There are two different approaches that can be taken to reducing file size.
Both of these use the VB function LenB() in conjunction with the .Binary property of AspJpeg to determine the current file size.
This requires AspJpeg version 1.3 or higher.
Method 1: Progressively reduce image quality
<%
Set Jpeg = Server.CreateObject("Persits.Jpeg")
'change as needed
Jpeg.Open "c:\path\file.jpg"
iQuality = 80
While LenB(Jpeg.Binary) > 150000 '150 kilobytes
'a lower number will mean more iterations
iQuality = iQuality - 5
Jpeg.Quality = iQuality
Wend
Jpeg.Save ...
%>
Method 2: Progressively reduce image size
<%
Set Jpeg = Server.CreateObject("Persits.Jpeg")
iScale = 100
Do
' It is recommended to have the Jpeg.Open statement
' within this loop to avoid quality loss due to
' multiple resizes of the original image.
Jpeg.Open "c:\path\file.jpg"
Jpeg.Height = Jpeg.OriginalHeight * iScale / 100
Jpeg.Width = Jpeg.OriginalWidth * iScale / 100
'a lower number will mean more iterations
iScale = iScale - 5
Loop While LenB(Jpeg.Binary) > 150000 '150 kilobytes
Jpeg.Save ...
%>
You can also write code to do both size and quality reductions in the same script.
Note that these operations are CPU-intensive. It is recommended that these methods be used
when accepting uploaded images or saving images to a database, not for displaying thumbnails.
