，这就使得数字成为它们之间沟通道桥梁。因此就可以将文本藏入图片中。 这里用Visual Basic 6.0实现，首先我们将文字转化为数字，再将图片中的每个点的RGB值取出，将数字每三个分别与R值，G值，B值相加或

相减，接着把RGB值还原为图片中的点，至此我们已经将文本藏入图片。要取出文本怎么办呢？我们可以把源图片与目标图片进行对比，将到的

差值转化为文本，就实现了文本的还原。

具体作法：先建立窗体文件frmPictureText.frm和模块文件modPictureText.bas 模块文件： Public Declare Function GetObject Lib "gdi32" Alias "GetObjectA" (ByVal _ hObject As Long, ByVal nCount As Long, lpObject As Any) As Long '用于获得图片的象素

Public Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, ByVal x _ As Long, ByVal y As Long) As Long '用于获得图片指定点的RGB值 Public Type BITMAP bmType As Long bmWidth As Long bmHeight As Long bmWidthBytes As Long bmPlanes As Integer bmBitsPixel As Integer bmBits As Long End Type

Function HexDec(Number As String) As Integer '将十六进制转化为十进制 Dim n As Integer, dec As String, tmp As Integer For n = 1 To Len(Number) dec = Mid(Number, n, 1) If Asc(dec) >= 65 Then dec = UCase(dec) dec = Format(Asc(dec) - 55) End If tmp = Val(dec) * 16 ^ (Len(Number) - n) HexDec = HexDec + tmp Next n End Function 窗体文件：建立两个图片框:picSource用于显示源图片，picObject用于显示目标图片， 建立两个文本框：txtSource用于显示源文本，txtObject用于显示还原的文本，并设置为各多行显示，建立两个命令按钮：cmdTextToPicture

用于把文本藏入图片，cmdPictureToText用于还原文本。 Private Sub Form_Load() picSource.AutoRedraw = True: picObject.AutoRedraw = True picSource.AutoSize = True: picObject.AutoSize = True picSource.Picture = LoadPicture("c:\test.bmp") picObject.Height = picSource.Height '设置目标图片框的Height和 picObject.Width = picSource.Width 'Width属性与源图片相同,保证 '目标图片的大小和源文件相同 End Sub

Private Sub cmdTextToPicture_Click() Dim numX As Integer, chrTmp As String, numTmp As Integer, numY As Integer, _ word As String Dim souPixel As BITMAP, souTop As Integer, souLeft As Integer Dim souColor As Long, souGetcolor As String, numN As Integer Dim tmpWord As String, numDifRed As Integer, numDifGreen As Integer, _ numDifBlue As Integer Dim newRed As Integer, newGreen As Integer, newBlue As Integer

On Error Resume Next Open "c:\temp1.txt" For Output As #1 '将文本转化为数字,并存入文件 For numX = 1 To Len(txtSource.Text) numTmp = Asc(Mid(txtSource.Text, numX, 1)) chrTmp = Format(numTmp) If numTmp >= 0 Then chrTmp = "+" & chrTmp For numY = 1 To Len(chrTmp) word = Format(Asc(Mid(chrTmp, numY, 1))) Print #1, word; Next numY Next numX Close #1

Open "c:\temp1.txt" For Input As #2 GetObject picSource.Picture.Handle, Len(souPixel), souPixel picObject.Picture = Nothing: picObject.Cls For souTop = 0 To souPixel.bmHeight - 1 For souLeft = 0 To souPixel.bmWidth - 1 '取出图片各点的RGB值 souColor = GetPixel(picSource.hdc, souLeft, souTop) souGetcolor = Hex(souColor) numN = 6 - Len(souGetcolor) souGetcolor = String(numN, "0") & souGetcolor '取出三个数字 If Not (EOF(2)) Then tmpWord = Input(3, #2) numDifRed = Val(Left(tmpWord, 1)) numDifGreen = Val(Mid(tmpWord, 2, 1)) numDifBlue = Val(Right(tmpWord, 1)) End If '把数字与R值,G值,B值相加或相减 newRed = HexDec(Right(souGetcolor, 2)) - numDifRed If newRed < 0 Then newRed = HexDec(Right(getcolor, 2)) + numDifRed newGreen = HexDec(Mid(souGetcolor, 3, 2)) - numDifGreen If newGreen < 0 Then newGreen = HexDec(Mid(souGetcolor, 3, 2)) + numDifGreen newBlue = HexDec(Left(souGetcolor, 2)) - numDifBlue If newBlue < 0 Then newBlue = HexDec(Left(souGetcolor, 2)) + numDifBlue numDifRed = 0: numDifGreen = 0: numDifBlue = 0 DoEvents '形成目标图片 picObject.PSet (souLeft, souTop), RGB(newRed, newGreen, newBlue) Next souLeft Next souTop Close #2 SavePicture picObject.Image, "c:\object.bmp" picObject.Picture = LoadPicture("c:\object.bmp") End Sub

Private Sub cmdPictureToText_Click() Dim Pixel As BITMAP Dim souTop As Integer, souLeft As Integer Dim souColor As Long, objColor As Long, souGetcolor As String, _ objGetcolor As String Dim souRed As Integer, souGreen As Integer, souBlue As Integer Dim objRed As Integer, objGreen As Integer, objBlue As Integer Dim souN As Integer, objN As Integer Dim numDifRed As Integer, chrDifRed As String Dim numDifGreen As Integer, chrDifGreen As String Dim numDifBlue As Integer, chrDifBlue As String Dim Difference As String, numTmp As Integer, chrTmp As String, tmpWord As _ String, word As String

On Error Resume Next GetObject picSource.Picture.Handle, Len(Pixel), Pixel '获取图片的象素 Kill "c:\temp2.txt" '如果存在"temp2.txt"文件,则将它清除 Open "c:\temp2.txt" For Append As #3 For souTop = 0 To Pixel.bmHeight - 1 For souLeft = 0 To Pixel.bmWidth - 1 '获得源图片各点的RGB值 souColor = GetPixel(picSource.hdc, souLeft, souTop) souGetcolor = Hex(souColor) souN = 6 - Len(souGetcolor) souGetcolor = String(souN, "0") & souGetcolor souRed = HexDec(Right(souGetcolor, 2)) '转化为Red,Green,Blue的值 souGreen = HexDec(Mid(souGetcolor, 3, 2)) souBlue = HexDec(Left(souGetcolor, 2)) '获得目标图片各点的RGB值 objColor = GetPixel(picObject.hdc, souLeft, souTop) objGetcolor = Hex(objColor) objN = 6 - Len(objGetcolor) objGetcolor = String(objN, "0") & objGetcolor objRed = HexDec(Right(objGetcolor, 2)) objGreen = HexDec(Mid(objGetcolor, 3, 2)) objBlue = HexDec(Left(objGetcolor, 2)) numDifRed = souRed - objRed '将差值存入文件 chrDifRed = Format(numDifRed) If numDifRed < 0 Then chrDifRed = Format(objRed - souRed) numDifGreen = souGreen - objGreen chrDifGreen = Format(numDifGreen) If numDifGreen < 0 Then chrDifGreen = Format(objGreen - souGreen) numDifBlue = souBlue - objBlue chrDifBlue = Format(numDifBlue) If numDifBlue < 0 Then chrDifBlue = Format(objBlue - souBlue) Difference = chrDifRed & chrDifGreen & chrDifBlue Print #3, Difference; Next souLeft Next souTop Close #3

Open "c:\temp2.txt" For Input As #4 '从文件还原文字 Do While Not EOF(4) numTmp = Input(2, #4) chrTmp = Chr(Val(numTmp)) If (Len(tmpWord) > 1) And (chrTmp = "+" Or chrTmp = "-") Then word = Chr(Val(tmpWord)) txtobject.Text = txtobject.Text & word tmpWord = "" End If tmpWord = tmpWord & chrTmp Loop txtobject.Text = txtobject.Text & Chr(Val(tmpWord)) Close #4 End Sub