Scaling down bitmap causes portion of image not visible

问题

So, I'm scaling down bitmap files so that I can display images without going over the memory size. I referred to the android tutorial here.

What I found out was that not only is this scaling down my image so the size won't be too big but it is also cutting a portion of the image off. Or so it seems. I only want the image to take up a part of the screen. How can I scale down the bitmap and display the whole image?

If you could provide any help, ideas, or suggestions I'll be very thankful! And if I seem to be making a simple mistake, please point it out to me. Thanks!

Here's the code:

    String fileName = data.getStringExtra("file");
    image.setImageBitmap(decodeSampledBitmapFromFile(fileName, screenWidth, screenHeight / 2));

    public static Bitmap decodeSampledBitmapFromFile(String file, int reqWidth, int reqHeight){
    //first decode with inJustDecodeBounds = true to check dimensions
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(file, options);

    //calculate inSampleSize
    options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

    //decode bitmap with inSampleSize set
    options.inJustDecodeBounds = false;
    System.gc();
    return BitmapFactory.decodeFile(file, options);

}


public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight){
    //raw height and width of image
    final int imageHeight = options.outHeight;
    final int imageWidth = options.outWidth;
    int inSampleSize = 1;

    if (imageHeight > reqHeight || imageWidth > reqWidth){
        if (imageWidth > imageHeight){
            inSampleSize = Math.round((float) imageHeight / (float) reqHeight);
        }else{
            inSampleSize = Math.round((float) imageWidth / (float) reqWidth);
        }//end of second if statement
    }//end of first if statement
    return inSampleSize;
}//end of calculateInSampleSize

    public void getDisplaySize(){
    Display display = getWindowManager().getDefaultDisplay();
    Point size = new Point();
    //get the screen dimensions
    try{
        display.getSize(size);
        screenWidth = size.x;
        screenHeight = size.y;
        buttonHeight = view.getHeight();
        screenLength = (int) (screenHeight / 5);
        imageWidth = (int) (screenWidth / 4);
    }catch (NoSuchMethodError e){
        //for older versions of android
        screenWidth = display.getWidth();
        screenHeight = display.getHeight();
        buttonHeight = view.getHeight();
        screenLength = (int) (screenHeight / 5);
        imageWidth = (int) (screenWidth / 4);
    }//end of try/catch block

}//end of getDisplaySize() method

来源：https://stackoverflow.com/questions/13203957/scaling-down-bitmap-causes-portion-of-image-not-visible