把文字绘制在创建好的Image，然后放大缩小该Image

把文字绘制在创建好的Image，然后放大缩小该Image，实现方法如下：

/**
* 把文字转发为一张图片 并设置此张图片大小
* @param g
* @param txt
* 文字
* @param font
* 字体
* @param gbcolor
* 背景颜色
* @param fColor
* 字体颜色
* @param desW
* 目标宽度
* @param desH
* 目标高度
* @return
*/
public static Image StrToImgAndSetSize(Graphics g,String txt,Font font,
int gbcolor, int fColor,int desW, int desH){
Image desImg=null;
try{
Image srcImg=Image.createImage(font.stringWidth(txt), font.getHeight());
Graphics graphics=srcImg.getGraphics();
graphics.setColor(gbcolor);
graphics.fillRect(0, 0, font.stringWidth(txt), font.getHeight());
graphics.setColor(fColor);
graphics.setFont(font);
graphics.drawString(txt, 0, 0, Graphics.LEFT|Graphics.TOP);
desImg=zoomImage(srcImg, desW, desH);

}catch(Exception ex){
desImg=null;
}
return desImg;
}

/**
* 2.0方法 用生成RGBImage解决 图片的放大缩小
*/
public static Image zoomImage(Image src, int desW, int desH) {
Image desImg = null;
int srcW = src.getWidth(); // 原始图像宽
int srcH = src.getHeight(); // 原始图像高
int[] srcBuf = new int[srcW * srcH]; // 原始图片像素信息缓存
src.getRGB(srcBuf, 0, srcW, 0, 0, srcW, srcH);
// 计算插值表
int[] tabY = new int[desH];
int[] tabX = new int[desW];
int sb = 0;
int db = 0;
int tems = 0;
int temd = 0;
int distance = srcH > desH ? srcH : desH;
for (int i = 0; i <= distance; i++) { /* 垂直方向 */
tabY[db] = sb;
tems += srcH;
temd += desH;
if (tems > distance) {
tems -= distance;
sb++;
}
if (temd > distance) {
temd -= distance;
db++;
}
}
sb = 0;
db = 0;
tems = 0;
temd = 0;
distance = srcW > desW ? srcW : desW;
for (int i = 0; i <= distance; i++) { /* 水平方向 */
tabX[db] = (short) sb;
tems += srcW;
temd += desW;
if (tems > distance) {
tems -= distance;
sb++;
}
if (temd > distance) {
temd -= distance;
db++;
}
}
// 生成放大缩小后图形像素buf
int[] desBuf = new int[desW * desH];
int dx = 0;
int dy = 0;
int sy = 0;
int oldy = -1;
for (int i = 0; i < desH; i++) {
if (oldy == tabY[i]) {
System.arraycopy(desBuf, dy - desW, desBuf, dy, desW);
} else {
dx = 0;
for (int j = 0; j < desW; j++) {
desBuf[dy + dx] = srcBuf[sy + tabX[j]];
dx++;
}
sy += (tabY[i] - oldy) * srcW;
}
oldy = tabY[i];
dy += desW;
}
// 生成图片
desImg = Image.createRGBImage(desBuf, desW, desH, true);
return desImg;
}