When you convert an image from Adobe Photoshop to Adobe Illustrator, the file extension will change from “.pds” to “.ai”. In addition to altering the file extension, converting a PDS file to the AI format will permit you to access the extensive tools available in Illustrator, many of which are especially useful if you are working on vector images. These images, which consist of line art and outlines of objects to be filled with colors or patterns, are easiest to work with in Illustrator. Tips