android 对已知路径下图片进行压缩

int maxWidth=624,maxHeight=840;//定义目标图片的最大宽高，若原图高于这个数值，直接赋值为以上的数值
Bitmap bitmap= BitmapFactory.decodeFile(path);
int originWidth=bitmap.getWidth();
int originHeight=bitmap.getHeight();
if(originWidth<maxWidth&&originHeight<maxHeight){
return ;
}
int width=originWidth;
int height=originHeight;

if(originWidth>maxWidth) {
width=maxWidth;
double i = originWidth * 1.0 / maxWidth;
height = (int) Math.floor(originHeight / i);
bitmap = Bitmap.createScaledBitmap(bitmap, width, height, false);

}
if(height>maxHeight){
height=maxHeight;
bitmap=Bitmap.createBitmap(bitmap,0,0,width,height);
}
File file=new File(path);
if(file.exists()){
file.delete();
}
try {
FileOutputStream out = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.PNG, 90, out);
out.flush();
out.close();

} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}