Bonjour,
J'essaie (depuis un bon moment) de faire un programme de stéganographie (cacher du texte dans une image) qui coderait les caractères sur le bit le - significatif.  Le problème, c'est que le texte décrypté contient des erreurs:

END-USER LICENSE AGREEMENT FOR MICROSOFT SOFTWARE

IMPORTANT-READ CAREFULLY: This Microsoft End-User License Agreement (''EULA'') is a legal agreement between you (either an individual or a single entity) and Microsoft Corporation for the Microsoft software product(s) accompanying this EULA, which include(s) computer software and may include "online" or electronic documentation, associated media, and printed materials (''SOFTWARE PRODUCT''). By installing, copying, or otherwise using the SOFTWARE PRODUCT or any UPDATES (as defined below), you agree to be bound by the terms of this EULA. If you do not agree to the terms of this EULA, do not install, copy, or otherwise use the SOFTWARE PRODUCT; you may, however, return it to your place of purchase for a full refund. In addition, by installing, copying, or otherwise using any updates or other components of the SOFTWARE PRODUCT that you receive separately as part of the SOFTWARE PRODUCT (''UPDATES''), you agree to be bound by any additional license terms that accompany such UPDATES. If you do not agree to the additional license terms that accompany such UPDATES, you may not install, copy, or otherwise use such UPDATES.

devient:

"END-USER LICENSE AGREEMENT FOR MICROSOFT SOFTWARE

IMPORTANT-READ CAREFULLY: This Moÿ�2;osoft End-User License Agreement (''EULA'') is a legal agreement between you (either ÿ individual or a single entity) and Microsoft Corporation for the Microsoft software ÿ/duct(s) accompanying this EULA, which include(s) computer software and may include ""oÿ�4;ine"" or electronic documentation, associated media, and printed materials (''SOFTWARERODUCT''). By installing, copying, or otherwise using the SOFTWARE PRODUCT or any UPDOÿ�5;S (as defined below), you agree to be bound by the terms of this EULA. If you do not!ÿ�3;ree to the terms of this EULA, do not install, copy, or otherwise use the SOFTWARE PRÿUCT; you may, however, return it to your place of purchase for a full refund. In addiwÿ�F;n, by installing, copying, or otherwise using any updates or other components of the ÿ�1;FTWARE PRODUCT that you receive separately as part of the SOFTWARE PRODUCT (''UPDATES?ÿ), you agree to be bound by any additional license terms that accompany such UPDATES.#ÿ�6; you do not agree to the additional license terms that accompany such UPDATES, you manot install, copy, or otherwise use such UPDATES.
Est-ce que quelqu'un sait ce qui peut donner ce genre d'erreur
Merci d'avance
Vautour32

Bonjour et merci d'avoir répondu si vite,

"ET puis les caractères parasites sont du coté obscur de l'UNICODE !! Sans doute un bit qui déborde et fait basculer un code ASCII sur une plage UNICODE"
Ca, c'est pas possible: les code de caractères sont codés dans un nombre binaire de 8 bits, ça ne pourra donc jamais dépasser 255.
Voici mon code:

Private Sub Code_image(X As Long)
CX = X

For CY = 0 To Picture1.Height Step Screen.TwipsPerPixelY

            Color = Picture1.Point(CX, CY)
            DecomposeRGB (Color) 'Decompose un code couleur en ses 3 compsantes RGB, dont il assigne les valeurs aux variable publique lRed, LGreen et LBlue
            
            If ctrInByte < 7 Then
            ctrInByte = ctrInByte + 1
            Else
            ctrInByte = 0
            ctrOutByte = ctrOutByte + 1
            End If
            If ctrOutByte < UBound(tPassword) Then lRed = CByte(bitsTOdec(Mid$(DecToBits(CLng(lRed)), 9, 7) & Mid$(tPassword(ctrOutByte), ctrInByte + 1, 1)))
           
            If ctrInByte < 7 Then
            ctrInByte = ctrInByte + 1
            Else
            ctrInByte = 0
            ctrOutByte = ctrOutByte + 1
            End If
            If ctrOutByte < UBound(tPassword) Then lGreen = CByte(bitsTOdec(Mid$(DecToBits(CLng(lGreen)), 9, 7) & Mid$(tPassword(ctrOutByte), ctrInByte + 1, 1)))
           
            If ctrInByte < 7 Then
            ctrInByte = ctrInByte + 1
            Else
            ctrInByte = 0
            ctrOutByte = ctrOutByte + 1
            End If
            If ctrOutByte < UBound(tPassword) Then lBlue = CByte(bitsTOdec(Mid$(DecToBits(CLng(lBlue)), 9, 7) & Mid$(tPassword(ctrOutByte), ctrInByte + 1, 1)))
           
            Color = RGB(lRed, lGreen, lBlue)
            Picture2.PSet (CX, CY), Color

Next CY

End Sub
'****
Public Sub DeCode_image(X As Long)
CX = X
Dim tmp As String
For CY = 0 To Picture1.Height Step Screen.TwipsPerPixelY

            Color = Picture1.Point(CX, CY)
            DecomposeRGB (Color)

            If ctrInByte < 7 Then
            ctrInByte = ctrInByte + 1
            Else
            ctrInByte = 0
            Text1.Text = Text1.Text & Chr$(bitsTOdec(tmp))
            tmp = ""
            ctrOutByte = ctrOutByte + 1
            End If
            If ctrOutByte < UBound(tPassword) Then tmp = tmp & Right$(DecToBits(lRed), 1)
            If ctrInByte < 7 Then
            ctrInByte = ctrInByte + 1
            Else
            ctrInByte = 0
            Text1.Text = Text1.Text & Chr$(bitsTOdec(tmp))
            tmp = ""
            ctrOutByte = ctrOutByte + 1
            End If
            If ctrOutByte < UBound(tPassword) Then tmp = tmp & Right$(DecToBits(lGreen), 1)
            If ctrInByte < 7 Then
            ctrInByte = ctrInByte + 1
            Else
            ctrInByte = 0
            Me.Caption = tmp
            Text1.Text = Text1.Text & Chr$(bitsTOdec(tmp))
            tmp = ""
            ctrOutByte = ctrOutByte + 1
            End If
           
            If ctrOutByte < UBound(tPassword) Then tmp = tmp & Right$(DecToBits(lBlue), 1)
            DoEvents
Next CY

End Sub
Bonne lecture et merci encore.
Vautour32