This is my project tree:
car_detector |-- detector.py |-- __init__.py |-- non_maximum.py |-- pyramid.py |-- README.md |-- sliding_window.py
This my code for detector.py:
import cv2
import numpy as np
datapath = '/home/pi/CarData/TrainImages'
SAMPLES = 400
def path(cls,i):
return "%s/%s%d.pgm" % (datapath,cls,i+1)
def get_flann_matcher():
flann_params = dict(algorithm = 1, trees = 5)
return cv2.FlannBasedMatcher(flann_params, {})
def get_bow_extractor(extract,flann):
return cv2.BOWImgDescriptorExtractor(extract, flann)
def get_extract_detect():
return cv2.xfeatures2d.SIFT_create(), cv2.xfeatures2d.SIFT_create()
def extract_sift(fn,extractor,detector):
im = cv2.imread(fn,0)
return extractor.compute(im, detector.detect(im))[1]
def bow_features(img, extractor_bow, detector):
return extractor_bow.compute(img, detector.detect(img))
def car_detector():
pos, neg = "pos-", "neg-"
detect, extract = get_extract_detect()
flann = get_flann_matcher()
print("Building BOWKMeansTrainer...")
bow_kmeans_trainer = cv2.BOWKMeansTrainer(1000)
extract_bow = cv2.BOWImgDescriptorExtractor(extract,flann)
print("Adding features to trainer...")
for i in range(SAMPLES):
print(i)
bow_kmeans_trainer.add(extract_sift(path(pos,i),extract,detect))
bow_kmeans_trainer.add(extract_sift(path(neg,i),extract,detect))
voc = bow_kmeans_trainer.cluster()
extract_bow.setVocabulary(voc)
traindata, trainlabels = [], []
print("Adding to train data...")
for i in range(SAMPLES):
print(i)
traindata.extend(bow_features(cv2.imread(path(pos,i),0), extract_bow, detect))
trainlabels.append(1)
traindata.extend(bow_features(cv2.imread(path(neg,i),0), extract_bow, detect))
trainlabels.append(-1)
svm = cv2.ml.SVM_create()
cvm.setType(cv2.ml.SVM_C_SVC)
svm.setGamma(0.5)
svm.setC(30)
svm.setKernel(cv2.ml.SVM_RBF)
svm.train(np.array(traindata), cv2.ml.ROW_SAMPLE,np.array(trainlabels))
return svm, extract_bow
I keep on getting this error:
bow_kmeans_trainer.add(extract_sift(path(neg,i),extract,detect))
cv2.error: OpenCV(4.1.0) /home/pi/opencv/opencv-4.1.0/modules/features2d/src/bagofwords.cpp:55: error: (-215:Assertion failed) !_descriptors.empty() in function 'add'
I know it's something to do with the the OpenCV I downloaded (OpenCV 4.1.0).
