Here you can find the source of calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight)
private static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight)
//package com.java2s; import android.graphics.BitmapFactory; public class Main { private static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) { final int height = options.outHeight; final int width = options.outWidth; int inSampleSize = 1; if (height > reqHeight || width > reqWidth) { final int heightRatio = Math.round((float) height / (float) reqHeight); final int widthRatio = Math.round((float) width / (float) reqWidth); inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;// w w w .j av a 2 s .co m } return inSampleSize; } }