Images.py

# import the necessary packages
import numpy as np
import argparse
import time
import cv2
import os

# construct the argument parse and parse the arguments
ap = argparse.ArgumentParser()
ap.add_argument("-i", "--image", required=True,
	help="path to input image")
ap.add_argument("-cfg", "--config", type=str, default="Configurations\\face_mask_detection.cfg",
	help="path to input image")
ap.add_argument("-n", "--names", type=str, default="Configurations\\face_mask_detection.names",
	help="path to input image")	
ap.add_argument("-c", "--confidence", type=float, default=0.5,
	help="minimum probability to filter weak detections")
ap.add_argument("-t", "--threshold", type=float, default=0.5,
	help="threshold when applying non-maxima suppression")
args = vars(ap.parse_args())

# load the COCO class labels our YOLO model was trained on
classes = []
with open(args["names"], "r") as f:
    classes = [line.strip() for line in f.readlines()]

# initialize a list of colors to represent each possible class label
np.random.seed(42)
COLORS = [[0, 255, 0], [0, 0, 255], [0, 255, 255]]

# derive the paths to the YOLO weights and model configuration
root = "..\\Phase 2 - YOLOv3\\darknet\\"
weightsPath = root + "backup\\face_mask_detection_best.weights"
configPath = args["config"]
# load our YOLO object detector trained on custom dataset (3 classes)
print("[INFO] loading YOLO from disk...")
net = cv2.dnn.readNetFromDarknet(configPath, weightsPath)

# load our input image and grab its spatial dimensions
image = cv2.imread(args["image"])
(H, W) = image.shape[:2]
# determine only the *output* layer names that we need from YOLO
ln = net.getLayerNames()
ln = [ln[i[0] - 1] for i in net.getUnconnectedOutLayers()]
# construct a blob from the input image and then perform a forward
# pass of the YOLO object detector, giving us our bounding boxes and
# associated probabilities
blob = cv2.dnn.blobFromImage(image, 1 / 255.0, (416, 416),
	swapRB=True, crop=False)
net.setInput(blob)
start = time.time()
layerOutputs = net.forward(ln)
end = time.time()
# show timing information on YOLO
print("[INFO] YOLO took {:.6f} seconds".format(end - start))

# initialize our lists of detected bounding boxes, confidences, and
# class IDs, respectively
boxes = []
confidences = []
classIDs = []

# loop over each of the layer outputs
for output in layerOutputs:
	# loop over each of the detections
	for detection in output:
		# extract the class ID and confidence (i.e., probability) of
		# the current object detection
		scores = detection[5:]
		classID = np.argmax(scores)
		confidence = scores[classID]
		# filter out weak predictions by ensuring the detected
		# probability is greater than the minimum probability
		if confidence > args["confidence"]:
			# scale the bounding box coordinates back relative to the
			# size of the image, keeping in mind that YOLO actually
			# returns the center (x, y)-coordinates of the bounding
			# box followed by the boxes' width and height
			box = detection[0:4] * np.array([W, H, W, H])
			(centerX, centerY, width, height) = box.astype("int")
			# use the center (x, y)-coordinates to derive the top and
			# and left corner of the bounding box
			x = int(centerX - (width / 2))
			y = int(centerY - (height / 2))
			# update our list of bounding box coordinates, confidences,
			# and class IDs
			boxes.append([x, y, int(width), int(height)])
			confidences.append(float(confidence))
			classIDs.append(classID)

# apply non-maxima suppression to suppress weak, overlapping bounding
# boxes
idxs = cv2.dnn.NMSBoxes(boxes, confidences, args["confidence"],
	args["threshold"])

# ensure at least one detection exists
if len(idxs) > 0:
	# loop over the indexes we are keeping
	for i in idxs.flatten():
		# extract the bounding box coordinates
		(x, y) = (boxes[i][0], boxes[i][1])
		(w, h) = (boxes[i][2], boxes[i][3])
		# draw a bounding box rectangle and label on the image
		color = [int(c) for c in COLORS[classIDs[i]]]
		cv2.rectangle(image, (x, y), (x + w, y + h), color, 1)
		text = "{}: {:.4f}".format(classes[classIDs[i]], confidences[i])
		cv2.putText(image, text, (x, y - 5), cv2.FONT_HERSHEY_SIMPLEX,
			0.5, color, 1)

cv2.namedWindow("Image", cv2.WINDOW_NORMAL)

# show the output image
cv2.imshow("Image", image)
cv2.waitKey(0)