Java 在图片上写文字和图片

写文字之前.png
写文字之后.png

import com.sun.image.codec.jpeg.ImageFormatException;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageDecoder;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

import javax.imageio.ImageIO;
import javax.swing.;
import java.awt.;
import java.awt.font.FontRenderContext;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.*;

public class MainIn {

static String picturePath;
static String pictureInName = "/bg.jpeg";
static String pictureOutName = "/bg_out.jpeg";


public static void main(String[] args) {
    String _dir = System.getProperty("user.dir");
    picturePath = _dir + File.separator + "src" + File.separator;

// exportImg1();
drawTextToPicture("我好,中国", picturePath + "/head_img.png");
}

///在图片上画文字
public static void drawTextToPicture(String username, String headImg) {
    try {
        //1.jpg是你的 主图片的路径
        InputStream is = new FileInputStream(picturePath + pictureInName);


        //通过JPEG图象流创建JPEG数据流解码器
        JPEGImageDecoder jpegDecoder = JPEGCodec.createJPEGDecoder(is);
        //解码当前JPEG数据流，返回BufferedImage对象
        BufferedImage buffImg = jpegDecoder.decodeAsBufferedImage();
        //得到画笔对象
        Graphics g = buffImg.getGraphics();

        //创建你要附加的图象。
        //小图片的路径
        ImageIcon imgIcon = new ImageIcon(headImg);

        //得到Image对象。
        Image img = imgIcon.getImage();

        //将小图片绘到大图片上。
        //5,300 .表示你的小图片在大图片上的位置。
        g.drawImage(img, 400, 15, null);

        //设置颜色。
        g.setColor(Color.BLACK);


        //最后一个参数用来设置字体的大小
        Font f = new Font("宋体", Font.PLAIN, 25);
        Color mycolor = Color.red;//new Color(0, 0, 255);
        g.setColor(mycolor);
        g.setFont(f);

        //10,20 表示这段文字在图片上的位置(x,y) .第一个是你设置的内容。
        g.drawString(username, 100, 135);

        g.dispose();
        OutputStream os;

        os = new FileOutputStream(picturePath + pictureOutName);
        //创键编码器，用于编码内存中的图象数据。
        JPEGImageEncoder en = JPEGCodec.createJPEGEncoder(os);
        en.encode(buffImg);

        is.close();
        os.close();
    } catch (ImageFormatException | IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

///创建一个文本画布
public static void createTextCanvas() {
    int width = 100;
    int height = 100;
    String s = "你好";

    File file = new File(picturePath + pictureInName);
    Font font = new Font("Serif", Font.BOLD, 10);
    BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    Graphics2D g2 = (Graphics2D) bi.getGraphics();
    g2.setBackground(Color.WHITE);
    g2.clearRect(0, 0, width, height);
    g2.setPaint(Color.RED);

    FontRenderContext context = g2.getFontRenderContext();
    Rectangle2D bounds = font.getStringBounds(s, context);
    double x = (width - bounds.getWidth()) / 2;
    double y = (height - bounds.getHeight()) / 2;
    double ascent = -bounds.getY();
    double baseY = y + ascent;

    g2.drawString(s, (int) x, (int) baseY);

    try {
        ImageIO.write(bi, "jpg", file);
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

}

2021年01月15日13:29:09更新
 文字增加抗锯齿, 文本x  y 坐标校准
~~~



    ///在图片上画文字
    public static void drawTextToPicture(List<DetailCoordinate> _detailList) {
        try {

            BufferedImage _mainImage = getImage(picturePath + pictureInName);
            SunGraphics2D g = (SunGraphics2D) _mainImage.getGraphics();

            g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_LCD_HRGB);

            OutputStream os = new FileOutputStream(picturePath + pictureOutName);
            for (DetailCoordinate itemCoordinate : _detailList) {
                if (itemCoordinate.type == 0) {
                    //最后一个参数用来设置字体的大小
                    Font f = new Font(Font.SERIF, Font.PLAIN, itemCoordinate.size);
                    Color myColor = fromStrToARGB(itemCoordinate.getColor());//new Color(0, 0, 255);
                    g.setColor(myColor);
                    g.setFont(f);

                    FontMetrics fm = g.getFontMetrics();
                    g.drawString(itemCoordinate.txt, itemCoordinate.x, fm.getMaxAscent() + itemCoordinate.y);
                } else if (itemCoordinate.type == 1) {
                    //创建你要附加的图象。
                    //小图片的路径
                    ImageIcon imgIcon = new ImageIcon(itemCoordinate.txt);

                    //得到Image对象。
                    Image img = imgIcon.getImage();

                    //将小图片绘到大图片上。
                    //5,300 .表示你的小图片在大图片上的位置。
                    g.drawImage(img, itemCoordinate.x, itemCoordinate.y, null);

                    //设置颜色。
                    g.setColor(Color.BLACK);
                }
            }
            g.dispose();
            _mainImage.flush();

            ImageIO.write(_mainImage, "png", os);
        } catch (ImageFormatException | IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }