Copyright 2001, David Pierce

How to create JPG files for postcards

David Pierce
August 5, 2001

Note: This document is not intended as an advertisement for any particular services. It is only intended for family and friends who want to set up their own web sites and who might be asking me for help with it in the future.


When you first create a digital picture, you typically create an image file that is much too big to use on a web site. Modern digital cameras generate JPG files that can exceed 2 megabytes, but you almost never want to ask a user to have to download more than about 100 KB per picture. Moreover, you typically want to publish pictures of at most 1024x768 resolution, since many monitors don't display more than that.

You will often want to generate thumbnails of your pictures so that your viewer can preview your pictures before downloading them.

This document explains one way to generate pictures and thumbnails that are suitable for use on web pages. Unfortunately, the software that I use is only available for Windows. If you work with a Mac, you're on your own.

Download IrfanView

Download and install the latest version of IrfanView from Let it assign itself as the default application associated with JPG files.

Run IrfanView

In a folder containing some of your pictures, double-click on a JPG file. This should summon IrfanView. Play around with the options in the View menu to figure out which display options you like. Use

File >> Batch Conversion / Rename

to bring up the dialog box that lets you convert a large number of files to a different size or representation. Use this to generate first your thumbnails, then your postcard-size pictures. Here are the settings I use.

Warning: It is possible that the program's user interface (including the names for the various settings) has changed since I downloaded my version of the program.


Use the default options for any not listed below.


Use the same settings, except use 600 and 450 for the width and height, respectively.