如何获知页面上的图象的实际尺寸？(2)

Set fso = CreateObject("Scripting.FileSystemObject")
Set ts = fso.OpenTextFile(Server.MapPath("/" & fichero), 1)
s = Right(ts.Read(24), 8)
HW(0) = HexToDec(HexAt(s,3) & HexAt(s,4))
HW(1) = HexToDec(HexAt(s,7) & HexAt(s,8))
ts.Close
ReadPNG = HW
End Function

Function ReadGIF(fichero)
Dim fso, ts, s, HW, nbytes
HW = Array("","")
Set fso = CreateObject("Scripting.FileSystemObject")
Set ts = fso.OpenTextFile(Server.MapPath("/" & fichero), 1)
s = Right(ts.Read(10), 4)
HW(0) = HexToDec(HexAt(s,2) & HexAt(s,1))
HW(1) = HexToDec(HexAt(s,4) & HexAt(s,3))
ts.Close
ReadGIF = HW
End Function


Function ReadWMF(fichero)
Dim fso, ts, s, HW, nbytes
HW = Array("","")
Set fso = CreateObject("Scripting.FileSystemObject")
Set ts = fso.OpenTextFile(Server.MapPath("/" & fichero), 1)
s = Right(ts.Read(14), 4)
HW(0) = HexToDec(HexAt(s,2) & HexAt(s,1))
HW(1) = HexToDec(HexAt(s,4) & HexAt(s,3))
ts.Close
ReadWMF = HW
End Function

Function ReadBMP(fichero)
Dim fso, ts, s, HW, nbytes
HW = Array("","")
Set fso = CreateObject("Scripting.FileSystemObject")
Set ts = fso.OpenTextFile(Server.MapPath("/" & fichero), 1)
s = Right(ts.Read(24), 8)
HW(0) = HexToDec(HexAt(s,4) & HexAt(s,3))
HW(1) = HexToDec(HexAt(s,8) & HexAt(s,7))
ts.Close
ReadBMP = HW
End Function

Function isDigit(c)
If inStr("0123456789", c) <> 0 Then
isDigit = true
Else
isDigit = false
End If
End Function

Function isHex(c)
If inStr("0123456789ABCDEFabcdef", c) <> 0 Then
isHex = true
Else
ishex = false
End If
End Function

Function HexToDec(cadhex)
Dim n, i, ch, decimal
decimal = 0
n = Len(cadhex)
For i=1 To n
ch = Mid(cadhex, i, 1)
If isHex(ch) Then
decimal = decimal * 16
If isDigit(c) Then
decimal = decimal + ch
Else
decimal = decimal + Asc(uCase(ch)) - Asc("A")
End If
Else
HexToDec = -1
End If
Next
HexToDec = decimal
End Function
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