LPR SETUP AND FIELD INSTALLATION GUIDE

Transcription

1 LPR SETUP AND FIELD INSTALLATION GUIDE Updated: May 1, 2010 This document was created to benchmark the settings and tools needed to successfully deploy LPR with the ipconfigure s ESM 5.1 (and subsequent versions). Specific hardware and software was used to obtain optimal settings, namely: Axis P1346 IP Camera, Fujinon 3MP 8/80mm lens (Part # DV10X8SA-1) and ipconfigure s standalone LPR Console utility program. Testing was conducted with the following environmental conditions: daylight hours, no extra light included (white or infrared), and dawn to dusk timeframe for normal operations. 1

2 TABLE OF CONTENTS Testing Scenarios 3 Axis Recommended Settings for P1346 Camera 4 10 Adjusting Camera LPR FOV 8 10 Explanation of Camera Settings Sharpness Setting on P Brightness Setting on P Exposure Setting on P Ideal Settings on P LPR Console ipconfigure s LPR configuration utility ipconfigure ESM ADMIN UI LPR Setup Tab 18 Server Updates 19 Lens Data 19 Environmental Considerations 20 2

3 TESTING SCENARIOS This describes the various speeds at which the vehicles were traveling and the angle of the read relative to the camera field of view (FOV) from center as the vehicle passes through the image. Distance testing was done from 50 feet to 150 feet. The ideal FOV width, based on distance out from the camera, is 1 to 1.5 cars wide. This will give you the required pixel count (at a minimum of 200 pixels wide and 125 pixels high) of the plate data to run the application correctly. The camera was mounted at a maximum of 10 feet above ground. IDEAL FRAME RATE FOR TRAFFIC SCENARIOS Based on the different scenarios relative to the FOV and the motion through that FOV, this part defines the best frames per second setting to use. STOP SIGN completely stopped Straight shot (no + or - from center of the camera s FOV): 5 frames per second, setup in LPR Console utility or ESM Admin UI Angle of read (+ or - 5 to 20 from the center of the camera s FOV): 5 frames per second, setup in LPR Console utility or ESM Admin UI NOT COMING TO STOP but motion through the frame Straight Shot 5-15 mph 5 frames per second, setup in LPR Console utility or ESM Admin UI Straight Shot mph 5 frames per second, setup in LPR Console utility or ESM Admin UI Angle of read & 5 15 mph + or - 5 to 20 from the camera s center FOV: 5 frames per second, setup in LPR Console utility or ESM Admin UI Angle of read & mph + or - 5 to 20 of camera FOV center: 5 frames per second, setup in LPR Console utility or ESM Admin UI Angle of read & 5 15 mph + or - 21 to 30 of camera FOV center: 5 frames per second, setup in LPR Console utility or ESM Admin UI 3

4 AXIS RECOMMENDED SETTINGS FOR P1346 CAMERA INITIAL CAMERA SETUP 1. Log onto the camera directly. Axis cameras default IP Address is: Check that the camera is running LPR firmware version P1346_5_05_beta39_lpr2.bin (contact ipconfigure for a copy of this firmware). and the Fujinon 8/80mm lens is attached. After firmware version has been verified or has been successfully uploaded perform the following setup steps 3. Select Setup Basic Setup Video Stream Image. The first time you login to the camera you will be asked to apply a CAPTURE MODE - we require this to be set to 2 MP 1600x1200 (4:3). (Note: If you have to factory default the camera at some point in the future you will need to re-apply this setting). At initial login to camera or under Basic Setup 4. Video Stream set to the following: 1 Under Image Appearance Capture mode set Resolution to: 1600x1200 (4:3) 2 Set Compression level to 1 4

5 3 Save these settings Under System Options Advanced Plain Config Select a group pf parameters to modify: 1. Select ImageSource from the list 2. Click on Select group ImageSource I0 3. Select Imaging mode: Mode1. (if no option is available you are not using the appropriate firmware) 4. At the bottom of the page click on Save and scroll back up to the top of the page and click on Setup.) 5

6 Under Video & Audio Camera Settings set the following: Image Appearance: 1. Set Color level to Set Brightness to Set Sharpness to Set Contrast to 65 (The above settings should be used as a starting point for operation on a sunny day.) Exposure Settings: 5. Set Exposure priority to: Low noise 6. Set the Exposure value to: 70 (ideal range is 60-70) 7. Set Shutter Min: 1/17000 (or 1/35000) 6

7 8. Set Shutter Max: 1/ Set Gain Min: Set Gain Max: 9 Exposure Settings: 11. Ensure that Enable Backlight compensation is not checked Wide Dynamic Range: 12. Ensure that Enable Dynamic Contrast is not checked Exposure Settings: 13. Set IR cut filter to: On 14. Ensure that Automatic iris adjustment is checked View Image Settings: 15. Click on Save to save these settings. 7

8 ADJUSTING CAMERA LPR FOV Before continuing, it is important to understand FOV and how this relates to the camera and the optimal settings related to distance, height, FOV, depth of field, and width of view. The following diagram will help understand Camera Placement, width and height of FOV and the LPR capture range. 8

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10 Under Setup Video & Audio Focus, we set the focus on the camera: 1 Draw a focus window around the area of interest, which will produce the best depth of field and coverage for plate detection zones. 2 Put a check in the Show pixel counter box on the above and drag and it across the FOV that you want to act as the focus area for plate detection within the window. 3 Proceed through the auto focus adjustment steps. (This should be done with as little motion in the scene as possible). You may need to focus this a few times if the scene changes (experiences motion) throughout this process. You need to focus at the point where the ideal plate size of at least 200 pixels exists on the counter. After determining where the optimal FOV is you will need to stop a vehicle in the image and perform this focus process. a. Click on the button. b. Click on the button. c. Click on the button. 10

11 d. NOTE: You can click on the tab at this point to fine tune the auto focus manually after it resets. This should be done if the image does not automatically refocus to an ideal picture. e. Click on the button to close this session of Focusing the FOV on the camera. EXPLANATION OF CAMERA SETTINGS SHARPNESS Adjust the sharpness value as necessary to produce images that are acceptable to the eye and software. Lower sharpness values are typically better for LPR. Values ranges should be

12 BRIGHTNESS Adjust the brightness value. Values ranges should be Mid to higher values are typically better for LPR. EXPOSURE Adjust the exposure values. Values ranges should be Mid to higher values are typically better for LPR. The exposure values are only going to work in accordance with the Max Shutter speed and the available light in the FOV during the time of day. If the camera is running at dusk hours, over exposing (or increasing exposure value) of the image will show no noticeable gain due to the camera running at the Max Shutter speed already. IDEAL SETTINGS ACROSS THE BOARD Example of Optimal Configuration for this particular scene Brightness= 65, Sharpness=15, Contrast=65, Exposure=55 Example of OCR with optimal Configuration for this particular scene: Brightness= 65, Sharpness=15, Contrast=65, Exposure=55 12

13 NOTE: Refer to the above image, note the distinct tone of the blue. Also the crisp edges of the character sets, you can clearly see the blue on the white. It is a bright white and deeper blue, not speckled or grainy or run together. That is the sort of the image that the LPR engine processes with much greater accuracy. LPRCONSOLE- IPCONFIGURE S LPR CONFIGURATION UTILITY PRGRAM LPRCalibrate.exe is a file that you need to run on the Windows Server where the ESM/LPR application is installed. Extract files into C:\Program Files\ipConfigure\LPRCalibrate and double click on LPRCalibarate.exe to launch the LPR Console utility. The goal of using the LPR Console utility is to properly tweak the camera settings after the FOV and initial setup has been completed above and use the information gathered to go back and tweak the camera settings if needed. As you click on the Start LPR button and start to see what is being passed to the LPR engine and the database tables. It will become clear if you have a good image or bad image based on current camera settings, FOV, area of Focus, etc. QUICK TIP: More than likely the cameras will already be setup on the Windows Server when ESM 5.1 was installed. From LPR Console utility click on the button and choose the camera you want to work with. You will need to click on the button to start working within the FOV of the camera you selected. When your work is completed, click on the and then restart all ipconfigure services on the Windows Server (Start Administrative Tools Component Services Services). 13

14 DETAILS OF THE ITEMS ABOVE: 1. Configuration Area of Live View: This is an active live view window of the camera you connect to. The red box designates where on the screen you want the plate to be detected. It should be at a minimum of 200 pixels across within the image. This setting has a threshold of 10% either way for optimal reads. 2. LPR Results: This contains two pieces of information. The Larger Font character set is the image that the segmentation engine in LPR has identified as a possible plate. The Small Font Character set is the LPR result output after the engine has examined the possible plate and is the text that will be stored. 3. Reference Plate Zoom: This window allows the user to see more closely what the LPR engine sees and fine tune the camera settings to maximize the read rate of the system. 4. IP Address: This would be the IP address of the LPR designated camera you want to connect to 5. User: User for the camera most will be root. 6. Password: Password for camera user login. 7. FPS: Frames per second 5FPS is ideal. It may be greater with higher traffic areas or be less at cameras viewing stop signs on busy roads. 8. Compression: set this to 1. 14

15 9. or : This will allow you Connect to above camera or disconnect. Note that you must do this if making changes to the FOV settings in order for it to be pushed to the camera for detection. 10. or : This will start or stop the LPR engine from running on the detected image and plate parameters configured in the Configuration Area of Live View. 11. : This allows you to connect to LPR designated cameras on Server that will be hosting the LPR application. Due to the nature of the security involved, you must do this from the Server itself, do not run this on a laptop/workstation. 12. : This will allow you save all settings in a SQL Table on the Server to the designated LPR camera. Due to the nature of the security involved, you must do this from the Server itself. 13. : Click on this box to start to draw your LPR reference window, this is the larger red rectangle you see in the Configuration Area of Live View section. Remember this must be at least 200 pixels wide for best results. If it is not 200 pixels on the native image then zoom in more on the FOV and refocus the camera. 14. UL: Upper Left coordinates of plate detection window. The detection window is reference only for the system and it is not necessary to be in the exact location that a plate will be found. 15. UR: Upper Right coordinates of plate detection window. The detection window is reference only for the system and it is not necessary to be in the exact location that a plate will be found. 16. LL: Lower Left coordinates of plate detection window. The detection window is reference only for the system and it is not necessary to be in the exact location that a plate will be found. 17. LR: Lower Right coordinates of plate detection window. The detection window is reference only for the system and it is not necessary to be in the exact location that a plate will be found. 18. Motion Skew: optimal setting is 0. The LPR engine contains automatic motion skew correction and this value can be used to override this but is rarely necessary. 15

16 19. Kernel Size: optimal setting is 31. This is the size of the convolution kernel used to enhance the plate image. The default of 31 is optimal for most conditions and should not be changed. 20. Threshold: optimal setting is 125. This is the pixel color level threshold used to increase contrast between dark and light colors. The default of 125 is optimal and the LPR engine will automatically adjust this value internally pursuant to ambient light conditions. 21. Reference Plate: This is the width and height of the plate detection window respectively. 22. OCR: This is the training file set that the LPR engine should use to recognize the plate numbers and letters. These files exist in the LPRConfig subdirectory and are typically named plate.*, texas.*, etc. 23. High Conf Min: This determines the minimum number of characters that must be found for the LPR Engine to return as a possible plate. This includes the space in the middle of the character set. If there is a plate read under this value, it will not be recorded. Ideal setting is High Conf Max: This determines the maximum number of characters that must be found for the LPR Engine to return as a possible plate. If the LPR Engine finds a character string longer than this value, it assumes it has a misread. This includes the space in the middle of the character set. This includes the space in the middle of the character set. If there is a plate read over this value, it will not be recorded. Ideal Setting is Use Background Segmentation: This determines whether or not the system use motion detection to trigger plate reads. If background segmentation is on, motion is required to wake up the system. This should normally be on unless tuning is being done with a reference object that is stationary in the camera field of view. If background segmentation is off, the LPR engine evaluates every image whether it has motion or not. 26. Scale: For background segmentation, the image can be scaled before it is processed for motion. Scale of 1 means no scaling. Sometimes for large, high resolution images, it is necessary to scale the image down to improve performance. Scale of 0.4 means scale the image to 40% of its original size before analysis. 27. Box Size: The minimum size of a rectangle in the image which will be returned as motion. For instance, if motion is detected in a rectangle that is 100 pixels wide and 50 pixels high, Box Size must be at least 5000 (1000x50) or this area won t be returned as motion. Larger box sizes increase performance but don t see objects at a great distance. Ideal setting is

17 28. Burn Rate: Determines how quickly an object that comes into the foreground becomes part of the background and is no longer seen as a foreground object with motion. Slow burn rates generate lots of motion and analyze the image more times. High burn rate lets a car come into the field of view and if at a stop sign, ceases analyzing the vehicle after a short period of time as the car becomes part of the background (no motion). Ideal setting is Threshold: Tuning parameter for increasing contrast between light and dark pixels. Any pixels with a color value below this are dropped to zero. Ideal setting is Pre-Erode: Number of iterations to erode the image before dialation. Rarely should this be changed. 31. Dialate: Number of iterations to dialate the image. Rarely should this be changed. 32. Post-Erode: Number of iterations to erode the image after dialation. Rarely should this be changed. 33. Sleep: Number of milliseconds that the LPR engine should sleep if no motion is found in a frame. This should never be set to a value more than 1000 but can greatly decrease CPU usage with a value in the 200 millisecond range. If background segmentation is off, the engine never sleeps. Ideal setting is Draw Motion Rectangles: Checking this instructs the LPR console to draw (in yellow rectangles) the motion that it sees during background segmentation. If background segmentation is disabled, you are responsible for drawing up to 5 hot boxes in which the LPR Engine looks for valid plate images. In other words, if background segmentation is enabled, the system finds it s own hot boxes by looking for motion in the images. If Draw Motion Rectangles is checked, the screen will show the motion that is found. This setting has no impact on what is stored in the database as is intended to be a diagnostic tool. 35. : This is used to load a static image to process in the engine and examine results. 36. : Point this to a folder of JPEG images and it will allow you to step through them and test the readability of the images that have been recorded. 37. : After an image is loaded with Load Image, this processes it once. 38. JPEG Quality: Determines the quality of the JPEG images stored in the ESM database. This value ranges from 1 (lowest quality) 100 (highest quality). Start at 30 and see if the recorded data is visible by the human in the User GUI, the 17

18 goal here is to put a smaller file size in the User GUI for WAN optimization. Typical values range from IPCONFIGURE LPR SETUP TAB The settings you see below are the defaults for all cameras and should rarely be changed. These settings are pushed to the camera from the LPR Console configuration utility and populate the local database table on the Server. Changing them in the below will result in a database table change. CAMERA SETTINGS IN ESM ADMIN UI: - With only the LPR Dedicated cameras, this setting is really not in use. When the camera is discovered in ESM, it will populate with some default settings. You can use these settings going forward and there is no need to change them. The settings in the LPR Console utility will override any settings made here. 18

19 LPR SETUP IN ESM ADMIN UI: The Typical coordinates of Plate in Image: These settings will mirror the settings you end up with after using the LPR Console utility to find the ideal settings based on the environment. This will be the coordinates displayed within the application mentioned in the above section. The License Plate Recognition Settings: Motion Skew = 0 is the only setting it should be set at. Image Enhancement = 31 is the only setting it should be at. Sensitivity = 125 is the only setting it should be set at. Overview Camera = This should be an exterior camera at the facility, that is not an LPR dedicated camera. Currently all Optional Overview Cameras are Axis 211M models. These secondary cameras do the video recording on a wider view. This will need to be set manually on this page. All other settings can hardcoded from the camera with the LPR Console utility. SERVER UPDATES The following files are required to be updated on the Server: LPRGateway.dll SQL Table Row Add and Schema Change. Plate templates for font sets of States that you are processing act as the determining factor in the success of the LPR Engine. These templates reside in C:\Program Files\ipConfigure\LPRConfig\*.* If we were configuring for Texas, we would see 10 or so files with texas.* in the folder. LENS DATA Test conducted used a Fujinon F1.4 8/80mm lens (Manufacturer s Part # DV10- x8sa-1). From our testing this lens will create good pixel counts when properly adjusted for FOV from ranges 50 to 150 feet. 19

20 ENVIRONMENTAL CONSIDERATIONS Dusk certainly presents issues and it seems to come in about 5 minute clips. Once you get the settings working with the current available light and the LPR engine is reading good data, wait 5 minutes, the accuracy will go down. This sort of manual tweaking is not really worth the 5 extra minutes per day of valid plate data that would be obtained. Not to mention you can interrupt normal daytime operations if you start to mess with Max Shutter Speeds and Exposure values to increase the light of the image. What sort of lighting is notice for the environment? There may be some image quality issues around the thermal off the ground, especially in Texas on hot days where blacktop is present. This can be noticed in the images if they seem wavy and rigid when zoomed in on them. Due to the height at which we hang the cameras off the side of the building, this should dissipate from our view. We saw it when the camera was about 3 feet off the ground, it disappeared when moving the camera to 10 feet and higher. 20