我现有一个BufferedImage bi里面已经有图片,图片是load一个bmp文件的,bmp图片有背景,我希望把背景设置为透明,然后花在屏幕上,但是我像下面那样
无论是bi.setRGB(i, j, c | 0x00ffffff)
还是bi.setRGB(i,j,c & 0xff000000)
都不能把背景设成透明
请问大家应该怎样操作?
无论是bi.setRGB(i, j, c | 0x00ffffff)
还是bi.setRGB(i,j,c & 0xff000000)
都不能把背景设成透明
请问大家应该怎样操作?
1. 生成png图片int width = 400;int height = 300;// 创建BufferedImage对象BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);// 获取Graphics2DGraphics2D g2d = image.createGraphics();// 画图g2d.setColor(new Color(255,0,0));g2d.setStroke(new BasicStroke(1));g2d.draw//释放对象g2d.dispose();// 保存文件 ImageIO.write(image, "png", new File("c:/test.png"));int width = 400;int height = 300;// 创建BufferedImage对象BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);// 获取Graphics2DGraphics2D g2d = image.createGraphics();// 画图g2d.setColor(new Color(255,0,0));g2d.setStroke(new BasicStroke(1));g2d.draw//释放对象g2d.dispose();// 保存文件 ImageIO.write(image, "png", new File("c:/test.png"));这只是绘制图形的代码,其背景是黑色的,如何才能背景透明呢?继续搜索,没有得到结果,不过搜出以下代码,它只是把自己绘制的图形设置为透明或半透明,背景并不透明,如下:2. 绘制半透明图形int width = 400;int height = 300;// 创建BufferedImage对象BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);// 获取Graphics2DGraphics2D g2d = image.createGraphics();// 设置透明度g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 1.0f)); // 1.0f为透明度 ,值从0-1.0,依次变得不透明// 画图g2d.setColor(new Color(255,0,0));g2d.setStroke(new BasicStroke(1));g2d.draw//释放对象//透明度设置 结束g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));g2d.dispose();// 保存文件 ImageIO.write(image, "png", new File("c:/test.png"));这样绘制的图形应该说是前景透明的,背景依然是黑色,:(
网上没有看到有益的代码,在csdn上一位说自己实现了,但却没有说怎么实现的,没办法只能自己摸索了,耗了半个多小时,几乎查看了BufferedImage 和Graphics2D 所有方法和属性,终于找到了解决方案,只不过是增加两行代码而已,如下:int width = 400;int height = 300;// 创建BufferedImage对象BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);// 获取Graphics2DGraphics2D g2d = image.createGraphics();// ---------- 增加下面的代码使得背景透明 -----------------image = g2d.getDeviceConfiguration().createCompatibleImage(width, height, Transparency.TRANSLUCENT);g2d.dispose();g2d = image.createGraphics();// ---------- 背景透明代码结束 -----------------// 画图g2d.setColor(new Color(255,0,0));g2d.setStroke(new BasicStroke(1));g2d.draw//释放对象g2d.dispose();// 保存文件 ImageIO.write(image, "png", new File("c:/test.png"));================================================白背景变透明
package com.goldgrid.socket.client;import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;import javax.imageio.ImageIO;
import javax.swing.ImageIcon;import org.apache.log4j.Logger;public class Alpha { protected static Logger logger = Logger.getLogger(ClientSocket.class);public byte[] transferAlpha(Image image) { ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); try {
ImageIcon imageIcon = new ImageIcon(image);
BufferedImage bufferedImage = new BufferedImage(imageIcon
.getIconWidth(), imageIcon.getIconHeight(),
BufferedImage.TYPE_4BYTE_ABGR);
Graphics2D g2D = (Graphics2D) bufferedImage.getGraphics();
g2D.drawImage(imageIcon.getImage(), 0, 0, imageIcon
.getImageObserver());
int alpha = 0;
for (int j1 = bufferedImage.getMinY(); j1 < bufferedImage
.getHeight(); j1++) {
for (int j2 = bufferedImage.getMinX(); j2 < bufferedImage
.getWidth(); j2++) {
int rgb = bufferedImage.getRGB(j2, j1);
int R =(rgb & 0xff0000 ) >> 16 ;
int G= (rgb & 0xff00 ) >> 8 ;
int B= (rgb & 0xff );
if(((255-R)<30) && ((255-G)<30) && ((255-B)<30)){
rgb = ((alpha + 1) << 24) | (rgb & 0x00ffffff);
} bufferedImage.setRGB(j2, j1, rgb); }
} g2D.drawImage(bufferedImage, 0, 0, imageIcon.getImageObserver());
//ImageIO.write(bufferedImage, "png", new File("d:/test.png.png")); ImageIO.write(bufferedImage, "png", byteArrayOutputStream);
} catch (Exception e) {
logger.error(e.toString());
}finally{
} return byteArrayOutputStream.toByteArray();}
}
1.取得控件背景色
2.指定需要透明的颜色
3.逐点扫描image,把需要透明的颜色setRGB成控件背景色预想:效率很低我记得我以前用过很简单的方法,设置透明色的,不过忘了怎么用的了,呵呵
BufferedImage temp = ImageIO.read(
new File("chess.bmp"));//取得图片
int imgHeight = temp.getHeight();//取得图片的长和宽
int imgWidth = temp.getWidth();
int c = temp.getRGB(3, 3);
BufferedImage bi = new BufferedImage(imgWidth, imgHeight,
BufferedImage.TYPE_4BYTE_ABGR);//新建一个类型支持透明的BufferedImage
for(int i = 0; i < imgWidth; ++i)//把原图片的内容复制到新的图片,同时把背景设为透明
{
for(int j = 0; j < imgHeight; ++j)
{
if(temp.getRGB(i, j) == c)
bi.setRGB(i, j, c & 0x00ffffff);//这里把背景设为透明
else
bi.setRGB(i, j, temp.getRGB(i, j));
}
}
谢谢上面两位,通过参考你们的提示我终于做出来了,上面的代码可以把背景设为透明的
这是我取得背景色的代码