Table Of Contents

Author

1. General Specifications

1.1 Requirements

1.2 Software:

1.3 Hardware:

2. Usage

2.1 Run the System

python pi_tensorflow_lite_object_detection.py --folder-name"events" --log-file"logfile.log"

2.2 Access the Web Interface

3. Demo

3.1 Human detector

3.2 Banana detector

3.3 Cat detector

4. Code

4.1 class LEDRGB and class LEDSRGB

classLEDRGB:colors= {"red": (1,0,0),"green": (0,1,0),"blue": (0,0,1),"yellow": (1,1,0),"magenta": (1,0,1),"cyan": (0,1,1),"white": (1,1,1),"off": (0,0,0)    }def__init__(self,red_led,green_led,blue_led):GPIO.setmode(GPIO.BCM)self.red_led=red_ledself.green_led=green_ledself.blue_led=blue_ledGPIO.setup(self.red_led,GPIO.OUT)GPIO.setup(self.green_led,GPIO.OUT)GPIO.setup(self.blue_led,GPIO.OUT)def_set_color(self,color_name):color=self.colors.get(color_name.lower(),self.colors["off"])GPIO.output(self.red_led,color[0])GPIO.output(self.green_led,color[1])GPIO.output(self.blue_led,color[2])def__getattr__(self,color_name):returnlambda:self._set_color(color_name)classLEDSRGB:def__init__(self,leds):self.leds= [LEDRGB(*led)forledinleds]defset_color(self,color_names):ifisinstance(color_names,str):fori,ledinenumerate(self.leds):getattr(led,color_names)()elifisinstance(color_names,list)andlen(color_names)==len(self.leds):for (led,color)inzip(self.leds,color_names):getattr(led,color)()def__getattr__(self,color_name):returnlambda:self.set_color(color_name)

4.2 class Buzzer

classBuzzer:def__init__(self,pin=12,frequency=5000,duty_cycle=50):self.pin=pinGPIO.setmode(GPIO.BCM)GPIO.setup(self.pin,GPIO.OUT)self.frequency=frequencyself.pwm=GPIO.PWM(self.pin,self.frequency)self.duty_cycle=duty_cycleself.active=Falsedefauto_stop(self,cycles=3,duration=0.1):ifnotself.active:self.active=Truefor_inrange(cycles):self.start()time.sleep(duration)self.stop()time.sleep(duration)self.active=Falsedefstart(self):self.pwm.start(self.duty_cycle)defstop(self):self.pwm.stop()

4.3 class ObjectDetector and class Camera

classObjectDetector:def__init__(self,model_name="efficientdet_lite0.tflite",num_threads=4,score_threshold=0.3,max_results=1,category_name_allowlist=["person"]):base_options=core.BaseOptions(file_name=model_name,use_coral=False,num_threads=num_threads)detection_options=processor.DetectionOptions(max_results=max_results,score_threshold=score_threshold,category_name_allowlist=category_name_allowlist)options=vision.ObjectDetectorOptions(base_options=base_options,detection_options=detection_options)self.detector=vision.ObjectDetector.create_from_options(options)defdetections(self,image):rgb_image=cv2.cvtColor(image,cv2.COLOR_BGR2RGB)returnself.detector.detect(vision.TensorImage.create_from_array(rgb_image)).detectionsclassCamera:def__init__(self,frame_width=1280,frame_height=720,camera_number=0):self.video_capture=cv2.VideoCapture(camera_number)self.video_capture.set(cv2.CAP_PROP_FRAME_WIDTH,frame_width)self.video_capture.set(cv2.CAP_PROP_FRAME_HEIGHT,frame_height)defframe(self):_,frame=self.video_capture.read()returnframe

4.4 class RealTimeObjectDetection

classRealTimeObjectDetection:def__init__(self,frame_width=1280,frame_height=720,camera_number=0,model_name="efficientdet_lite0.tflite",num_threads=4,score_threshold=0.3,max_results=1,category_name_allowlist=["person"],folder_name="events",storage_capacity=32,led_pines=[(13,19,26), (21,20,16)],pin_buzzer=12,frequency=5000,duty_cycle=50,fps_frame_count=30,safe_zone=((0,0), (1280,720))):self.frame_width=frame_widthself.frame_height=frame_heightself.camera=Camera(frame_width,frame_height,camera_number)self.frame=self.camera.frame()self.object_detector=ObjectDetector(model_name,num_threads,score_threshold,max_results,category_name_allowlist)self.folder_name=folder_nameself.storage_manager=StorageManager(folder_name,storage_capacity)self.storage_manager.supervise_folder_capacity()self.leds_rgb=LEDSRGB(led_pines)self.buzzer=Buzzer(pin_buzzer,frequency,duty_cycle)self.safe_zone_start,self.safe_zone_end=safe_zoneself.fps_frame_count=fps_frame_countself.last_detection_timestamp=Noneself.frame_buffer= []self.frame_times= []self.output= {}self.events=0self.fps=24defguard(self,min_video_duration=1,max_video_duration=60,max_detection_delay=10,event_check_interval=10,safe_zone=False):try:self.buzzer.auto_stop()self.leds_rgb.set_color(["off","green"])whileself.isOpened():security_breach,time_localtime=self.process_frame((0,0,255),1,2,cv2.FONT_HERSHEY_SIMPLEX,safe_zone)ifsecurity_breach:ifnotself.frame_buffer:self.output["file_name"]=time.strftime("%B%d_%Hhr_%Mmin%Ssec",time_localtime)self.output["day"],self.output["hours"],self.output["mins"]=self.output["file_name"].split("_")self.output["path"]=os.path.join(self.folder_name,self.output["day"],self.output["hours"],f"{self.output['file_name']}.mp4")eliflen(self.frame_buffer)==int(self.fps):buzzer_thread=threading.Thread(target=self.buzzer.auto_stop)buzzer_thread.start()self.leds_rgb.red()self.last_detection_timestamp=time.time()self.frame_buffer.append(self.frame)else:ifself.last_detection_timestampand ((time.time()-self.last_detection_timestamp)>=max_detection_delay):iflen(self.frame_buffer)>=self.fps*min_video_duration:self.save_frame_buffer(self.output["path"],event_check_interval)self.leds_rgb.set_color(["off","green"])self.last_detection_timestamp=Noneself.frame_buffer= []self.output= {}eliflen(self.frame_buffer)>=self.fps*max_video_duration:self.save_frame_buffer(self.output["path"],event_check_interval)exceptExceptionase:logging.error(e,exc_info=True)GPIO.cleanup()self.close()os._exit(0)defsave_frame_buffer(self,path,event_check_interval=10):output_seconds=int(len(self.frame_buffer)/self.fps)os.makedirs(os.path.dirname(path),exist_ok=True)out=cv2.VideoWriter(path,cv2.VideoWriter_fourcc(*"avc1"),self.fps, (self.frame_width,self.frame_height))logging.warning(f"EVENT:{output_seconds} seconds{path}")forframeinself.frame_buffer:out.write(frame)out.release()self.events+=1ifself.events%event_check_interval==0:storage_thread=threading.Thread(target=self.storage_manager.supervise_folder_capacity)storage_thread.start()def_safe_zone_invasion(self,rect_start,rect_end):ifself.safe_zone_start[0]>rect_end[0]orself.safe_zone_end[0]<rect_start[0]:returnFalseifself.safe_zone_start[1]>rect_end[1]orself.safe_zone_end[1]<rect_start[1]:returnFalsereturnTruedefprocess_frame(self,color=(0,0,255),font_size=1,font_thickness=2,font=cv2.FONT_HERSHEY_SIMPLEX,safe_zone=False):security_breach=Falsestart_time=time.time()frame=self.camera.frame()time_localtime=time.localtime()detections=self.object_detector.detections(frame)fordetectionindetections:box=detection.bounding_boxrect_start= (box.origin_x,box.origin_y)rect_end= (box.origin_x+box.width,box.origin_y+box.height)category_name=detection.categories[0].category_nametext_position= (7+box.origin_x,21+box.origin_y)cv2.putText(frame,category_name,text_position,font,font_size,color,font_thickness)cv2.rectangle(frame,rect_start,rect_end,color,font_thickness)security_breach=self._safe_zone_invasion(rect_start,rect_end)cv2.putText(frame,time.strftime("%B%d/%Y %H:%M:%S",time_localtime), (21,42),cv2.FONT_HERSHEY_SIMPLEX,font_size,color,font_thickness)ifsafe_zone:cv2.rectangle(frame,self.safe_zone_start,self.safe_zone_end, (0,255,255),font_thickness)self.frame=frameself.frame_times.append(time.time()-start_time)ifself.fps_frame_count==len(self.frame_times):average_frame_time=sum(self.frame_times)/len(self.frame_times)self.fps=round(1/average_frame_time,2)self.frame_times= []returnsecurity_breach,time_localtimedefisOpened(self):returnself.camera.video_capture.isOpened()defclose(self):self.camera.video_capture.release()

4.5 class StorageManager

classStorageManager:def__init__(self,events_folder="events",storage_capacity=32):self.events_folder=events_folderself.storage_capacity=storage_capacity@staticmethoddeffolder_size_gb(folder_path):total_size_bytes=0fordirpath,_,filenamesinos.walk(folder_path):forfilenameinfilenames:file_path=os.path.join(dirpath,filename)total_size_bytes+=os.path.getsize(file_path)returntotal_size_bytes/ (1024**3)@staticmethoddefdelete_folder(folder_path):folder_size=StorageManager.folder_size_gb(folder_path)shutil.rmtree(folder_path)logging.warning(f"STORAGE: '{folder_path}' was deleted (-{folder_size:.4f} GB)")returnfolder_sizedefsupervise_folder_capacity(self):events_folder_size=StorageManager.folder_size_gb(self.events_folder)logging.info(f"STORAGE: '{self.events_folder}' is ({events_folder_size:.4f} GB)")whileevents_folder_size>self.storage_capacity:folder_to_delete=os.path.join(self.events_folder,min(os.listdir(self.events_folder)))events_folder_size-=StorageManager.delete_folder(folder_to_delete)

4.6 Initial Configuration

remote_camera=RealTimeObjectDetection(frame_width=1280,frame_height=720,camera_number=0,model_name="efficientdet_lite0.tflite",num_threads=4,score_threshold=0.5,max_results=3,category_name_allowlist=["person","dog","cat","umbrella"],folder_name=folder_name,storage_capacity=32,led_pines=[(13,19,26), (16,20,21)],pin_buzzer=12,frequency=5000,duty_cycle=50,fps_frame_count=30,safe_zone=((0,180), (1280,720)))guard_thread=threading.Thread(target=remote_camera.guard,kwargs={"min_video_duration":1,"max_video_duration":60,"max_detection_delay":10,"event_check_interval":10,"safe_zone":True})guard_thread.start()

5. Contributing

6. References