WIA 2 on Windows 7 -- Delphi

Question

WIA 2 on Windows 7 doesn't detect my camera while WIA 1 on Windows XP detects it.

I try to run my program as admin.

My camera is :

Asus usb2 webcam.

Delphi return the message:

(like this) not available any wia devices from specified type

or

Access Violation at address ...... in module ......

I use this code:

procedure TForm1.Button9Click(Sender: TObject);
Const
   wiaFormatBMP ='{B96B3CAB-0728-11D3-9D7B-0000F81EF32E}';
var
   CommonDlg: ICommonDialog;
   AImage: IImageFile;
   ImagePath: String;
   DeviceManager1 :iDeviceManager;
begin
   CommonDlg := createOleObject('WIA.CommonDialog') as ICommonDialog;
   DeviceManager1 := createOleObject('WIA.DeviceManager') as  iDeviceManager;
   edit1.Text:=  inttostr( DeviceManager1.DeviceInfos.Count);
   AImage := CommonDlg.ShowAcquireImage(UnspecifiedDeviceType,UnspecifiedIntent,
                                        MaximizeQuality,wiaFormatBMP,true,False,True);
   ImagePath := 'C:\temp\test.bmp';
   AImage.SaveFile(ImagePath);
end;

Answer 1

I recently had a similar experience with WIA and Win7.

What I eventually ended up using was a DirectX solution.

Delphi Basics - DirectX webcam capture

I don't remember how I originally found this project, but under Win7 it just works even with older webcams that I found lying around the office.

I recommend you look at Demo3 in the download file as that had the best, simple, example of what I needed. YMMV.

(Edit) My WIA problem extended from the fact that the webcam maker did not support WIA or Twain under Win7.