11/06/21 4:44
Pino1946
Buongiorno Carlo,
allora, non ho molto perchè, come dicevo, mi sono appena interessato a GdiPlus e ho scaricato (e buttato) diverso materiale perchè non ci ho capito un'acca (... colpa mia, è chiaro !).
Quello che al momento ho:
1 - stretch (e simili) ... che ho capito come funziona, ma il risultato non è soddisfacente (al riguardo dell'OCR),
StretchBlt Picture1.hdc, 0, 0, Picture1.ScaleWidth, Picture1.ScaleHeight, picDc, 0, 0, picWidth, picHeight, vbSrcCopy
2 - il codice che allego (trovato online) che non ho capito bene come funzioni:
_____________________________________________________
Private Type GUID
Data1 As Long
Data2 As Integer
Data3 As Integer
Data4(0 To 7) As Byte
End Type
Private Type GdiplusStartupInput
GdiplusVersion As Long
DebugEventCallback As Long
SuppressBackgroundThread As Long
SuppressExternalCodecs As Long
End Type
Private Type EncoderParameter
GUID As GUID
NumberOfValues As Long
type As Long
Value As Long
End Type
Private Type EncoderParameters
Count As Long
Parameter As EncoderParameter
End Type
Private Declare Function GdiplusStartup Lib "GDIPlus" (token As Long, inputbuf As GdiplusStartupInput, Optional ByVal outputbuf As Long = 0) As Long
Private Declare Function GdiplusShutdown Lib "GDIPlus" (ByVal token As Long) As Long
Private Declare Function GdipCreateBitmapFromHBITMAP Lib "GDIPlus" (ByVal hbm As Long, ByVal hpal As Long, Bitmap As Long) As Long
Private Declare Function GdipDisposeImage Lib "GDIPlus" (ByVal Image As Long) As Long
Private Declare Function GdipSaveImageToFile Lib "GDIPlus" (ByVal Image As Long, ByVal filename As Long, clsidEncoder As GUID, encoderParams As Any) As Long
Private Declare Function CLSIDFromString Lib "ole32" (ByVal str As Long, id As GUID) As Long
Public Sub SaveJPG(ByVal pict As StdPicture, ByVal filename As String, Optional ByVal Quality As Byte = 100) ' ----==== SaveJPG ====----
Dim tSI As GdiplusStartupInput
Dim lRes As Long
Dim lGDIP As Long
Dim lBitmap As Long
tSI.GdiplusVersion = 1 ' Initialize GDI+
lRes = GdiplusStartup(lGDIP, tSI)
If lRes = 0 Then
lRes = GdipCreateBitmapFromHBITMAP(pict.Handle, 0, lBitmap) ' Create the GDI+ bitmap from the image handle
If lRes = 0 Then
Dim tJpgEncoder As GUID
Dim tParams As EncoderParameters
CLSIDFromString StrPtr("{557CF401-1A04-11D3-9A73-0000F81EF32E}", tJpgEncoder ' Initialize the encoder GUID
tParams.Count = 1 ' Initialize the encoder parameters
With tParams.Parameter ' Quality
CLSIDFromString StrPtr("{1D5BE4B5-FA4A-452D-9CDD-5DB35105E7EB}", .GUID ' Set the Quality GUID
.NumberOfValues = 1
.type = 4
.Value = VarPtr(Quality)
End With
lRes = GdipSaveImageToFile(lBitmap, StrPtr(filename), tJpgEncoder, tParams) ' Salva
GdipDisposeImage lBitmap ' Destroy the bitmap
End If
GdiplusShutdown lGDIP ' Shutdown GDI+
End If
If lRes Then
Err.Raise 5, , "Cannot save the image. GDI+ Error:" & lRes
End If
End Sub
Private Sub Form_Load()
Call SaveJPG(StdPicture, "c:\Prova.bmp", 100)
End Sub
_____________________________________________________
Premetto che, quello che mi ha colpito, è la frase "Ho risolto usando una classe della gdiplus. Quindi salvo l'immagine in formato jpg impostando nel comando anche i DPI che nel mio caso sono 300 e 300", postato da "untipo".
Auguro una buona giornata
allora, non ho molto perchè, come dicevo, mi sono appena interessato a GdiPlus e ho scaricato (e buttato) diverso materiale perchè non ci ho capito un'acca (... colpa mia, è chiaro !).
Quello che al momento ho:
1 - stretch (e simili) ... che ho capito come funziona, ma il risultato non è soddisfacente (al riguardo dell'OCR),
StretchBlt Picture1.hdc, 0, 0, Picture1.ScaleWidth, Picture1.ScaleHeight, picDc, 0, 0, picWidth, picHeight, vbSrcCopy
2 - il codice che allego (trovato online) che non ho capito bene come funzioni:
_____________________________________________________
Private Type GUID
Data1 As Long
Data2 As Integer
Data3 As Integer
Data4(0 To 7) As Byte
End Type
Private Type GdiplusStartupInput
GdiplusVersion As Long
DebugEventCallback As Long
SuppressBackgroundThread As Long
SuppressExternalCodecs As Long
End Type
Private Type EncoderParameter
GUID As GUID
NumberOfValues As Long
type As Long
Value As Long
End Type
Private Type EncoderParameters
Count As Long
Parameter As EncoderParameter
End Type
Private Declare Function GdiplusStartup Lib "GDIPlus" (token As Long, inputbuf As GdiplusStartupInput, Optional ByVal outputbuf As Long = 0) As Long
Private Declare Function GdiplusShutdown Lib "GDIPlus" (ByVal token As Long) As Long
Private Declare Function GdipCreateBitmapFromHBITMAP Lib "GDIPlus" (ByVal hbm As Long, ByVal hpal As Long, Bitmap As Long) As Long
Private Declare Function GdipDisposeImage Lib "GDIPlus" (ByVal Image As Long) As Long
Private Declare Function GdipSaveImageToFile Lib "GDIPlus" (ByVal Image As Long, ByVal filename As Long, clsidEncoder As GUID, encoderParams As Any) As Long
Private Declare Function CLSIDFromString Lib "ole32" (ByVal str As Long, id As GUID) As Long
Public Sub SaveJPG(ByVal pict As StdPicture, ByVal filename As String, Optional ByVal Quality As Byte = 100) ' ----==== SaveJPG ====----
Dim tSI As GdiplusStartupInput
Dim lRes As Long
Dim lGDIP As Long
Dim lBitmap As Long
tSI.GdiplusVersion = 1 ' Initialize GDI+
lRes = GdiplusStartup(lGDIP, tSI)
If lRes = 0 Then
lRes = GdipCreateBitmapFromHBITMAP(pict.Handle, 0, lBitmap) ' Create the GDI+ bitmap from the image handle
If lRes = 0 Then
Dim tJpgEncoder As GUID
Dim tParams As EncoderParameters
CLSIDFromString StrPtr("{557CF401-1A04-11D3-9A73-0000F81EF32E}", tJpgEncoder ' Initialize the encoder GUID
tParams.Count = 1 ' Initialize the encoder parameters
With tParams.Parameter ' Quality
CLSIDFromString StrPtr("{1D5BE4B5-FA4A-452D-9CDD-5DB35105E7EB}", .GUID ' Set the Quality GUID
.NumberOfValues = 1
.type = 4
.Value = VarPtr(Quality)
End With
lRes = GdipSaveImageToFile(lBitmap, StrPtr(filename), tJpgEncoder, tParams) ' Salva
GdipDisposeImage lBitmap ' Destroy the bitmap
End If
GdiplusShutdown lGDIP ' Shutdown GDI+
End If
If lRes Then
Err.Raise 5, , "Cannot save the image. GDI+ Error:" & lRes
End If
End Sub
Private Sub Form_Load()
Call SaveJPG(StdPicture, "c:\Prova.bmp", 100)
End Sub
_____________________________________________________
Premetto che, quello che mi ha colpito, è la frase "Ho risolto usando una classe della gdiplus. Quindi salvo l'immagine in formato jpg impostando nel comando anche i DPI che nel mio caso sono 300 e 300", postato da "untipo".
Auguro una buona giornata
aaa