ImageSearchDLL & UDF - The Complete Guide

Author: Dao Van Trong - TRONG.PRO

Last Updated: 2025-08-04

1. Introduction

ImageSearchDLL is a high-performance image recognition solution for Windows, designed to be both powerful for modern systems and compatible with legacy environments. The project consists of three distinct C++ DLL versions and a smart AutoIt User-Defined Function (UDF) that automatically selects the best DLL for the job.

This architecture ensures that your scripts get the best possible performance on modern systems (like Windows 10/11) while maintaining full functionality on older systems like Windows 7 and even Windows XP.

New is the Special Feature is the function of searching for pictures in pictures!

2. How it Works: The Smart UDF Loader

The core of this project is the AutoIt UDF (ImageSearch_UDF.au3). You don’t need to worry about which DLL to use; the _ImageSearch_Startup() function handles it all automatically.

Here is the loading logic:

1. On Modern OS (Windows 8, 10, 11+):
   • It first looks for the Modern DLL (ImageSearch_x64.dll or ImageSearch_x86.dll).
   • If not found, it falls back to the Windows 7 DLL.
   • If neither is found, it deploys the Embedded XP DLL.
2. On Windows 7:
   • It prioritizes the Windows 7 DLL (ImageSearch_Win7_x64.dll or ImageSearch_Win7_x86.dll).
   • If not found, it deploys the Embedded XP DLL.
3. On Windows XP:
   • It exclusively uses the Embedded XP DLL, which is extracted from a HEX string inside the UDF.

This ensures maximum performance where possible and maximum compatibility where needed.

3. The DLL Versions Explained

There are three distinct DLLs, each compiled for a specific purpose.

4. Getting Started (For AutoIt Users)

Using the library is simple. Just make sure your files are organized correctly.

File Structure

For the best experience, place the DLL files in the same directory as your script and the UDF.

/YourScriptFolder/
|
|-- MyScript.au3
|-- ImageSearch_UDF.au3
|-- ImageSearch_x64.dll (Modern DLL for 64-bit)
|-- ImageSearch_x86.dll (Modern DLL for 32-bit)
|-- ImageSearch_Win7_x64.dll (Win7 DLL for 64-bit)
|-- ImageSearch_Win7_x86.dll (Win7 DLL for 32-bit)
|
/-- images/
|-- button.png

Quick Start Example

Here is a basic AutoIt script to get you started.

#include "ImageSearch_UDF.au3"

; 1. Initialize the library. The UDF will automatically load the best DLL.  
_ImageSearch_Startup()  
If @error Then  
    MsgBox(16, "Error", "ImageSearch DLL could not be initialized. Exiting.")  
    Exit  
EndIf

; You can check which version was loaded  
ConsoleWrite(">> Loaded DLL Version: " & _ImageSearch_GetVersion() & @CRLF)  
ConsoleWrite(">> System Info: " & _ImageSearch_GetSysInfo() & @CRLF)

; 2. Perform a search for an image on the entire screen.  
Local $sImagePath = @ScriptDir & "\images\button.png"  
Local $aResult = _ImageSearch($sImagePath)

; 3. Process the results. The result is ALWAYS a 2D array.  
If $aResult[0][0] > 0 Then  
    ConsoleWrite("Found " & $aResult[0][0] & " match(es)!" & @CRLF)  
    ; Loop through each match  
    For $i = 1 To $aResult[0][0]  
        Local $iX = $aResult[$i][1] ; X coordinate  
        Local $iY = $aResult[$i][2] ; Y coordinate  
        ConsoleWrite("Match #" & $i & " found at: " & $iX & ", " & $iY & @CRLF)  
        MouseMove($iX, $iY, 20)  
        Sleep(1000)  
    Next  
Else  
    ConsoleWrite("Image not found." & @CRLF)  
EndIf

; 4. Shutdown is handled automatically when the script exits. No need to call _ImageSearch_Shutdown().

5. Full API Reference

Main Functions

• _ImageSearch_Area(…): The main function with all available options.
• _ImageSearch(…): A simplified wrapper for searching the entire screen.
• _ImageInImageSearch_Area(…): Searches for an image within another image file.

Common Parameters

Return Value

All search functions return a 2D array.

• $aResult[0][0]: Contains the number of matches found.
• For each match $i (from 1 to $aResult[0][0]):
  • aResult[aResult[i][1]: X coordinate
  • aResult[aResult[i][2]: Y coordinate
  • aResult[aResult[i][3]: Width of the found image
  • aResult[aResult[i][4]: Height of the found image

Utility Functions

• _ImageSearch_GetVersion(): Returns the version string of the currently loaded DLL.
• _ImageSearch_GetSysInfo(): Returns system info from the DLL (AVX2 support, screen resolution).
• _ImageSearch_ClearCache(): Deletes all cache files from the temp directory.