我目前正在使用OpenCV和Python编写Bag Of Words分析器。我已经能够从图像中提取信息,学习但问题是训练部分。作为基线,我正在使用this并将其翻译成Python,但我接触到了学习部分,当它应该训练分类器时,它无法说它具有不受支持的响应类型(我假设标签不在格式正确)。我已经尝试了一些但我无法让它工作。有什么想法吗?
import cv2
import os
import numpy as np
dictSize = 1000
retries = 1
flags = cv2.KMEANS_PP_CENTERS
tc = (cv2.TERM_CRITERIA_MAX_ITER, 10, 0.001)
matcher = cv2.DescriptorMatcher_create("FlannBased")
extractor = cv2.DescriptorExtractor_create("SURF")
detector = cv2.FeatureDetector_create("SURF")
bowTrainer = cv2.BOWKMeansTrainer(dictSize,tc,retries,flags)
bowDE = cv2.BOWImgDescriptorExtractor(extractor,matcher)
def extractTrainingVocabulary(path):
global bowTrainer
global extractor
lst=os.listdir(path)
for i in range(0,len(lst)):
if lst[i][0] != ".":
fullPath = path + lst[i]
print "Processing Image " + fullPath
img = cv2.imread(fullPath)
if not (len(img) == 0):
keypoints = detector.detect(img)
if (len(keypoints) == 0):
print "Warning! Could not find any keypoints in image " + fullPath
else:
# Returns 2 vars. The underscore is used to discard the first one
_,features = extractor.compute(img,keypoints)
bowTrainer.add(features)
else:
print "Could not read image " + fullPath
def extractBOWDescriptor(path, descriptors, labels):
global bowTrainer
global extractor
lst=os.listdir(path)
for i in range(0,len(lst)):
if lst[i][0] != ".":
fullPath = path + lst[i]
print "Processing Image " + fullPath
img = cv2.imread(fullPath)
if not (len(img) == 0):
keypoints = detector.detect(img)
if (len(keypoints) == 0):
print "Warning! Could not find any keypoints in image " + fullPath
else:
bowDescriptor = bowDE.compute(img,keypoints)
# descriptors.append(bowDescriptor)
#np.vstack((descriptors,bowDescriptor))
descriptors = np.vstack((descriptors,bowDescriptor))
#labels.append(lst[i][:-4])
labels = np.vstack((labels,float(lst[i][:-4])))
else:
print "Could not read image " + fullPath
return labels, descriptors
def main():
global bowDE
# LEARN
print "Creating Dict..."
extractTrainingVocabulary("./testImages/")
descriptors = bowTrainer.getDescriptors()
print "Clustering " + str(len(descriptors)) + " features. This might take a while..."
dictionary = bowTrainer.cluster()
print "Done clustering"
# EXTRACT
size1 = 0,dictSize
trainingData = np.zeros(size1,dtype=np.float32)
size2 = 0,1
labels = np.zeros(size2,dtype=np.float32)
bowDE.setVocabulary(dictionary)
labels,trainingData = extractBOWDescriptor("./evalImages/",trainingData,labels)
print(trainingData)
print(labels)
print "Training classifier"
size3 = len(trainingData),len(trainingData[0])
responseData = np.zeros(size3,dtype=np.float32)
classifier = cv2.NormalBayesClassifier()
classifier.train(trainingData,labels)
main()
根据@berak的建议,我更改了以下内容:
labels = np.vstack((labels,float(lst[i][:-4])))
- > labels = np.vstack((labels,int(lst[i][:-4])))
labels = np.zeros(size2,dtype=np.float32)
- > labels = np.zeros(size2,dtype=np.int32)
不幸的是仍然失败。现在我得到以下内容:
error: (-5) There is only a single class in function cvPreprocessCategoricalResponses