原理：读取colorbar图片。将颜色变化存取到与colorbar高度相同的数组中mColorbar，只需读取第一列颜色值即可。
获取一张需要改变颜色值的bitmap. 将bitmap每个点的颜色值转为灰度值，再根据以下公式获取该灰度值在colorbar的颜色数组colorarray中对应的颜色值
代码如下
1读取colorbar
private int[] mColorbar;
Bitmap mColorbitmap;
privatevoid readColorbar() {
byte[]bardata;
try{
InputStreamis = mContext.getResources().openRawResource(R.drawable.colorbar);
ByteArrayOutputStream os = newByteArrayOutputStream(is.available());
byte[] buffer = new byte[4096];
int bytesRead;
while ((bytesRead = is.read(buffer)) !=-1) {
os.write(buffer, 0, bytesRead);
}
is.close();
bardata = os.toByteArray();
BitmapFactory.Optionsoptions = new BitmapFactory.Options();
options.inPreferredConfig= Bitmap.Config.RGB_565;
mColorbitmap= BitmapFactory.decodeByteArray(bardata, 0, bardata.length, options);
mColorbar = new
int [mColorbitmap.getHeight()];
for(int i = 0; i < mColorbitmap.getHeight(); i++) {
int color =
mColorbitmap.getPixel(0, i);
mColorbar[i]= color;
intr = Color.red(color);
intg = Color.green(color);
intb = Color.blue(color);
inta = Color.alpha(color);
//Log.d(TAG,"readColorbar [" +i +"] r=" + r + "g=" + g+"b=" +b);
}
} catch (IOException e) {
Log.e(TAG,"load colorbar exception");
}
}
2.根据灰度值获取颜色
Bitmap mBitmap = bitmap.copy(Bitmap.Config.RGB_565,true);
for(int i = 0; i < bitmap.getHeight(); i++) {
for (int j = 0; j < bitmap.getWidth(); j++) {
intcolor = bitmap.getPixel(j, i);
/*
int r = Color.red(color);
intg = Color.green(color);
intb = Color.blue(color);
inta = Color.alpha(color);
*/
intr = (color&0x00FF0000)>>16;
int g =(color&0x0000FF00)>>8;
int b =(color&0x000000FF);
int grey =(int)((float)r*0.3+(float)g*0.59+(float)b*0.11);
//grey =alpha|(grey<<16)|(grey<<8)|grey;
//灰度值除以255，获得当前灰度比重。再乘以colorbar高度。
int
colorIndex = (grey* mColorbitmap.getHeight())/ 255 ;
mBitmap.setPixel(j, i,
mColorbar[colorIndex]);
//Log.d(TAG,"onPicFrameChanged [j,i] grey = " + grey + "colorindex = "+ colorIndex);
//Log.d(TAG, "onPicFrameChanged[" + j +"," + i +"] r=" + r + "g=" + g+"b=" +b);
}
}