Resizing Images in Gimp
Suppose you have a whopping big image:

Original image can be found at, copyright olya.

If you are viewing this page on the web using a modem connection, you have probably already noticed that it doesn't load up in a time to which one would refer as "an instant."

The size of the image is 183k.

Suppose you wish to get the size of this image down to something that can be easily viewed on a 640x480 pixel computer monitor. That means the width needs to be, at most, 640 pixels. The height needs to be, at most, 480 pixels.

Open the image in The Gimp.

Right-click the image. Select Image/Scale Image...

As you can see, based upon our criteria, the image is both too high and too wide. In particular, it is way too wide!

In this window, the ratio of height and width are linked (unless you click the little chain to the right of the "Ratio" section), so if you change one of the dimensions, the other will automatically recalculate accordingly. Let's erase the width and type "600" in its place. Six hundred is within our criteria of being less than 640, right? Press the <Tab> key, so that the height will recalculate.

Notice that the height automatically lowered to the proper dimension in maintaining a consistant width to height ratio. We note that, fer the same reason, The Gimp switched our "600" to "601". If we are Hel-bent on 600 and not 601, the extra pixel can be cropped off in a seperate procedure.

Click <OK>.

There is our resized picture.

The final step is to save it so we can put it to use in whatever project that needed the resized picture.

Right-click the image and select File/Save As. Give it a new name and supply a ".jpg" on the end.

And that's it. If I save the image at the default 75% Quality, the size of our sample image becomes 18k. That's a big difference from the original 183k.