Image Processing

[dvst8]

I need to do some dynamic thumbnailing from ASP, and I've decided to write a VB Component to do this.

This is what I know:
I'll write an ActiveX dll, which will contain a function. From asp I will call this function with one argument, namely the path to the image I want to thumbnail. In VB this function will accept this string as a Variant. Once I associate this String to an image object, then I can do what I need to do (i.e calculate aspect ratio, set stretch to true, resize it and save it). I'll return a boolean representing success/fail.

What I don't know:
1)I don't know how to go from the step of having the filename as a String and actually getting an Image to work with.


Thanks!
dvst8

[delker]

Look up the LoadPicture function. You can use it something like this:

Picture1.picture = LoadPicture(filenamestring)

There are some other args you can pass it, such as colordepth, height and width.

[dvst8]

thanks!
jsut what i needed. will look that up.

/d8

[dvst8]

Here is the code I have;

Option Explicit

Public Function goImage(myFileName As Variant) As Boolean
    On Error Resume Next
    Dim Picture1 As Object

    myFileName = CStr(myFileName)
    Picture1.Picture = LoadPicture(myFileName)

    If Err.Number <> 0 Then
        goImage = False
    Else
        goImage = True
    End If

End Function

I've put this in a class called ImageFun, in a project named Fun.dll. After compiling this .dll and registering it on the server, I tried calling it from ASP with the following:

set foo=Server.CreateObject("Fun.ImageFun")

Which gives me the error: "Invalid class string"

Does that make sense?

Another question: Since it's an activeX dll, there is no form. I'm assuming that normally Picture1 would be the name of a Picture control that you would embed on a form. In my code I simply declare Picture1 as an object. Is this sufficient? Or do I have to declare it as something else?

Thanks
dvst8

[Edited by dvst8 on 06-26-2000 at 08:56 PM]