[Casimiro Notevi]

Y desde tu programa delphi, algo así como esto:

Código Delphi [-]
procedure TForm1.Button1Click(Sender: TObject);
var
  LHTTP: TIdHTTP;
  LIdMultipartFormData: TIdMultipartFormDataStream;
  LResponse: TMemoryStream;
  LEncoding: TEncoding;
begin
  LHTTP := TIdHTTP.Create;
  try
    LIdMultipartFormData := TIdMultipartFormDataStream.Create;
    try
      LIdMultipartFormData.AddFile('file', 'C:\ruta\a\tu\imagen.jpg', 'image/jpeg');
      LResponse := TMemoryStream.Create;
      try
        LHTTP.Post('http://tu-hosting.com/upload.php', LIdMultipartFormData, LResponse, LEncoding);
      finally
        LResponse.Free;
      end;
    finally
      LIdMultipartFormData.Free;
    end;
  finally
    LHTTP.Free;
  end;
end;