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VB 5/6-Tipp 0680: Intensität der Farbkanäle CMYK mit GDI+ darstellen

 von Frank Schüler

Schwierigkeitsgrad:

Verwendete API-Aufrufe: GdipCreateBitmapFromGraphics, GdipCreateFromHDC, GdipCreateImageAttributes, GdipDeleteGraphics, GdipDisposeImage, GdipDisposeImageAttributes, GdipDrawImageRect, GdipDrawImageRectRect, GdipGetImageDimension, GdipGetImageGraphicsContext, GdipLoadImageFromFile, GdipSetImageAttributesOutputChannel, GdiplusShutdown, GdiplusStartup

Download: Download des Beispielprojektes [5,2 KB]

'Dieser Quellcode stammt von http://www.activevb.de
'und kann frei verwendet werden. Für eventuelle Schäden
'wird nicht gehaftet.

'Um Fehler oder Fragen zu klären, nutzen Sie bitte unser Forum.
'Ansonsten viel Spaß und Erfolg mit diesem Source!

'------- Anfang Projektdatei GDIPlusOutputChannel.vbp -------
' Die Komponente 'Microsoft Common Dialog Control 6.0 (SP3) (comdlg32.ocx)' wird benötigt.

'--- Anfang Formular "frmGDIPlusOutputChannel" alias frmGDIPlusOutputChannel.frm  ---
' Steuerelement: Bildfeld-Steuerelement "picChannel" (Index von 0 bis 0)
' Steuerelement: Schaltfläche "cmdLoadPicture"
' Steuerelement: Standarddialog-Steuerelement "CommonDialog1"

Option Explicit

' ----==== GDI+ Konstenten ====----
Private Const GdiPlusVersion As Long = 1&

' ----==== GDI+ Typen ====----
Private Type GDIPlusStartupInput
    GdiPlusVersion As Long
    DebugEventCallback As Long
    SuppressBackgroundThread As Long
    SuppressExternalCodecs As Long
End Type

Private Type GdiplusStartupOutput
    NotificationHook As Long
    NotificationUnhook As Long
End Type

' ----==== GDI+ Enumerationen ====----
Private Enum ColorAdjustType
    ColorAdjustTypeDefault = 0
    ColorAdjustTypeBitmap = 1
    ColorAdjustTypeBrush = 2
    ColorAdjustTypePen = 3
    ColorAdjustTypeText = 4
    ColorAdjustTypeCount = 5
    ColorAdjustTypeAny = 6
End Enum

Private Enum ColorChannelFlags
    ColorChannelFlagsC = 0
    ColorChannelFlagsM = 1
    ColorChannelFlagsY = 2
    ColorChannelFlagsK = 3
    ColorChannelFlagsLast = 4
End Enum

'GDI+ Status
Private Enum Status
    OK = 0
    GenericError = 1
    InvalidParameter = 2
    OutOfMemory = 3
    ObjectBusy = 4
    InsufficientBuffer = 5
    NotImplemented = 6
    Win32Error = 7
    WrongState = 8
    Aborted = 9
    FileNotFound = 10
    ValueOverflow = 11
    AccessDenied = 12
    UnknownImageFormat = 13
    FontFamilyNotFound = 14
    FontStyleNotFound = 15
    NotTrueTypeFont = 16
    UnsupportedGdiplusVersion = 17
    GdiplusNotInitialized = 18
    PropertyNotFound = 19
    PropertyNotSupported = 20
    ProfileNotFound = 21
End Enum

Private Enum Unit
    UnitWorld = 0
    UnitDisplay = 1
    UnitPixel = 2
    UnitPoint = 3
    UnitInch = 4
    UnitDocument = 5
    UnitMillimeter = 6
End Enum

' ----==== GDI+ API Deklarationen ====----
Private Declare Function GdipCreateBitmapFromGraphics Lib "gdiplus" _
    (ByVal Width As Long, ByVal Height As Long, _
    ByVal target As Long, ByRef bitmap As Long) As Status

Private Declare Function GdipCreateFromHDC Lib "gdiplus" _
    (ByVal hdc As Long, ByRef graphics As Long) As Status

Private Declare Function GdipCreateImageAttributes Lib "gdiplus" _
    (ByRef imageattr As Long) As Status

Private Declare Function GdipDeleteGraphics Lib "gdiplus" _
    (ByVal graphics As Long) As Status

Private Declare Function GdipDisposeImage Lib "gdiplus" _
    (ByVal image As Long) As Status

Private Declare Function GdipDisposeImageAttributes Lib "gdiplus" _
    (ByVal imageattr As Long) As Status

Private Declare Function GdipDrawImageRect Lib "gdiplus" _
    (ByVal graphics As Long, ByVal image As Long, _
    ByVal X As Single, ByVal Y As Single, _
    ByVal Width As Single, ByVal Height As Single) As Status

Private Declare Function GdipDrawImageRectRect Lib "gdiplus" _
    (ByVal graphics As Long, ByVal image As Long, _
    ByVal dstx As Single, ByVal dsty As Single, _
    ByVal dstwidth As Single, ByVal dstheight As Single, _
    ByVal srcx As Single, ByVal srcy As Single, _
    ByVal srcwidth As Single, ByVal srcheight As Single, _
    ByVal srcUnit As Unit, _
    Optional ByVal imageAttributes As Long = 0, _
    Optional ByVal callback As Long = 0, _
    Optional ByVal callbackData As Long = 0) As Status

Private Declare Function GdipGetImageDimension Lib "gdiplus" _
    (ByVal image As Long, ByRef Width As Single, _
    ByRef Height As Single) As Status

Private Declare Function GdipGetImageGraphicsContext Lib "gdiplus" _
    (ByVal image As Long, ByRef graphics As Long) As Status

Private Declare Function GdipSetImageAttributesOutputChannel _
    Lib "gdiplus" (ByVal imageattr As Long, _
    ByVal ColorAdjust As ColorAdjustType, _
    ByVal enableFlag As Boolean, _
    ByVal channelFlags As ColorChannelFlags) As Status

Private Declare Function GdipLoadImageFromFile Lib "gdiplus" _
    (ByVal FileName As Long, ByRef image As Long) As Status

Private Declare Function GdiplusShutdown Lib "gdiplus" _
    (ByVal token As Long) As Status

Private Declare Function GdiplusStartup Lib "gdiplus" _
    (ByRef token As Long, ByRef lpInput As GDIPlusStartupInput, _
    ByRef lpOutput As GdiplusStartupOutput) As Status

' ----==== Variablen ====----
Dim GdipToken As Long
Dim GdipInitialized As Boolean

'------------------------------------------------------
' Funktion     : DrawImageChannelFromFile
' Beschreibung : Lädt ein Bilddatei per GDI+ vom Datenträger
'                und zeigt die Intensität des
'                angegeben Farbkanales an
' Übergabewert : sFileName = Pfad\Dateiname der Bilddatei
'                lDrawHdc = HDC vom Objekt in dem gezeichnet
'                           werden soll
'                eChannelFlag = Enum ColorChannelFlags
'------------------------------------------------------
Private Sub DrawImageChannelFromFile(ByVal sFileName As String, _
    ByVal lDrawHdc As Long, ByVal eChannelFlag As ColorChannelFlags)
    
    Dim lBitmap As Long
    Dim lBitmap2 As Long
    Dim lGraphics As Long
    Dim lGraphics2 As Long
    Dim lImgAttr As Long
    Dim sImageWidth As Single
    Dim sImageHeight As Single
    
    ' Erzeugt ein Graphicsobjekt
    ' vom Hdc -> lGraphics
    If Execute(GdipCreateFromHDC(lDrawHdc, _
    lGraphics)) = OK Then
        
        ' Laden der Bilddatei und erzeugen eines
        ' Bitmapobjekts sFileName -> lBitmap
        If Execute(GdipLoadImageFromFile(StrPtr(sFileName), _
        lBitmap)) = OK Then
            
            ' Ermitteln der Dimensionen des Bitmapobjekts
            Call Execute(GdipGetImageDimension(lBitmap, _
            sImageWidth, sImageHeight))
            
            ' Erzeugt ein ImageAttributesobjekt
            If Execute(GdipCreateImageAttributes( _
            lImgAttr)) = OK Then
                
                ' Setzen des OutputChannel für das
                ' ImageAttributesobjekt
                If Execute(GdipSetImageAttributesOutputChannel( _
                lImgAttr, ColorAdjustTypeDefault, _
                True, eChannelFlag)) = OK Then
                    
                    ' Erzeugt ein Graphicsobjekt vom
                    ' Bitmapobjekt lBitmap -> lGraphics2
                    If Execute(GdipGetImageGraphicsContext( _
                    lBitmap, lGraphics2)) = OK Then
                        
                        ' Erzeugt ein Bitmapobjekt vom
                        ' Graphicsobjekt lGraphics2 -> lBitmap2
                        If Execute(GdipCreateBitmapFromGraphics( _
                        sImageWidth, sImageHeight, lGraphics2, _
                        lBitmap2)) = OK Then
                            
                            ' Löschen von lGraphics2
                            Call Execute(GdipDeleteGraphics( _
                            lGraphics2))
                            
                            ' Erzeugt ein Graphicsobjekt vom
                            ' Bitmapobjekt
                            ' lBitmap2 -> lGraphics2
                            If Execute(GdipGetImageGraphicsContext( _
                            lBitmap2, lGraphics2)) = OK Then
                                
                                ' Zeichnet lBitmap in das
                                ' Graphicsobjekt lGraphics2 mit den
                                ' entsprechenden ImageAttributen
                                Call Execute(GdipDrawImageRectRect( _
                                lGraphics2, lBitmap, _
                                0, 0, sImageWidth, sImageHeight, _
                                0, 0, sImageWidth, sImageHeight, _
                                UnitPixel, lImgAttr))
                                
                                ' Löscht lGraphics2
                                Call Execute(GdipDeleteGraphics( _
                                lGraphics2))
                                
                                ' Löscht lBitmap
                                Call Execute(GdipDisposeImage( _
                                lBitmap))
                                
                                ' Zeichnet lBitmap2 in das
                                ' Graphicsobjektes lGraphics2
                                Call Execute(GdipDrawImageRect( _
                                lGraphics, lBitmap2, 0, 0, _
                                sImageWidth, sImageHeight))
                                
                                ' Löscht lBitmap2
                                Call Execute(GdipDisposeImage( _
                                lBitmap2))
                            End If
                        End If
                    End If
                End If
                
                ' Löscht lImgAttr
                Call Execute(GdipDisposeImageAttributes(lImgAttr))
            End If
        End If
        
        ' Löscht lGraphics
        Call Execute(GdipDeleteGraphics(lGraphics))
    End If
End Sub

'------------------------------------------------------
' Funktion     : DrawImageFromFile
' Beschreibung : Lädt ein Bilddatei per GDI+ vom Datenträger
' Übergabewert : sFileName = Pfad\Dateiname der Bilddatei
'                lDrawHdc = HDC vom Objekt in dem
'                           gezeichnet werden soll
'------------------------------------------------------
Private Sub DrawImageFromFile(ByVal sFileName As String, _
    ByVal lDrawHdc As Long)
    
    Dim lBitmap As Long
    Dim lGraphics As Long
    Dim sImageWidth As Single
    Dim sImageHeight As Single
    
    ' Erzeugen eines Graphicsobjektes
    ' vom Hdc -> lGraphics
    If Execute(GdipCreateFromHDC(lDrawHdc, _
    lGraphics)) = OK Then
        
        ' Laden der Bilddatei -> lBitmap
        If Execute(GdipLoadImageFromFile(StrPtr(sFileName), _
        lBitmap)) = OK Then
            
            ' Ermitteln der Dimensionen von lBitmap
            Call Execute(GdipGetImageDimension(lBitmap, _
            sImageWidth, sImageHeight))
            
            ' Zeichnet lBitmap in lGraphics
            Call Execute(GdipDrawImageRect(lGraphics, _
            lBitmap, 0, 0, sImageWidth, sImageHeight))
            
            ' Löscht lBitmap
            Call Execute(GdipDisposeImage(lBitmap))
        End If
        
        ' Löscht lGraphics
        Call Execute(GdipDeleteGraphics(lGraphics))
    End If
End Sub

'------------------------------------------------------
' Funktion     : Execute
' Beschreibung : Gibt im Fehlerfall die entsprechende
'                GDI+ Fehlermeldung aus
' Übergabewert : GDI+ Status
' Rückgabewert : GDI+ Status
'------------------------------------------------------
Private Function Execute(ByVal lReturn As Status) As Status
    Dim lCurErr As Status
    If lReturn = OK Then
        lCurErr = OK
    Else
        lCurErr = lReturn
        MsgBox GdiErrorString(lReturn) & " GDI+ Error:" _
        & lReturn, vbOKOnly, "GDI Error"
    End If
    Execute = lCurErr
End Function

'------------------------------------------------------
' Funktion     : GdiErrorString
' Beschreibung : Umwandlung der GDI+ Statuscodes in Stringcodes
' Übergabewert : GDI+ Status
' Rückgabewert : Fehlercode als String
'------------------------------------------------------
Private Function GdiErrorString(ByVal lError As Status) As String
    Dim s As String
    
    Select Case lError
    Case GenericError:              s = "Generic Error."
    Case InvalidParameter:          s = "Invalid Parameter."
    Case OutOfMemory:               s = "Out Of Memory."
    Case ObjectBusy:                s = "Object Busy."
    Case InsufficientBuffer:        s = "Insufficient Buffer."
    Case NotImplemented:            s = "Not Implemented."
    Case Win32Error:                s = "Win32 Error."
    Case WrongState:                s = "Wrong State."
    Case Aborted:                   s = "Aborted."
    Case FileNotFound:              s = "File Not Found."
    Case ValueOverflow:             s = "Value Overflow."
    Case AccessDenied:              s = "Access Denied."
    Case UnknownImageFormat:        s = "Unknown Image Format."
    Case FontFamilyNotFound:        s = "FontFamily Not Found."
    Case FontStyleNotFound:         s = "FontStyle Not Found."
    Case NotTrueTypeFont:           s = "Not TrueType Font."
    Case UnsupportedGdiplusVersion: s = "Unsupported Gdiplus Version."
    Case GdiplusNotInitialized:     s = "Gdiplus Not Initialized."
    Case PropertyNotFound:          s = "Property Not Found."
    Case PropertyNotSupported:      s = "Property Not Supported."
    Case Else:                      s = "Unknown GDI+ Error."
    End Select
    
    GdiErrorString = s
End Function

'------------------------------------------------------
' Funktion     : StartUpGDIPlus
' Beschreibung : Initialisiert GDI+ Instanz
' Übergabewert : GDI+ Version
' Rückgabewert : GDI+ Status
'------------------------------------------------------
Private Function StartUpGDIPlus(ByVal GdipVersion As Long) As Status
    ' Initialisieren der GDI+ Instanz
    Dim GdipStartupInput As GDIPlusStartupInput
    Dim GdipStartupOutput As GdiplusStartupOutput
    
    GdipStartupInput.GdiPlusVersion = GdipVersion
    StartUpGDIPlus = GdiplusStartup(GdipToken, _
    GdipStartupInput, GdipStartupOutput)
End Function

'------------------------------------------------------
' Funktion     : ShutdownGDIPlus
' Beschreibung : Beendet die GDI+ Instanz
' Rückgabewert : GDI+ Status
'------------------------------------------------------
Private Function ShutdownGDIPlus() As Status
    ' Beendet GDI+ Instanz
    ShutdownGDIPlus = GdiplusShutdown(GdipToken)
End Function

Private Sub cmdLoadPicture_Click()
    
    Dim z As Long
    
    ' Fehlerbehandlung
    On Error Goto errorhandler
    
    ' ist GDI+ initialisiert
    If GdipInitialized = True Then
        
        ' Dialogparameter setzen
        With CommonDialog1
            .Filter = _
            "Images Files (*.bmp;*.gif;*.jpg;*.png;*.tif)" _
            & "|*.bmp;*.gif;*.jpg;*.png;*.tif"
            .CancelError = True
            .ShowOpen
        End With
        
        ' Inhalt in PictureBoxen löschen
        For z = 0 To 4
            picChannel(z).Cls
        Next z
        
        ' Zeichnet das Original Bild
        Call DrawImageFromFile(CommonDialog1.FileName, _
        picChannel(0).hdc)
        
        ' Zeichnet das Original Bild und zeigt die
        ' Intensität vom Farbkanal Cyan in Graustufen
        Call DrawImageChannelFromFile(CommonDialog1.FileName, _
        picChannel(1).hdc, ColorChannelFlagsC)
        
        ' Zeichnet das Original Bild und zeigt die
        ' Intensität vom Farbkanal Magenta in Graustufen
        Call DrawImageChannelFromFile(CommonDialog1.FileName, _
        picChannel(2).hdc, ColorChannelFlagsM)
        
        ' Zeichnet das Original Bild und zeigt die
        ' Intensität vom Farbkanal Yellow in Graustufen
        Call DrawImageChannelFromFile(CommonDialog1.FileName, _
        picChannel(3).hdc, ColorChannelFlagsY)
        
        ' Zeichnet das Original Bild und zeigt die
        ' Intensität vom Farbkanal Black in Graustufen
        Call DrawImageChannelFromFile(CommonDialog1.FileName, _
        picChannel(4).hdc, ColorChannelFlagsK)
        
        ' Refresh der PictureBoxen
        For z = 0 To 4
            picChannel(z).Refresh
        Next z
        
    End If
    Exit Sub
errorhandler:
End Sub

Private Sub Form_Load()
    
    Dim z As Long
    
    GdipInitialized = False
    
    ' Form Parameter setzen
    With Me
        .ScaleMode = vbTwips
        .Height = 7020
        .Width = 9360
    End With
    
    ' Button Parameter setzen
    With cmdLoadPicture
        .Move 60, 60, 1700, 375
        .Caption = "Load Picture"
    End With
    
    ' PicturBox Parameter setzen
    With picChannel(0)
        .Move 60, 60 + cmdLoadPicture.Top _
        + cmdLoadPicture.Height, 3000, 3000
        .AutoRedraw = True
    End With
    
    ' weitere PicturBoxen laden
    For z = 1 To 4
        Load picChannel(z)
        picChannel(z).Visible = True
    Next z
    
    ' neue PictureBoxen positionieren
    picChannel(1).Move 60 + picChannel(0).Left _
    + picChannel(0).Width, picChannel(0).Top
    
    picChannel(2).Move 60 + picChannel(1).Left _
    + picChannel(1).Width, picChannel(0).Top
    
    picChannel(3).Move picChannel(1).Left, _
    60 + picChannel(1).Top + picChannel(1).Height
    
    picChannel(4).Move picChannel(2).Left, _
    60 + picChannel(2).Top + picChannel(2).Height
    
    ' Initialisieren von GDI+
    If Execute(StartUpGDIPlus(GdiPlusVersion)) = OK Then
        GdipInitialized = True
    Else
        ' Initialisierung fehlgeschlagen
        MsgBox "GDI+ not inizialized.", vbOKOnly, "GDI Error"
    End If
End Sub

Private Sub Form_Unload(Cancel As Integer)
    
    ' ist GDI+ initialisiert
    If GdipInitialized = True Then
        
        ' GDI+ beenden
        Call Execute(ShutdownGDIPlus)
    End If
End Sub
'--- Ende Formular "frmGDIPlusOutputChannel" alias frmGDIPlusOutputChannel.frm  ---
'-------- Ende Projektdatei GDIPlusOutputChannel.vbp --------