Java图片处理（二）图片加水印

图片加水印，是通过图片重叠绘制实现的。实现代码如下：

public static void press(String pressImg, String pressText, String targetImg,

String fontName, int fontStyle, int color, int fontSize, int x, int y) {

try {

File _file = new File(targetImg);

Image src = ImageIO.read(_file);

int wideth = src.getWidth(null);

int height = src.getHeight(null);

BufferedImage image = new BufferedImage(wideth, height,

BufferedImage.TYPE_INT_RGB);

Graphics2D g = image.createGraphics();

g.drawImage(src, 0, 0, wideth, height, null);

g.setColor(new Color(255, 255, 255, 80));

g.setFont(new Font(fontName, fontStyle, fontSize));

g.drawString(pressText, wideth - fontSize - x, height - fontSize / 2 - y);

//水印文件

File _filebiao = new File(pressImg);

Image src_biao = ImageIO.read(_filebiao);

int wideth_biao = src_biao.getWidth(null);

int height_biao = src_biao.getHeight(null);

g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 0.4f));

g.drawImage(src_biao, (wideth - wideth_biao) / 2,

height - fontSize / 2 - 50, wideth_biao/2-10, height_biao/2-10, null);

g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));

g.dispose();

FileOutputStream out = new FileOutputStream(targetImg);

JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

encoder.encode(image);

out.close();

} catch (Exception e) {

System.out.println(e);

}

}

图片设置透明度

g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 0.4f));

g.drawImage(src_biao, (wideth - wideth_biao) / 2,

height - fontSize / 2 - 50, wideth_biao/2-10, height_biao/2-10, null);

g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));

文字设置透明度

文字的透明度由颜色决定，因此只需要设置颜色的RGBA即可。如下：

Graphics2D g = image.createGraphics();

g.drawImage(src, 0, 0, wideth, height, null);

g.setColor(new Color(255, 255, 255, 80));

g.setFont(new Font(fontName, fontStyle, fontSize));

g.drawString(pressText, wideth - fontSize - x, height - fontSize/ 2 - y);