J2ME图片缩放和透明效果

这个函数是我以前在网上搜罗到的，且不谈效果，性能什么的。只觉得它非常好用。
用了很长时间，可惜不知道是谁。真要谢谢这位作者了。
这个函数使用了midp2.0的getRGB()函数，效率不错，基本上没什么可优化的了。

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, false);
  return desImg;
 }





第二个例子

public class ImageUtil {

public static final Image zoomImage(Image src){
return zoomImage(src,src.getWidth(),src.getHeight(),true,false);
}
public static final Image zoomImage(Image src, int desW, int desH, boolean isBackgroundTrans, boolean isTrans) {
Image desImg = null;
int srcW = src.getWidth(); // source image width
int srcH = src.getHeight(); // source image height
int[] srcBuf = new int[srcW * srcH]; // source image pixel
src.getRGB(srcBuf, 0, srcW, 0, 0, srcW, srcH);
// compute interpolation table
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++) { /* vertical direction */
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++) { /* horizontal direction */
tabX[db] = (short) sb;
tems += srcW;
temd += desW;
if ( tems > distance) {
tems -= distance;
sb++;
}
if ( temd > distance) {
temd -= distance;
db++;
}
}
// set transparence
// if(isTrans){
// int a= 100;//set the transparence of pixel 100
// for(int i=0;i<srcBuf.length;i++){
// if(srcBuf[i]==0x00FFFFFF)continue;
// srcBuf[i]=(a<<24) | (srcBuf[i] & 0x00FFFFFF);// modify the highest 2 value
// }
// }

// formation enlarge and shorten buffer pixel
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;
}
if(isTrans){
// int a= 100;//set the transparence of pixel 100
for(int i=0;i<desBuf.length;i++){
if(desBuf[i]==0x00FFFFFF)continue;
int alpha = ((desBuf[i] & 0xff000000) >>> 24)==0?0:100;
desBuf[i]=((alpha+1)<<24) | (desBuf[i] & 0x00FFFFFF);// modify the highest 2 value
}
}
if(isBackgroundTrans){
desImg = Image.createRGBImage(desBuf, desW, desH, true);
}else{
desImg = Image.createRGBImage(desBuf, desW, desH, false);
}

return desImg;
}
}