User interface for an existing OCR engine

The program should get video images from various sources (file folders and live IP-cameras), submit them to license plate recognition engine and save the results to a database. The programming language should be (in order of preference): VBA for MS Access 2000 Visual Basic Visual C# The program has to work under Windows XP, Vista and 7. The results are saved into MS SQL Server database over ODBC connection. The settings are saved into MS Access database (if developing with VBA) or in a configuration file (if developing with VB or C#). The existing recognition engine (a third party product - a set of .dll libraries) together with working examples in VB and C is being made available to the chosen developer. The code has to be well commented. ## Deliverables If developing in MS Access VBA, the MS Access 2000 file format has to be used. It has to be runnable under MS Access 2000 and 2003. If developing in Visual Basic or Visual C#, the project should be compatible with Visual Studio 2010 Professional. The settings are saved locally. The recognition results are being saved in external database over ODBC (MS SQL Server 2005). The file fetching and recognition have to run in two separate threads. The functionality should be as follows: - when the program is being started (i.e. mdb-file opened by Access, or .exe started), it presents a control form with the following elements: -- button "Start" (starts the recognition cycle; active only when the cycle is stopped) -- button "Stop" (stops the recognition cycle; active only when the cycle is running) -- button "Exit" (exits the program, equivalent to Alt-F4; always active) -- button "Results" (opens another form which shows the results database; always active) -- the small (200x150 pixels) picture window showing the last analyzed picture - if enabled by the "show image" parameter; otherwise blank -- the license plate number returned from that picture -- the name of the source of that picture -- the duration (in milliseconds) of the last cycle -- the current length of the VPAR queue (i.e. the count of unprocessed images) -- status window (shows the log of the last activities: error messages and recognition results) which resizes together with the form and auto-scrolls when full; a click on the status window will pause the refreshing of the window; another click resumes; the log lines inserted during the paused state should not be lost, but displayed after resuming -- list of data sources; the count of data sources should be unlimited; for each datasource there are the following parameters: --- datasource name (max 30 characters, can contain blanks and special characters) --- enabled (yes/no) --- data source type (4 variants): ---- UNC to file folder with JPG images (e.g. "\\server\folder\subfolder") ---- URL to file folder with JPG images (e.g. "ftp://server/folder/subfolder" or "http://server/folder/subfolder") ---- URL to live MJPEG feeds from video cameras (e.g. "http://server:80/axis-cgi/mjpg/[login to view URL]") ---- URL to jpg-image from video cameras (e.g. <http://server:80/[login to view URL]>) --- data source location (examples given by the data source type) --- skip (integer) - how many cycles should be skipped between each polling of this source ("0" means - will be polled on every cycle; this is default) --- parameters for the quadrilateral transformation (coordinates of 4 corners of the original image and dimensions of the resulting image) -- list of configurable parameters: --- ODBC DSN and table name for storing the result --- minimal duration of each cycle (in milliseconds) --- startup delay - wait time before auto-startup (in seconds) --- image folder - the folder name for saving the processed images --- save fails (yes/no) - whether to save the data about failed recognitions to the database --- show image (yes/no) - whether to show the image of the last processed picture on the control form --- VPAR queue limit - how many images can be in the VAPR queue to start the new cycle - next it loads the last set of parameters and waits for "startup delay" (parameter) seconds for user input - if no button has been clicked or data entered during this time, automatically starts the endless recognition cycle (as of the "Start" button had been clicked) - if there was some user activity during the startup delay time, the auto-startup is canceled and the cycle is started only after user clicks the "Start" button - during the recognition cycle the program: -- checks (considering the "skip" parameter) first enabled data source if at least one jpg-file exists in the folder (for camera - if the image is being returned from the query); if yes, the oldest file is being fetched and deleted; if nothing found, the next enabled data source is checked until an image has been found -- if corresponding parameters are set, image is processed by quadrilateral transformation (QLT) routine -- the resulting image is queued for asynchronous VPAR processing -- the next enabled data sources from the list are being checked and images processed in the same manner -- after all the enabled data sources have been checked, the program shows the duration of the cycle on the corresponding field of the status window -- waits until the minimal duration of the cycle has passed and VPAR queue length is below the limit -- starts over with the first enabled data source - the VPAR queue is being handled asynchronously of image fetching: -- the image is taken from the queue and processed by VPAR module -- the image is saved (considering the "save fails" setting) to the file folder shown in the corresponding parameter (each day has its own subfolder, named as "yyyy mm dd"; the filename consists of the data source name, blank and time in format "[login to view URL]" - e.g. "Camera One [login to view URL]") -- the following data about recognition is saved (considering the "save fails" setting) to the external database: --- date --- time --- data source name --- original filename (without URL/UNC) --- license plate number (the recognition result) --- confidence % -- the corresponding fields of the control form are polulated with result data -- a line is being written to the status window, containing: time, data source, recognised number and confidence % (or error message if there was a processing error) - the data source and parameter lists are editable when the cycle is stopped, after starting the cycle they become non-editable until the cycle is stopped again - every change in data sources and parameters is being immediately saved to the database (to guarantee that a subsequent start of the program always uses the last settings) - the "Results" form: -- shows a read-only grid with data from the result database (sorted by date and time in descending order) -- in the header of it should be a tickmark "show image" - when enabled, an image corresponding to the active row is being automatically shown in a corresponding window -- the filename for the image is not in the database, it has to be generated on the basis of the data in the database Remarks: The MJPEG handling and QLT can be handled by AForge .NET framework libraries. The VPAR processing has to run in a separate, asynchronous thread because it consumes the most of the CPU power. The main thread does the image fetching (which involves much waiting for external devices) and feeding the VPAR thread with images. The application should be usable in the 800x600 window. If the main form becomes too crowded, some or all the configuration data can be moved to a separate form - this is up to the programmer.