JPEG dimensions 1

[Rydel]

How can I determine the dimensions of a JPEG file using VBScript (either under ASP or as WSH)?

Big thanks in advance.

regards,
rydel n23

http://pravapis.org/

http://rydel.net/

 

[Rydel]

I have found this piece of code, but it doesn't work. It does get the name correctly, it does open the file, it does read the bytes, but it does NOT return the values for height and width, with several JPEGs that I've tried.

Sub GetJpegDims(ByVal strFileName, ByRef lngHeight, ByRef lngWidth)
'on error resume next
Dim stmFile
set stmFile = server.createobject("ADODB.Stream")
Dim bytArr(256)
dim byt
Dim intPos
With stmFile
.Type = 1 'adTypeBinary
.Open
.LoadFromFile strFileName
.Position = 0

for intPos = 0 to 255
.position = intpos
bytArr(intPos) = ascb(.Read(1))
response.write(ascb(.Read(1)))
response.write(" ")
next
.Close
End With
Set stmFile = Nothing

For intPos = 0 To 255
If bytArr(intPos) = &HFF And bytArr(intPos + 1) >= &HC0 _
And bytArr(intPos + 1) <= &HCF Then
lngHeight = bytArr(intPos + 5) * 256 + bytArr(intPos + 6)
lngWidth = bytArr(intPos + 7) * 256 + bytArr(intPos + 8)
Exit For
End If
Next
End Sub

Dim h2, w2, fname

fname = Server.MapPath("img1.jpg")

Response.Write(fname)

Call GetJpegDims(fname,h2,w2)

Response.Write(h2+"<br>")
Response.Write(w2)


regards,
rydel n23

http://pravapis.org/

http://rydel.net/

 

[tsuji]

I don't know why you say it does not work. It should and it does.

The simplest way to get the dimension in pixel, though, is to use native loadpicture function. It has limitation on the pic formats and some other aspects. But common formats bmp, ico, jpg and gif are supported.
[tt]
set opic=loadpicture(server.mappath("img1.jpg"))
'height and width properties return in himetric (0.01mm)
'numeric factors are just to convert them to pixel
h2=round(opic.height/2540*96)
w2=round(opic.width/2540*96)
set opic=nothing
response.write h2 & " x " & w2 & " (HxW in unit pixel)<br />"
[/tt]

 

[Rydel]

Thank you. A star for you. Stupid me, I didn't realize there's an internal VBScript function since Ver.2.0... That's a real "RTFM".

regards,
rydel n23

http://pravapis.org/

http://rydel.net/

 

[markdmac]

I'll give a star for that since Rydel didn't. Very nice tip tsuji.

I hope you find this post helpful.

Regards,

Mark

Check out my scripting solutions at

http://www.thespidersparlor.com/vbscript