Modes in Photoshop are very important and the two most popular that we'll discuss now is Indexed Color mode and RGB mode. If you would like to scale an image and have your image antialiased, then you probably want to make sure the image is in RGB mode. Most file formats with the big exception of the GIF format, are compatible with this mode. After you select RGB under [Mode], then you can resize the image under [Image]...[Image Size]. When you select 72 ppi or resize in another way, your image will automatically be antialiased. Below is the Image Size dialog box.