我在使用Python,OpenCV 3.1和HOG进行有用的检测时遇到了问题。虽然我的工作代码无误地执行,但训练后的HOG/SVM组合无法在测试图像上检测到。使用OpenCV在Python中进行HOG培训和检测
从OpenCV示例和其他堆栈溢出讨论我已经开发了以下方法。
win_size = (64, 64)
block_size = (16, 16)
block_stride = (8, 8)
cell_size = (8, 8)
nbins = 9
deriv_aperture = 1
win_sigma = 4.
histogram_norm_type = 0
l2_hys_threshold = 2.0000000000000001e-01
gamma_correction = 0
nlevels = 64
hog = cv2.HOGDescriptor(win_size,
block_size,
block_stride,
cell_size,
nbins,
deriv_aperture,
win_sigma,
histogram_norm_type,
l2_hys_threshold,
gamma_correction,
nlevels)
window_stride = (8, 8)
padding = (8, 8)
locations = ((0, 0),)
histograms = []
# not showing the loop here but
# create histograms for 600 positive and 600 negative images
# all images are of size 64x64
histograms.append(np.transpose(hog.compute(roi, window_stride, padding, locations)))
training_data = np.concatenate(histograms)
classifications = np.array([1] * 600 + [0] * 600)
svm = cv2.ml.SVM_create()
svm.setType(cv2.ml.SVM_C_SVC)
svm.setKernel(cv2.ml.SVM_LINEAR)
svm.setC(0.01)
svm.setTermCriteria((cv2.TermCriteria_MAX_ITER, 100, 1e-6))
svm.train(training_data, cv2.ml.ROW_SAMPLE, classifications)
# testing
test_img = cv2.imread('test_image.jpg')
svmvec = svm.getSupportVectors()[0]
rho = -svm.getDecisionFunction(0)[0]
svmvec = np.append(svmvec, rho)
hog.setSVMDetector(svmvec)
found, w = hog.detectMultiScale(test_img)
在每一个试验中,found
是在图像中居中的单一矩形和不位于其中正位于测试图像英寸
我已经尝试了许多基于堆栈溢出回答和其他OpenCV示例和讨论的不同参数组合。他们都没有改变结果。
详细和组织良好的问题解释应该奖励。我可以问你为什么只使用** svm.getSupportVectors()[0] **的原因吗? – 3yanlis1bos