Resizing with Splashup
Resizing an image is one of the very basic things you will need to know in order to take a photo from your digital camera, and use it on the web. Some digital cameras will have settings that will allow you to take photos that are suitable for web use, but many will not. Know your camera! Any image that you use on the web should generally should be no wider than 600 pixels at the absolute most, and some cameras will produce photos that exceed 2000 pixels in width.
Basic Resizing
After you've opened the image that you would like to resize, click on Image at the top of your screen, and select Size... in the flyout that appears.
A small window will pop-up, and the first thing you need to do is click the box next to Constrain. Then in the width box, type in the width you want your image to be. Next is a little strange thing...you need to put your cursor in the height box, and it will switch to the height dimensions that will keep the image in proportion. Then click the OK button, and you've successfully resized your image.