ImageSearch, OutputVarX, OutputVarY, X1, Y1, X2, Y2, ImageFile
  Parameters

    OutputVarX/Y
The names of the variables in which to store the X and Y coordinates of the upper-left pixel of where the image was found on the screen (if no match is found, the variables are made blank). Coordinates are relative to the active window unless CoordMode was used to change that.
Either or both of these parameters may be left blank, in which case ErrorLevel (see below) can be used to determine whether a match was found.

    X1,Y1
The X and Y coordinates of the upper left corner of the rectangle to search, which can be expressions. Coordinates are relative to the active window unless CoordMode was used to change that.

    X2,Y2
The X and Y coordinates of the lower right corner of the rectangle to search, which can be expressions. Coordinates are relative to the active window unless CoordMode was used to change that.

    ImageFile
The file name of an image, which is assumed to be in %A_WorkingDir% if an absolute path isn't specified. All operating systems support GIF, JPG, BMP, ICO, CUR, and ANI images (BMP images must be 16-bit or higher). Other sources of icons include the following types of files: EXE, DLL, CPL, SCR, and other types that contain icon resources. On Windows XP or later, additional image formats such as PNG, TIF, Exif, WMF, and EMF are supported. Operating systems older than XP can be given support by copying Microsoft's free GDI+ DLL into the AutoHotkey.exe folder (but in the case of a compiled script, copy the DLL into the script's folder). To download the DLL, search for the following phrase at www.microsoft.com: gdi redistributable