I came across the need to be able to find something on the screen based on a reference image in my AutoIt scripts. However, this is not an available feature of AutoIt. There are functions available for checking individual pixels, but not images.

I found a solution in this thread. The key is the AutoHotkey ImageSearch function. Someone extracted the ImageSearch code from AutoHotkey, packed it up in to convenient DLLs, and put together a UDF ¹⁾ library that acts as a wrapper.

I took the UDF library and made the following improvements to it:

• Updated relevant functions to return an array of [x,y] coordinates on success, and False on failure. Original search functions returned True/False success status, while coordinate results were stored in external variables passed in by reference.
• Updated relevant functions with an extra parameter for a window handle, making it possible to limit the search area to the boundaries of a specified window.
• Added the ability to handle multi-monitor desktops by re-defining desktop boundaries in to new Global variables $desktopLeft, $desktopTop, $desktopRight, $desktopBottom, $desktopWidth, and $desktopHeight.

The best intro to the syntax is in my example code…

; includes
#include <ImageSearch.au3>	; for _ImageSearch, _ImageSearchArea, _WaitForImageSearch, _WaitForImagesSearch
 
; Ref: https://www.autoitscript.com/autoit3/docs/functions/AutoItSetOption.htm
; Enforce pre-declaration of variables, helps develop good coding habits
AutoItSetOption("MustDeclareVars", 1)
; Set the mouse coordinate mode to screen absolute
;	0 = relative to active window
;	1 = absolute screen
;	2 = relative to client area of active window
AutoItSetOption("MouseCoordMode", 1)
 
; This will be the target image file to search for
Local $target = ".\ImageSearch_target.png"
 
; Declare an init a variable to hold the search result
Local $result = 0
 
; EXAMPLE 1
; Find the image in a specified area, and move the mouse to its location
$result = _ImageSearchArea($target, 1, $desktopLeft, $desktopTop, $desktopWidth, $desktopHeight, 0)
If IsArray($result) Then MouseMove($result[0], $result[1])
 
; EXAMPLE 2
; Find the image across the entire desktop
$result = _ImageSearch($target, 1)
If IsArray($result) Then MouseMove($result[0], $result[1])
 
; The above examples accomplish the same goal, in fact _ImageSearch actually
; calls _ImageSearchArea with predetermined parameters

More in-depth function documentation is included in the comments of ImageSearch.au3.

I've put it up on GitHub.