1.With your image open in Photoshop, look to the menu bar at the top of the screen. Click Image > image Size. This will open a new dialogue window which should look similar to this:

2. First thing to do is make sure the three tick boxes at the bottom of the box are ticked. Also select 'Bicubic (best for smooth gradients).

3. Make sure the resolution matches the instructions you have been given. In the absence of instructions, make it 240 pixels/inch.

Now to the main bit, the actual size of the final image. There are two boxes at the top marked width and height. These should be made to match any instructions you have been given. For example: the most common instruction is for an image size of 1024 × 768 pixels.
This means a landscape shape image would be 1024 pixels in the width box, and let the height box do whatever it will, so long as it doesn't exceed 768 pixels. If it does exceed 768 pixels, then type 768 in the height box and let the width box do whatever it will. The width box will in this case be less than 1024 pixels, but that's OK.
If your image is in portrait shape, then type 768 in the height box and let the width box do whatever it will, so long as it doesn't exceed 1024 pixels. I've never known that to happen, but keep an eye on it.

4. Does your dialogue box now look like one of the following:

This for a landscape shape image -(width 1024, height any value less than 768)



or this for a portrait shape image -(height 768, width any value less than 1024)



If so, click OK, and that's it.

9. Next, you need to save your picture. Click  here  to learn how.

Graeme Webb
Dec 2009