If you want to change the size of an image in Photoshop CS, you can do so by choosing Image -> Image Size from the Photoshop menu bar, or by right clicking on the image canvas title bar, and selecting Image size from the pop up menu. Both of these actions will display the image size dialog box shown below.

 

 

 

Before adjusting the settings for your image size, there are a few things you should consider. The fields under the Pixel Dimensions heading will directly affect the size of your image on the computer screen. If you decrease the amount of pixels in the width and height fields, the image will be smaller on you screen and could suffer in quality. If you increase the number of pixels, the image will appear larger on your screen, but you can still have a reduction in quality. (This reduction in quality would come from the re-sampling of the image.)

 

If you click the down arrows next to the data fields in the Pixel Dimensions area, you will have the option of changing the amount of pixels as a percentage rather than an as an absolute value. Note that if you do not save the image after it has been resized the image will not be saved with the new dimensions until you close Photoshop and accept the changes.