项目场景：在做扫描匹配的时候，使用Vs2022发生list index out of range的报错

问题描述：

folder = argv[1]
query = cv2.imread(join(folder,"tattoo_seed.jpg"), 0)

原因分析：扫描的路径没有写清晰，导致VS也不知道去哪索引，所以发生报错；但是在VS2022也无法输入路径，所以只有在命令控制里面输入路径。

解决方案：win+r后输入cmd，进入这个界面。

然后输入python “你python代码存在的位置” “你扫描图片或视频的位置”
我输入的是
python “D:\opencv bob\pycv-master\chapter6\scan_for_matches.py” “D:\opencv bob\pycv-master\chapter6\anchors”

最后按下回车键，代码开始运行，代码运行结果就是相似的纹身输出is a match；不相似的输出is not a match。

接下来贴出我的代码，有兴趣的同学可以拿走：`

from os.path import join
from os import walk
import numpy as np
import cv2
from sys import argv

# create an array of filenames
folder = argv[1]
query = cv2.imread(join(folder,"tattoo_seed.jpg"), 0)

# create files, images, descriptors globals
files = []
images = []
descriptors = []
for (dirpath, dirnames, filenames) in walk(folder):
  files.extend(filenames)
  for f in files:
    if f.endswith("npy") and f != "tattoo_seed.npy":
      descriptors.append(f)
  print (descriptors)

# create the sift detector
sift = cv2.xfeatures2d.SIFT_create()
query_kp, query_ds = sift.detectAndCompute(query, None)

# create FLANN matcher
FLANN_INDEX_KDTREE = 0
index_params = dict(algorithm = FLANN_INDEX_KDTREE, trees = 5)
search_params = dict(checks = 50)
flann = cv2.FlannBasedMatcher(index_params, search_params)

# minimum number of matches
MIN_MATCH_COUNT = 10

potential_culprits = {
    }

print (">> Initiating picture scan...")
for d in descriptors:
  print( "--------- analyzing %s for matches ------------" % d)
  matches = flann.knnMatch(query_ds, np.load(join(folder, d)), k =2)
  good = []
  for m,n in matches:
      if m.distance < 0.7*n.distance:
          good.append(m)
  if len(good) > MIN_MATCH_COUNT:
    
    print ("%s is a match! (%d)" % (d, len(good)))
  else:
    print( "%s is not a match" % d)
  potential_culprits[d] = len(good)

max_matches = None
potential_suspect = None
for culprit, matches in potential_culprits.iteritems():
  if max_matches == None or matches > max_matches:
    max_matches = matches
    potential_suspect = culprit

print ("potential suspect is %s" % potential_suspect.replace("npy", "").upper())

在代码里有cv2.xfeatures2d.SIFT_create()这个函数，
如果在这发生报错，可以看看我的另一篇博客，有解决办法。over！