image file size


You’ve got this brilliant design, or have taken a great photograph with your new digital camera and want to send it to someone. No problem, type a quick e-mail, attach the file and hit the Send button? No. Problem. Even if you’ve got a super fast broadband connection your friends or colleagues may not. If you’ve ever downloaded a single music track you’ll know that it can take between 10 and 20 minutes on a dial-up connection. Many good quality original graphics and today’s digital camera pictures can be the same sort of file size and that can mean a very long wait for the poor person waiting for messages to arrive at the other end.

OK, so all your friends have broadband – but what’s the point of sending a picture that would measure about 3 feet by 2 feet on their 17 inch monitor? So, unless you’re dealing with proofs or design studio stuff you need to learn a bit about image file sizes and how to reduce them.

Remarkably, Microsoft haven’t got their act together on this one in any meaningful way. Their Picture Editor is awkward to find on most people’s pcs and even more awkward to use. XP provides a Picture and Fax viewer but that doesn’t do what we want it to. You need a decent photo editing program. Serif have a good and inexpensive product called Photo Plus. The latest version is Photo Plus 9 but you’ll probably find earlier versions going free which will do the job. Try . Irfanview is a well-respected and completely free alternative and there are others. (The Irfanview licence even permits use over educational networks and the whole program fits on an old floppy disk!) Available at .

Irfanview is not the most user-friendly of products but it’s manageable.

1 Start the program

It’s a pretty basic screen! Fortunately, the menus and icons you need are familiar.

2 Open your original image

Use File | Open or the yellow folder icon and navigate to your image. It’ll probably take over the whole screen, and some.

3 Zoom out so that you can see it all

Click on the Zoom out icon to bring the whole image into view. Whilst this step isn’t strictly necessary it helps to give an idea of the final size you might want.

In this case a few clicks produced a reduction to 20% original dimensions – 320 x 240 pixels.

4 Use Image | Resize to reduce its dimensions

The window that opens shows far more information than you need. Select Set new size (probably the default setting)

In this example an image slightly larger than the 20% illustration has been selected by typing 400 in the Width box – the Height will be adjusted automatically if there is a tick in the Preserve aspect ratio box. 400 x 300 pixels is a reasonable size, about 6 by 4 ½ inches on most monitors. You’ll need to experiment and decide for yourself what size suits your purpose.

If you download the add-ins for the program you’ll be able to set the quality of the final image and fine tune things further. Use File | Save as . . . to save the new image and use a sensible name. It can be a good idea to adopt a convention for this sort of work as you may be doing it a lot! A suggestion is simply to add an i to the original file name for each reduction: file, filei, fileii, fileiii etc. If you have a choice, save a photograph as a jpg (or jpeg) type of file. A gif file type may be more suitable for graphics. It’s not necessary at this stage to understand why – the results will be obvious so just experiment.

5 See the difference

The new image is a mere 4% of its original size. Only a trained eye will see any difference on screen.

6 Keep an eye on things

You may well not be aware of the size of messages arriving in your e-mail Inbox. Outlook’s default settings don’t show them but it’s a good idea to change this. In Outlook Express use View | Columns and tick the Size box.

To see who’s occupying more than their fair share of your storage space click on the Size column heading in any Outlook message listing and the biggest should appear at the top. (You may need to click again if this produces the smallest at the top and scrolling to get back up to the top may be necessary). Here’s an example:

The No 1 in the above list was a message containing an innocent looking Word document. The Word document contained a little leaflet. It was the logo on the leaflet which was the culprit! The snapshot below shows the offending qblue document weighing in at a massive 3.5MB.

By copying the image to Irfanview and adjusting it in a similar manner as described in these notes the document size was reduced to just 28KB (qblue2). This is 120 times smaller and the mathematicians out there will see that the image was actually less than 1/400th of its original size! So far no-one has noticed any difference even in the printed document.

These illustrations have been cropped to hide the identities of senders but suffice it to say that, as more observant readers will have spotted, most were people closely involved in Information and Learning Technology!

Remember that there will be times when you have to use big files – original artwork, music, video and images for professional printing. There’s not much anyone could have done about the 4 minute pop music video at 47MB I received. However the unnecessarily biggest file I’ve had in my Inbox is a 12-page Publisher document at 32MB. If you’d like to contribute yours to my top twenty send details to me at and I shall update the list on the web.

And yes, the images used in this document are heavier than they should be. Nobody’s perfect.

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 page updated
29 May, 2006
©Andrew Hill International • Astcote •UK • MMIV