pictureUtils

public class PictureUtils {           //根据给定的宽高获得bitmap

    public static Bitmap getScaledBitmap(String path, int destWidth, int destHeight){
        //Read in the dimensions of the image on disk;
        BitmapFactory.Options options = new BitmapFactory.Options();

        float srcWidth = options.outWidth;
        float srcHeight = options.outHeight;
        //figure out how much to scale down by
        int inSampleSize = 1;
        if (srcHeight > destHeight || srcWidth > destWidth){
            if (srcWidth > srcHeight){
                inSampleSize = Math.round(srcHeight/destHeight);
            }else{
                inSampleSize = Math.round(srcWidth/destWidth);
            }
        }
        options = new BitmapFactory.Options();
        options.inSampleSize = inSampleSize;
        //read in and crate final bitmap
        return BitmapFactory.decodeFile(path,options);
    }

    public static Bitmap getScaleBitmap(String path,Activity activity){   根据屏幕获取 bitmap
        Point size = new Point();
        activity.getWindowManager().getDefaultDisplay().getSize(size);
        return getScaledBitmap(path,size.x,size.y);
    }
}