbnailator的开发者。
答案 1 :(得分：5)
或者您可以使用GIF4J库http://www.gif4j.com/java-gif4j-pro-gif-image-watermark.htm#gifimagewatermarkapply
答案 2 :(得分：3)
我最近有类似的需求，发现这篇文章非常有用： http://www.codeyouneed.com/java-watermark-image/
水印方法使用ImgScalr在需要时调整水印大小，并支持在图像的底部/顶部放置文本+水印图像。
为了选择正确的位置，它使用简单的ENUM
public enum PlacementPosition {
TOPLEFT, TOPCENTER, TOPRIGHT, MIDDLELEFT, MIDDLECENTER, MIDDLERIGHT, BOTTOMLEFT, BOTTOMCENTER, BOTTOMRIGHT
}
整个水印逻辑就是这个方法：
/**
* Generate a watermarked image.
*
* @param originalImage
* @param watermarkImage
* @param position
* @param watermarkSizeMaxPercentage
* @return image with watermark
* @throws IOException
*/
public static BufferedImage watermark(BufferedImage originalImage,
BufferedImage watermarkImage, PlacementPosition position,
double watermarkSizeMaxPercentage) throws IOException {
int imageWidth = originalImage.getWidth();
int imageHeight = originalImage.getHeight();
int watermarkWidth = getWatermarkWidth(originalImage, watermarkImage,
watermarkSizeMaxPercentage);
int watermarkHeight = getWatermarkHeight(originalImage, watermarkImage,
watermarkSizeMaxPercentage);
// We create a new image because we want to keep the originalImage
// object intact and not modify it.
BufferedImage bufferedImage = new BufferedImage(imageWidth,
imageHeight, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = (Graphics2D) bufferedImage.getGraphics();
g2d.drawImage(originalImage, 0, 0, null);
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int x = 0;
int y = 0;
if (position != null) {
switch (position) {
case TOPLEFT:
x = 0;
y = 0;
break;
case TOPCENTER:
x = (imageWidth / 2) - (watermarkWidth / 2);
y = 0;
break;
case TOPRIGHT:
x = imageWidth - watermarkWidth;
y = 0;
break;
case MIDDLELEFT:
x = 0;
y = (imageHeight / 2) - (watermarkHeight / 2);
break;
case MIDDLECENTER:
x = (imageWidth / 2) - (watermarkWidth / 2);
y = (imageHeight / 2) - (watermarkHeight / 2);
break;
case MIDDLERIGHT:
x = imageWidth - watermarkWidth;
y = (imageHeight / 2) - (watermarkHeight / 2);
break;
case BOTTOMLEFT:
x = 0;
y = imageHeight - watermarkHeight;
break;
case BOTTOMCENTER:
x = (imageWidth / 2) - (watermarkWidth / 2);
y = imageHeight - watermarkHeight;
break;
case BOTTOMRIGHT:
x = imageWidth - watermarkWidth;
y = imageHeight - watermarkHeight;
break;
default:
break;
}
}
g2d.drawImage(Scalr.resize(watermarkImage, Method.ULTRA_QUALITY,
watermarkWidth, watermarkHeight), x, y, null);
return bufferedImage;
}
计算水印大小的相应方法是：
/**
*
* @param originalImage
* @param watermarkImage
* @param maxPercentage
* @return
*/
private static Pair<Double, Double> calculateWatermarkDimensions(
BufferedImage originalImage, BufferedImage watermarkImage,
double maxPercentage) {
double imageWidth = originalImage.getWidth();
double imageHeight = originalImage.getHeight();
double maxWatermarkWidth = imageWidth / 100.0 * maxPercentage;
double maxWatermarkHeight = imageHeight / 100.0 * maxPercentage;
double watermarkWidth = watermarkImage.getWidth();
double watermarkHeight = watermarkImage.getHeight();
if (watermarkWidth > maxWatermarkWidth) {
double aspectRatio = watermarkWidth / watermarkHeight;
watermarkWidth = maxWatermarkWidth;
watermarkHeight = watermarkWidth / aspectRatio;
}
if (watermarkHeight > maxWatermarkHeight) {
double aspectRatio = watermarkWidth / watermarkHeight;
watermarkHeight = maxWatermarkHeight;
watermarkWidth = watermarkHeight / aspectRatio;
}
return Pair.of(watermarkWidth, watermarkHeight);
}
/**
*
* @param originalImage
* @param watermarkImage
* @param maxPercentage
* @return
*/
public static int getWatermarkWidth(BufferedImage originalImage,
BufferedImage watermarkImage, double maxPercentage) {
return calculateWatermarkDimensions(originalImage, watermarkImage,
maxPercentage).getLeft().intValue();
}
/**
*
* @param originalImage
* @param watermarkImage
* @param maxPercentage
* @return
*/
public static int getWatermarkHeight(BufferedImage originalImage,
BufferedImage watermarkImage, double maxPercentage) {
return calculateWatermarkDimensions(originalImage, watermarkImage,
maxPercentage).getRight().intValue();
}
再次，http://www.codeyouneed.com/java-watermark-image/获得一个很好的样本的所有学分。
答案 3 :(得分：1)
我用于我的项目IM4Java library - 用于java的imagemagick包装器。有关水印示例，请参阅http://www.imagemagick.org/Usage/annotating/
答案 4 :(得分：1)
使用此代码，它的工作原理.. 这里，图像用作水印并放置在位置10,10
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class WatermarkImage {
public static void addWatermark(String localImagePath) {
try {
BufferedImage image = ImageIO.read(new File(localImagePath));
BufferedImage overlay = ImageIO.read(new File(".\\data\\watermark\\watermark.png"));
// create the new image, canvas size is the max. of both image sizes
int w = Math.max(image.getWidth(), overlay.getWidth());
int h = Math.max(image.getHeight(), overlay.getHeight());
BufferedImage combined = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
// paint both images, preserving the alpha channels
Graphics g = combined.getGraphics();
g.drawImage(image, 0, 0, null);
g.drawImage(overlay, 10, 0, null);
ImageIO.write(combined, "PNG", new File(localImagePath));
} catch (IOException e) {
e.printStackTrace();
}
}
}
答案 5 :(得分：1)
以下是在任何图片上添加水印的代码
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
public class WatermarkImage {
public static void main(String[] args) {
File origFile = new File("C:/OrignalImage.jpg");
ImageIcon icon = new ImageIcon(origFile.getPath());
// create BufferedImage object of same width and height as of original image
BufferedImage bufferedImage = new BufferedImage(icon.getIconWidth(),
icon.getIconHeight(), BufferedImage.TYPE_INT_RGB);
// create graphics object and add original image to it
Graphics graphics = bufferedImage.getGraphics();
graphics.drawImage(icon.getImage(), 0, 0, null);
// set font for the watermark text
graphics.setFont(new Font("Arial", Font.BOLD, 30));
//unicode characters for (c) is \u00a9
String watermark = "\u00a9 JavaXp.com";
// add the watermark text
graphics.drawString(watermark, 0, icon.getIconHeight() / 2);
graphics.dispose();
File newFile = new File("C:/WatermarkedImage.jpg");
try {
ImageIO.write(bufferedImage, "jpg", newFile);
} catch (IOException e) {
e.printStackTrace();
}
System.out.println(newFile.getPath() + " created successfully!");
}
}
答案 6 :(得分：0)
首先使用
在Windows中的C：\ Imagemagick文件夹中输入Imagemagickhttp://www.imagemagick.org/download/binaries/ImageMagick-6.8.8-7-Q16-x86-dll.exe
安装时添加C：\ ImageMagick;在PATH环境变量中
并使用以下代码
package UploadServlet;
import java.io.*;
import java.util.*;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.output.*;
/**
* Servlet implementation class UploadServlet
*/
public class UploadServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
private boolean isMultipart;
private String filePath;
private int maxFileSize = 50 * 1024;
private int maxMemSize = 4 * 1024;
private File file ;
public UploadServlet() {
super();
// TODO Auto-generated constructor stub
}
public void init(){
// Get the file location where it would be stored.
filePath = getServletContext().getInitParameter("file-upload");
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
throw new ServletException("GET method used with " +
getClass( ).getName( )+": POST method required.");
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
// Check that we have a file upload request
isMultipart = ServletFileUpload.isMultipartContent(request);
response.setContentType("text/html");
java.io.PrintWriter out = response.getWriter( );
if( !isMultipart ){
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet upload</title>");
out.println("</head>");
out.println("<body>");
out.println("<p>No file uploaded</p>");
out.println("</body>");
out.println("</html>");
return;
}
DiskFileItemFactory factory = new DiskFileItemFactory();
// maximum size that will be stored in memory
factory.setSizeThreshold(maxMemSize);
// Location to save data that is larger than maxMemSize.
factory.setRepository(new File("c:\\temp"));
// Create a new file upload handler
ServletFileUpload upload = new ServletFileUpload(factory);
// maximum file size to be uploaded.
upload.setSizeMax( maxFileSize );
try{
// Parse the request to get file items.
List fileItems = upload.parseRequest(request);
// Process the uploaded file items
Iterator i = fileItems.iterator();
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet upload</title>");
out.println("</head>");
out.println("<body>");
out.println("<h3>Watermark :</h3>");
out.println("Select a file to upload: <br />");
out.println("<form action=\"UploadServlet\" method=\"post\" enctype=\"multipart/form-data\">");
out.println("<input type=\"file\" name=\"file\" size=\"50\" /><br/>");
out.println("<input type=\"submit\" value=\"Upload File\" />");
out.println("</form><br/>");
while ( i.hasNext () )
{
FileItem fi = (FileItem)i.next();
if ( !fi.isFormField () )
{
// Get the uploaded file parameters
String fieldName = fi.getFieldName();
String fileName = fi.getName();
//System.out.println("Filename:" + fileName);
String contentType = fi.getContentType();
boolean isInMemory = fi.isInMemory();
long sizeInBytes = fi.getSize();
// get application path
String webAppPath = getServletContext().getRealPath("/");
//System.out.println("Web Application Path :" + webAppPath);
// Write the file
file = new File( webAppPath + "ImageTest.jpeg") ;
fi.write( file ) ;
out.println("<br/><h3>Uploaded File :</h3><img src=\"ImageTest.jpeg\" height='300px' width='300px' />");
String command = "";
command = "convert.exe -draw \"gravity south fill black text 0,0 'Watermark' \" \"" + webAppPath + "ImageTest.jpeg \" \""+ webAppPath +"imageTest_result.jpg \"";
ProcessBuilder pb = new ProcessBuilder("cmd.exe", "/c", command);
Process p = pb.start();
try {
Thread.sleep(1000);
} catch(InterruptedException ex) {
Thread.currentThread().interrupt();
}
out.println("<br/><h3>Watermarked File :</h3><img src=\"imageTest_result.jpg\" height='300px' width='300px' />");
}
}
out.println("</body>");
out.println("</html>");
}catch(Exception ex) {
System.out.println(ex);
out.println("<br/><font color='red'><b>"+ex.getMessage()+"</b></font><br/>");
}
}
}