object_detection_picam.py

# import the necessary packages
from picamera.array import PiRGBArray
from picamera import PiCamera
import time
import cv2 as cv
import numpy as np
import os
 
# initialize the camera and grab a reference to the raw camera capture
camera = PiCamera()
camera.resolution = (640, 480)
camera.framerate = 32
rawCapture = PiRGBArray(camera, size=(640, 480))
 
# allow the camera to warmup
time.sleep(0.1)

#Setting up frames
openingKernel = cv.getStructuringElement(cv.MORPH_RECT, (10, 10)) # Make a kernel for closing (noise removal)
openingKernelRed = cv.getStructuringElement(cv.MORPH_RECT, (2, 2))

# define range of blue color in HSV
# Range for green in HSV
# lower = 40 40 40
# upper = 80 255 255
# TODO: Tweek these values to detect all ranges of color properly

# Values calculated from: https://alloyui.com/examples/color-picker/hsv
# Limits for green range
lower_green = np.array([37, 80, 40])
upper_green = np.array([95, 255, 255])

# Limits for blue range
lower_blue = np.array([100, 80, 50])
upper_blue = np.array([125, 255, 255])

# Limits for yellow range
lower_yellow = np.array([20, 80, 40])
upper_yellow = np.array([35, 255, 255])

# Limits for red
lower_red = np.array([170, 80, 40])
upper_red = np.array([180, 255, 255])
 
# capture frames from the camera
for frame in camera.capture_continuous(rawCapture, format="bgr", use_video_port=True):
    os.system('clear')
	# grab the raw NumPy array representing the image, then initialize the timestamp
	# and occupied/unoccupied text
    frame = frame.array
    hsv = cv.cvtColor(frame, cv.COLOR_BGR2HSV) # Take each frame

    # Threshold the HSV image to get only desired colors
    maskGreen = cv.inRange(hsv, lower_green, upper_green)
    maskBlue = cv.inRange(hsv, lower_blue, upper_blue)
    maskYellow = cv.inRange(hsv, lower_yellow, upper_yellow)
    maskRed = cv.inRange(hsv, lower_red, upper_red)


    # # Clear noise from mask by opening it, then apply gaussian blur
    maskGreen = cv.morphologyEx(maskGreen, cv.MORPH_OPEN, openingKernel)
    maskGreen = cv.GaussianBlur(maskGreen, (5, 5), 0)

    maskBlue = cv.morphologyEx(maskBlue, cv.MORPH_OPEN, openingKernel)
    maskBlue = cv.GaussianBlur(maskBlue, (5, 5), 0)

    maskYellow = cv.morphologyEx(maskYellow, cv.MORPH_OPEN, openingKernel)
    maskYellow = cv.GaussianBlur(maskYellow, (5, 5), 0)

    maskRed = cv.morphologyEx(maskRed, cv.MORPH_OPEN, openingKernelRed)
    maskRed = cv.GaussianBlur(maskRed, (5, 5), 0)

    # Using threshold incase the image is not binary, can be removed
    _, threshGreen = cv.threshold(maskGreen, 100, 255, cv.THRESH_BINARY)
    _, threshBlue = cv.threshold(maskBlue, 100, 255, cv.THRESH_BINARY)
    _, threshYellow = cv.threshold(maskYellow, 100, 255, cv.THRESH_BINARY)
    _, threshRed = cv.threshold(maskRed, 100, 255, cv.THRESH_BINARY)

    _,contoursGreen, _ = cv.findContours(threshGreen, cv.RETR_TREE, cv.CHAIN_APPROX_SIMPLE)
    _,contoursBlue, _ = cv.findContours(threshBlue, cv.RETR_TREE, cv.CHAIN_APPROX_SIMPLE)
    _,contoursYellow, _ = cv.findContours(threshYellow, cv.RETR_TREE, cv.CHAIN_APPROX_SIMPLE)
    _,contoursRed, _ = cv.findContours(threshRed, cv.RETR_TREE, cv.CHAIN_APPROX_SIMPLE)

    # Bitwise-AND mask and original image
    mask = cv.bitwise_or(maskBlue, maskGreen)
    mask = cv.bitwise_or(mask, maskYellow)
    mask=cv.bitwise_or(mask, maskRed)
    res = cv.bitwise_and(frame, frame, mask=mask)

    numGreen = len(contoursGreen)
    numRed=len(contoursRed)
    numBlue=len(contoursBlue)
    numYellow=len(contoursYellow)
    if(numBlue>5):
        print("Bottle: True")
    else:
        print("Bottle:False")
    if(numRed>400):
        print("Box: True")
    else:
        print("Box:False")  
    if(numGreen>4):
        print("Ball: True")
    else:
        print("Ball:False")
    
    if(numYellow>2):
        print("Disc: True")
    else:
        print("Disc:False")
    
    # for c in contoursGreen:
    #   # To avoid false-positives, the green object should be sufficiently big
    #   if cv.contourArea(c) > 700:
    #     # Calculate center of mass to put the text
    #     M = cv.moments(c)
    #     cX = int(M["m10"] / M["m00"])
    #     cY = int(M["m01"] / M["m00"])

    #     cv.circle(frame, (cX, cY), 7, (255, 255, 255), -1)
    #     cv.putText(frame, "green ball", (cX - 10, cY - 10), cv.FONT_HERSHEY_SIMPLEX, 0.5, (255, 255, 255), 2)
    #     cv.drawContours(res, [c], -1, (255, 0, 255), 3)

    # for c in contoursBlue:
    #   # To avoid false-positives, the green object should be sufficiently big
    #   if cv.contourArea(c) > 1000:
    #     # Calculate center of mass to put the text
    #     M = cv.moments(c)
    #     cX = int(M["m10"] / M["m00"])
    #     cY = int(M["m01"] / M["m00"])

    #     cv.circle(frame, (cX, cY), 7, (255, 255, 255), -1)
    #     cv.putText(frame, "bottle", (cX - 10, cY - 10), cv.FONT_HERSHEY_SIMPLEX, 0.5, (255, 255, 255), 2)
    #     cv.drawContours(res, [c], -1, (255, 0, 255), 3)

    # for c in contoursYellow:
    #   # To avoid false-positives, the green object should be sufficiently big
    #   if cv.contourArea(c) > 1000:
    #     # Calculate center of mass to put the text
    #     M = cv.moments(c)
    #     cX = int(M["m10"] / M["m00"])
    #     cY = int(M["m01"] / M["m00"])

    #     cv.circle(frame, (cX, cY), 7, (255, 255, 255), -1)
    #     cv.putText(frame, "yellow disk", (cX - 10, cY - 10), cv.FONT_HERSHEY_SIMPLEX, 0.5, (255, 255, 255), 2)
    #     cv.drawContours(res, [c], -1, (255, 0, 255), 3)

    # for c in contoursRed:
    # # To avoid false-positives, the green object should be sufficiently big
    #   if cv.contourArea(c) > 1000:
    #     # Calculate center of mass to put the text
    #     M = cv.moments(c)
    #     cX = int(M["m10"] / M["m00"])
    #     cY = int(M["m01"] / M["m00"])

    #     cv.circle(frame, (cX, cY), 7, (255, 255, 255), -1)
    #     cv.putText(frame, "red box", (cX - 10, cY - 10), cv.FONT_HERSHEY_SIMPLEX, 0.5, (255, 255, 255), 2)
    #     cv.drawContours(res, [c], -1, (255, 0, 255), 3)
    # # Show the image and the result
    # cv.imshow('res', res)
    # cv.imshow('blue', maskBlue)
    # cv.imshow('green', maskGreen)
    # cv.imshow('yellow', maskYellow)
    # cv.imshow('red', maskRed)
    # cv.imshow('res', res)
    # EXIT if 'esc' key is pressed
    k = cv.waitKey(5) & 0xFF
    #clear the stream for the next frame
    rawCapture.truncate(0)
    if k == 27:
        break