Java tutorial
//package com.java2s; //License from project: Apache License import android.graphics.Bitmap; public class Main { public static Bitmap resizePreservingRatio(Bitmap original, int newWidth, int newHeight) { if (original == null) return null; int originalWidth = original.getWidth(); int originalHeight = original.getHeight(); if (newWidth / (float) originalWidth < newHeight / (float) originalHeight) { newHeight = originalHeight * newWidth / originalWidth; } else { newWidth = originalWidth * newHeight / originalHeight; } return Bitmap.createScaledBitmap(original, newWidth, newHeight, true); } }