[x] Resize Wallpaper

Use this option, if you like to resize your wallpaper to your screen. You can tell Wallpaper Changer to resize your wallpaper only if it is not deform more than a certain amount, if the defamation is greater, Wallpaper Changer will only resize to the size of the maximum amount you setup with the slider (a useful value is 30%).
   

[x] Tile Wallpaper

If you not choose  "Auto Tile" you must decide between "Resize", "Tile" or you disable both. Choose "Tile Wallpaper" to tile your pictures over the screen. This is useful for textures. If you like to choose this option you must disable "Auto Tile".
  

[x] using Algorithm

Choose between two powerful resize algorithms. Personally, I prefer the first one. 
  

[x] Auto Tile Wallpaper,
if smaller then 1/x of your
current resolution

Tell Wallpaper Changer to automatically tile your image if it is smaller than the specified portion of your Desktop. If the picture can't be tiled, Wallpaper Changer use the values you have chosen for the "Resize" option.
   

[x] Check screen resolution

Tell Wallpaper Changer when to check your screen size. The "Check screen resolution" option is for all screen savers, WinAMP plugins, TV applications, they switch to another resolution while running. To prevent wrong resized pictures while running such application in full screen, I prefer that Wallpaper Changer only check my screen resolution once on startup.