Class that obtains the image width and height. jpg, GIF, PNG, and BMP are supported.

<%
Class imgwhinfo '': class for retrieving image width and height. jpg, GIF, PNG, and BMP are supported.
Dim Aso
Private sub class_initialize
Set Aso = server. Createobject ("ADODB. Stream ")
Aso. mode = 3
Aso. type = 1
Aso. Open
End sub
Private sub class_terminate
Err. Clear
Set Aso = nothing
End sub

Private function bin2str (BIN)
Dim I, STR
For I = 1 to lenb (BIN)
Clow = midb (bin, I, 1)
If ASCB (Clow) <128 then
STR = STR & CHR (ASCB (Clow ))
Else
I = I + 1
If I <= lenb (BIN) then STR = STR & CHR (ASCW (midb (bin, I, 1) & Clow ))
End if
Next
Bin2str = Str
End Function

Private function num2str (Num, base, lens)
Dim RET
Ret = ""
While (Num> = Base)
Ret = (Num mod base) & RET
Num = (num-num mod base)/base
Wend
Num2str = right (string (lens, "0") & num & ret, lens)
End Function

Private function str2num (STR, Base)
Dim ret, I
Ret = 0
For I = 1 to Len (STR)
Ret = RET * base + CINT (mid (STR, I, 1 ))
Next
Str2num = RET
End Function

Private function binval (BIN)
Dim ret, I
Ret = 0
For I = lenb (BIN) to 1 step-1
Ret = RET * 256 + ASCB (midb (bin, I, 1 ))
Next
Binval = RET
End Function

Private function binval2 (BIN)
Dim ret, I
Ret = 0
For I = 1 to lenb (BIN)
Ret = RET * 256 + ASCB (midb (bin, I, 1 ))
Next
Binval2 = RET
End Function

Private function getimagesize (filespec)
Dim bflag
Dim RET (3)
Aso. loadfromfile (filespec)
Bflag = ASO. Read (3)
Select case hex (binval (bflag ))
Case "4e5089 ":
Aso. Read (15)
RET (0) = "PNG"
RET (1) = binval2 (ASO. Read (2 ))
Aso. Read (2)
RET (2) = binval2 (ASO. Read (2 ))
Case "464947 ":
Aso. Read (3)
RET (0) = "GIF"
RET (1) = binval (ASO. Read (2 ))
RET (2) = binval (ASO. Read (2 ))
Case "535746 ":
Aso. Read (5)
Bindata = ASO. Read (1)
Sconv = num2str (ASCB (bindata), 2, 8)
Nbits = str2num (left (sconv, 5), 2)
Sconv = mid (sconv, 6)
While (LEN (sconv) <nbits * 4)
Bindata = ASO. Read (1)
Sconv = sconv & num2str (ASCB (bindata), 2, 8)
Wend
RET (0) = "SWF"
RET (1) = int (ABS (str2num (mid (sconv, 1 * nbits + 1, nbits), 2)-str2num (mid (sconv, 0 * nbits + 1, nbits), 2)/20)
RET (2) = int (ABS (str2num (mid (sconv, 3 * nbits + 1, nbits), 2)-str2num (mid (sconv, 2 * nbits + 1, nbits), 2)/20)
Case "ffd8ff ":
Do
Do: p1 = binval (ASO. Read (1): loop while p1 = 255 and not ASO. Eos
If P1> 191 and P1 <196 then exit do else ASO. Read (binval2 (ASO. Read (2)-2)
Do: p1 = binval (ASO. Read (1): loop while P1 <255 and not ASO. Eos
Loop while true
Aso. Read (3)
RET (0) = "jpg"
RET (2) = binval2 (ASO. Read (2 ))
RET (1) = binval2 (ASO. Read (2 ))
Case else:
If left (bin2str (bflag), 2) = "BM" then
Aso. Read (15)
RET (0) = "BMP"
RET (1) = binval (ASO. Read (4 ))
RET (2) = binval (ASO. Read (4 ))
Else
RET (0) = ""
End if
End select
RET (3) = "width =" & RET (1) & "" Height = "& RET (2 )&""""
Getimagesize = RET
End Function

Public Function imgw (imgpath)
Dim FSO, imgfile, fileext, arr
Set FSO = server. Createobject ("scripting. FileSystemObject ")
If (FSO. fileexists (imgpath) then
Set imgfile = FSO. GetFile (imgpath)
Fileext = FSO. getextensionname (imgpath)
Select case fileext
Case "GIF", "BMP", "jpg", "PNG ":
Arr = getimagesize (imgfile. Path)
Imgw = Arr (1)
End select
Set imgfile = nothing
Else
Imgw = 0
End if
Set FSO = nothing
End Function

Public Function imgh (imgpath)
dim FSO, imgfile, fileext, arr
set FSO = server. createobject ("scripting. fileSystemObject ")
If (FSO. fileexists (imgpath) Then
set imgfile = FSO. getFile (imgpath)
fileext = FSO. getextensionname (imgpath)
select case fileext
case "GIF", "BMP", "jpg", "PNG":
arr = getimagesize (imgfile. path)
imgh = Arr (2)
end select
set imgfile = nothing
else
imgh = 0
end if
set FSO = nothing
end function
end class
%>
<%
imgpath = "test.jpg"

set pp = new imgwhinfo
W = pp. imgw (server. mappath (imgpath)
H = pp. imgh (server. mappath (imgpath)
set pp = nothing
%>
<%< br> dim W, pxheight
dim PP '// proportion
If W = 0 or W = "" Then
pxwidth = 0
pxheight = 0
else
PP = formatnumber (W/H, 2) '// aspect ratio
end if
If W> = h then
If W> = 300 then
pxwidth = 300
pxheight = formatnumber (300/PP, 0)
else
pxwidth = W
pxheight = H
end if
else
If pheight> = 260 then
pxheight = 260
pxwidth = formatnumber (260 * PP, 0)
else
pxwidth = W
pxheight = H
end if
response. write (pxwidth)
%>

Height = <% = pxheight %>