GDI+ How to improve jpg‘s quality

[fenhanxue]

I want to replace the specified area of picture 1.jpg with picture 2.jpg.

my code is as follow:

#AutoIt3Wrapper_UseX64 = n
#include <GDIPlus.au3>




_GDIPlus_Startup()
Local $hBitmap = _GDIPlus_ImageLoadFromFile(@ScriptDir&'\1.jpg')
Local $hImage_replace = _GDIPlus_ImageLoadFromFile(@ScriptDir&'\2.jpg')

;set the quality 
Local $iJPGQual = 100
Local $sCLSID = _GDIPlus_EncodersGetCLSID("JPG")
Local $tParams = _GDIPlus_ParamInit(10)
Local $tData = DllStructCreate("int Quality")
DllStructSetData($tData, "Quality", $iJPGQual)
Local $pData = DllStructGetPtr($tData)
_GDIPlus_ParamAdd($tParams, $GDIP_EPGQUALITY, 1, $GDIP_EPTLONG, $pData)
Local $pParams = DllStructGetPtr($tParams)  
                    

Local $hGraphic = _GDIPlus_ImageGetGraphicsContext($hBitmap)
_GDIPlus_GraphicsDrawImageRect($hGraphic, $hImage_replace, 98, 98, 60, 60)

_GDIPlus_ImageSaveToFileEx($hBitmap, (@ScriptDir&'\out.jpg'), $sCLSID, $pParams)
                        
;Dispose
_GDIPlus_GraphicsDispose($hGraphic)
_GDIPlus_BitmapDispose($hImage_replace)                         
_GDIPlus_BitmapDispose($hBitmap)
_GDIPlus_Shutdown()

 

 

however, i find the out.jpg  's  quality  is not very good , can anyone help me ?

 

 

 

 

 

 

====================

this is  1.jpg

 

 

 

=======================

this is   2.jpg

[argumentum]

vectorize the raster. Good luck, as I don't know how.

I did not understand the question at first. The title is misleading.
I guess the amount of pixels to represent 2.jpg gives undesired results.
The only way is to have greater a resolution. More pixels.

Edited November 25, 2017 by argumentum

[junkew]

I think in the encoding parameters you have to tweak to get your desired result. What happens when you save it to gif, png, tiff, bmp?

check with irfanview your imageproperties if your compression quality is indeed 100 as you are trying or that it has a different quality value

not sure if this can help http://www.mediachance.com/digicam/jpgq.htm it explains a little more