Java tutorial
//package com.java2s; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.util.DisplayMetrics; import android.view.WindowManager; public class Main { public static Bitmap decodeSampledBitmapByPath(Context context, String path) { DisplayMetrics displayMetrics = new DisplayMetrics(); WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); wm.getDefaultDisplay().getMetrics(displayMetrics); final int height = displayMetrics.heightPixels; final int width = displayMetrics.widthPixels; // First decode with inJustDecodeBounds=true to check dimensions final BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true; BitmapFactory.decodeFile(path, options); // Calculate inSampleSize options.inSampleSize = calculateInSampleSize(options, width, height); // Decode bitmap with inSampleSize set options.inJustDecodeBounds = false; return BitmapFactory.decodeFile(path, options); } public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) { // Raw height and width of image final int height = options.outHeight; final int width = options.outWidth; int inSampleSize = 1; if (height > reqHeight || width > reqWidth) { final int halfHeight = height / 2; final int halfWidth = width / 2; // Calculate the largest inSampleSize value that is a power of 2 and keeps both // height and width larger than the requested height and width. while ((halfHeight / inSampleSize) > reqHeight && (halfWidth / inSampleSize) > reqWidth) { inSampleSize *= 2; } } return inSampleSize; } }