ScreenCapture 4k res - how to get dpi awareness?

[LegitStack]

Been struggling with this one for a while. 

when I do a _screencapture_capture call on a high resolution monitor (like my surface book) it gives me an image that has 2 problems:

1. its in the wrong location on the screen

and

2. it gives me a picture that is larger than the area of the screen I selected, though it only has the content of what I selected. 

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I was able to easily fix problem #1 by manually adjusting the x y coordinates to compensate for the amount of DPI scale I have.

for instance if I'm 200% zoomed in the code looks like this:

Local $bmp = _ScreenCapture_Capture("", $iX1*2, $iY1*2, $iX2*2, $iY2*2, false)

 it's problem #2 that is the big problem. I'd like to attach a screen shot of what I'm talking about (see capture.png)

---------------------------

Now I basically understand why this is happening. ScreenCapture grabs each pixel of the screen. This screen, being a high resolution, when its zoomed in adds up several pixels to make one on the screen. 

This is a problem for me because I'm taking images of the screen and later looking for those exact images on the screen. if everything is blown up by an indeterminate amount (in my case 2x) then those images can't be found later on. 

Does anyone know what I can do? 

I tried resizing the images back down to no avail. 

_GDIPlus_ImageResize and _GDIPlus_ImageScale don't work because they don't compress the pixels correctly. quality is lost. and the exact image isn't preserved, so I can't search for it later. (see capture1.png)

 

Anyway, I'm about to give up, been on this problem for too long! does anyone know what I can do? Seems to me that the ideal solution would be to eventually have autoit add an argument to _screencapture_capture that lets you specify a DPI scale amount or something.  that can be pulled from the registry at HKEY_CURRENT_USER\control panel\desktop\windowmetrics\appliedDPI.

But in the meantime, does anyone have any suggestions for how I can make my program compatible with 4k resolution monitors? I either need to take the screen capture like normal, then scale it down appropriately without losing quality, or I need to capture the screen in the first place like the human sees it. But I don't know how to do that either. 

I'll post my relevant code here: (in my project I call ScreenCapture_DPI_Aware)

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#include <Security.au3>

Func _GetAppliedDPI()
  Local $aArrayOfData = _Security__LookupAccountName(@UserName)

  If IsArray($aArrayOfData) Then
    ;msgbox(64, "SID String = ", $aArrayOfData[0] & @CRLF)
    ;msgbox(64, "Domain name = ", $aArrayOfData[1] & @CRLF)
    ;msgbox(64, "SID type = ", _Security__SidTypeStr($aArrayOfData[2]) & @CRLF)
    ;Local $AppliedDPI = RegRead("HKEY_USERS\" & $aArrayOfData[0] & "\Control Panel\Desktop\WindowMetrics", "AppliedDPI")
    Local $AppliedDPI = RegRead("HKEY_CURRENT_USER\Control Panel\Desktop\WindowMetrics", "AppliedDPI")
    return $AppliedDPI
  EndIf
EndFunc



Func GetScale()
  $applied = _GetAppliedDPI()
  if $applied == "" then
    return 1
  else
    return $applied / 96
  EndIf
EndFunc



Func ScreenCapture_Capture_DPI_Aware($sBMP_Path, $iX1, $iY1, $iX2, $iY2, $bool)
  $R = GetScale() ;Raito

  Local $bmp = _ScreenCapture_Capture($sBMP_Path, $iX1*$R, $iY1*$R, $iX2*$R, $iY2*$R, $bool)

  ;Scaling didn't work:
  ;_ScaleImage($bmp, $sBMP_Path, abs($iX2 - $iX1), abs($iY2 - $iY1), $R)
  ;return _ScreenCapture_Capture($sBMP_Path, $iX1*$R, $iY1*$R, $iX2*$R, $iY2*$R, $bool)
  
EndFunc







;Func _ScaleImage($bmp, $outimage, $w, $h, $scale)

;  _GDIPlus_Startup()
    ;Get the encoder of to save the resized image in the format you want.
;    Local $Ext = StringUpper(StringMid($outimage, StringInStr($outimage, ".", 0, -1) + 1))
;    $CLSID = _GDIPlus_EncodersGetCLSID($Ext)
    ; code found here : https://www.autoitscript.com/autoit3/docs/libfunctions/_GDIPlus_ImageSaveToStream.htm
;    Local $sImgCLSID = _GDIPlus_EncodersGetCLSID("png") ;create CLSID for a JPG image file type
;    Local $tGUID = _WinAPI_GUIDFromString($sImgCLSID) ;convert CLSID GUID to binary form and returns $tagGUID structure
;    Local $tParams = _GDIPlus_ParamInit(1) ;initialize an encoder parameter list and return $tagGDIPENCODERPARAMS structure
;    Local $tData = DllStructCreate("int Quality") ;create struct to set JPG quality setting
;    DllStructSetData($tData, "Quality", 100) ;quality 0-100 (0: lowest, 100: highest)
;    Local $pData = DllStructGetPtr($tData) ;get pointer from quality struct
;    _GDIPlus_ParamAdd($tParams, $GDIP_EPGQUALITY, 1, $GDIP_EPTLONG, $pData) ;add a value to an encoder parameter list

;    Local $gbmp = _GDIPlus_BitmapCreateFromHBITMAP($bmp)
;    _WinAPI_DeleteObject($bmp)

;    Local $gsbmp = _GDIPlus_ImageResize($gbmp, $w * $scale, $h * $scale)
    ;Local $ext = _GDIPlus_EncodersGetCLSID("PNG")
;    _GDIPlus_ImageSaveToFileEx($gsbmp, $outimage, $sImgCLSID)

;    _GDIPlus_BitmapDispose($gbmp)
;    _GDIPlus_BitmapDispose($gsbmp)
;  _GDIPlus_Shutdown()
;EndFunc

Thanks for any help you can give me!!!

Edited October 14, 2016 by LegitStack

[genius257]

I know it's not perfect but you might get some useful information from: Writing DPI-Aware Desktop and Win32 Applications

More specifically: Assessing DPI Compatibility

[RTFC]

I'm having a deja-lu

[LegitStack]

2 hours ago, RTFC said:

I'm having a deja-lu

Thanks RTFC!

this is what I came up with to fix the prob:

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#include <lib\applieddpi.au3>


Func Load_ScreenCapture_High_DPI_Check()
  $R = GetScale()
  if $R == 1 then
    ; should fix this to work with dual monitors. later.
  else
    #Region ;**** Directives created by AutoIt3Wrapper_GUI ****
    #AutoIt3Wrapper_Res_HiDpi=Y
    #EndRegion ;**** Directives created by AutoIt3Wrapper_GUI ****
    DllCall("User32.dll","bool","SetProcessDPIAware")
    ;(work around) first screencapture doesn't seem to work right, so take one and throw away.
    _ScreenCapture_Capture("",0,0,@DesktopWidth,@DesktopHeight)
  endif
EndFunc

Load_ScreenCapture_High_DPI_Check()

;;;;;;;AppliedDPI.au3


#include <Security.au3>


Func _GetAppliedDPI()
  Local $AppliedDPI = RegRead("HKEY_CURRENT_USER\Control Panel\Desktop\WindowMetrics", "AppliedDPI")
  return $AppliedDPI
EndFunc


Func GetScale()
  $applied = _GetAppliedDPI()
  if $applied == "" then
    return 1
  else
    return $applied / 96
  EndIf
EndFunc

 

 

[JennMaughan]

On 10/16/2016 at 2:36 PM, LegitStack said:

Thanks RTFC!

this is what I came up with to fix the prob:

expandcollapse popup

#include <lib\applieddpi.au3>


Func Load_ScreenCapture_High_DPI_Check()
  $R = GetScale()
  if $R == 1 then
    ; should fix this to work with dual monitors. later.
  else
    #Region ;**** Directives created by AutoIt3Wrapper_GUI ****
    #AutoIt3Wrapper_Res_HiDpi=Y
    #EndRegion ;**** Directives created by AutoIt3Wrapper_GUI ****
    DllCall("User32.dll","bool","SetProcessDPIAware")
    ;(work around) first screencapture doesn't seem to work right, so take one and throw away.
    _ScreenCapture_Capture("",0,0,@DesktopWidth,@DesktopHeight)
  endif
EndFunc

Load_ScreenCapture_High_DPI_Check()

;;;;;;;AppliedDPI.au3


#include <Security.au3>


Func _GetAppliedDPI()
  Local $AppliedDPI = RegRead("HKEY_CURRENT_USER\Control Panel\Desktop\WindowMetrics", "AppliedDPI")
  return $AppliedDPI
EndFunc


Func GetScale()
  $applied = _GetAppliedDPI()
  if $applied == "" then
    return 1
  else
    return $applied / 96
  EndIf
EndFunc

 

 

New to using computers with High Resolution screens...    and trying to get my scripts to adjust similar problems to this thread.  I'm having difficulty getting autoit to locate 

#include <lib\applieddpi.au3>

what file or location would I have it search for that?  thank you for entertaining a noob question... never had issues before  guessing the script itself isnt saved in the right location to find the file. 

 

 

[RTFC]

@JennMaughan: AFAIK, that's not a standard AutoIt include file, but probably something user LegitStack put together. You should be alright just copying only those functions to your own script(s), if you wish to use them.