问题描述
我正在尝试使用 BRISK+FREAK
error: OpenCV(4.1.2) /io/opencv/modules/features2d/src/draw.cpp:225: error: (-215:Assertion Failed) i1 >= 0 && i1
import cv2
import numpy as np
import matplotlib.pyplot as plt
trainImg = cv2.imread('/content/img1.JPG')
trainImg_gray = cv2.cvtColor(trainImg,cv2.COLOR_BGR2GRAY)
queryImg = cv2.imread('/content/img2.JPG')
queryImg_gray = cv2.cvtColor(queryImg,cv2.COLOR_BGR2GRAY)
def detectAndDescribe(image,method=None):
"""
Compute key points and feature descriptors using an specific method
"""
descriptor = cv2.BRISK_create()
# get keypoints and descriptors
(kps,features) = descriptor.detectAndCompute(image,None)
freakExtractor = cv2.xfeatures2d.FREAK_create()
keypoints,descriptors= freakExtractor.compute(image,kps)
return (keypoints,features)
method = 'brisk'
feature_extractor = 'brisk'
feature_matching = 'bf'
kpsA,featuresA = detectAndDescribe(trainImg_gray,method=feature_extractor)
kpsB,featuresB = detectAndDescribe(queryImg_gray,method=feature_extractor)
"Create and return a Matcher Object"
createMatcher = lambda crossCheck : cv2.BFMatcher(cv2.norM_HAMMING,crossCheck=crossCheck)
def matchKeyPointsBF(featuresA,featuresB,method):
bf = createMatcher(crossCheck=True)
# Match descriptors.
best_matches = bf.match(featuresA,featuresB)
# Sort the features in order of distance.
# The points with small distance (more similarity) are ordered first in the vector
rawMatches = sorted(best_matches,key = lambda x:x.distance)
print("Raw matches (Brute force):",len(rawMatches))
return rawMatches
print("Using: {} feature matcher".format(feature_matching))
fig = plt.figure(figsize=(20,8))
matches = matchKeyPointsBF(featuresA,method=feature_extractor)
img3 = cv2.drawMatches(trainImg,kpsA,queryImg,kpsB,matches,None,flags=cv2.DrawMatchesFlags_NOT_DRAW_SINGLE_POINTS)
plt.imshow(img3)
plt.show()
这是我得到的完整错误
使用:bf 特征匹配器原始匹配(蛮力):1967 -------------------------------------------------- ------------------------- 错误回溯(最近调用 最后) 在 () 4 5 匹配 = matchKeyPointsBF(featuresA,method=feature_extractor) ----> 6 img3 = cv2.drawMatches(trainImg,flags=cv2.DrawMatchesFlags_NOT_DRAW_SINGLE_POINTS) 7 8
错误:OpenCV(4.1.2) /io/opencv/modules/features2d/src/draw.cpp:225: 错误:(-215:断言失败)i1 >= 0 && i1
似乎不知道这里出了什么问题,发现这个 OpenCV Sift/Surf/Orb : drawMatch function is not working well 无法理解如何纠正这个
解决方法
您将 FREAK 的 keypoints
与 BRISK 的 features
混合:
仔细看detectAndDescribe
的代码:
def detectAndDescribe(image,method=None):
"""
Compute key points and feature descriptors using an specific method
"""
descriptor = cv2.BRISK_create()
# get keypoints and descriptors
(kps,features) = descriptor.detectAndCompute(image,None)
freakExtractor = cv2.xfeatures2d.FREAK_create()
keypoints,descriptors= freakExtractor.compute(image,kps)
return (keypoints,features) # <------ keypoints from freakExtractor.compute and features from descriptor.detectAndCompute
报告的异常看起来是随机的,所以很难找到问题...
您可以按如下方式实现 detectAndDescribe
:
- 使用 BRISK 检测关键点
- 将检测到的关键点传递给 FREAK
- 返回
freakExtractor.compute
的输出
建议实施:
def detectAndDescribe(image,method=None):
descriptor = cv2.BRISK_create()
kps = descriptor.detect(image) # kps,features = descriptor.detectAndCompute(image,None)
freakExtractor = cv2.xfeatures2d.FREAK_create()
keypoints,kps)
return (keypoints,descriptors)