我正在尝试将python代码应用于目录中的所有文件，但这给我一个错误

Question

I am trying to apply a python code to all the files in a directory but it gives me a error:

test_image = cv2.imread(sys.argv[1],0)
   IndexError: list index out of range 

I dont know what to change I tried few things but it does not help so if someone can help with this that would be great. And using stackoverflow for the first time, just to see how it works.

import sys
import cv2
import os
import numpy as np
from utils import pointsInsideCircle, compare, zigzag
from math import pi as PI

filepath = os.path.join("/Users/ssm/Desktop/X/1/Original Images",     "*.tif")
W   = 8             #block size for comparision
Dsim    = 0.1           #threshold for symmetry
Nd  = 25            #nearest block

quadrants_points = pointsInsideCircle(W/4)  #(i,j) position of blocks      which are partially/completely inside circle of radius W/2
zigzag_points = zigzag(W/2)
test_image = cv2.imread(sys.argv[1],0)
height,width = test_image.shape[:2]
#print (height,width)
vectors_list = []
for j in range(0,height-W+1):
    for i in range(0,width-W+1):
        block = test_image[j:j+W,i:i+W]
        dct_block =  cv2.dct(np.float32(block))
        feature_block = [[],[],[],[]]
        for index,coeff_list in enumerate(zigzag_points):
            for coeff in coeff_list:
                 feature_block[index].append(dct_block[coeff[0],coeff[1]])

        feature_block_np = np.array(feature_block)

        feature_vector = []
        for quadrant,points in quadrants_points.iteritems():
            summ = 0
        for point in points:
            summ = summ + feature_block_np[point[0],point[1]]
        feature_vector.append(summ/PI)
    vectors_list.append(np.array(feature_vector))

vectors_list2 = cv2.sort(np.array(vectors_list),cv2.SORT_EVERY_ROW)
print "vectors calculated"
import json
with open('data.json', 'w') as outfile:
    json.dump(vectors_list2.tolist(), outfile)


i=0
blocks = []
for i in range(0,len(vectors_list)):
    if i%width == 0:
        print i/width
    posA = [i/width,i%width]
    j = i+1
    for j in range(i+1,len(vectors_list)):
        posB = [j/width,j%width]
        if compare(vectors_list[i],vectors_list[j],posA,posB,Dsim,Nd):
            print (posA,posB)
            blocks.append([posA,posB])

output_image = cv2.imread(sys.argv[1],1)
for block in blocks:
    x1 = block[0][0]
    x1_8 = block[0][0]+W
    y1 = block[0][1]
    y1_8 = block[0][1]+W

    output_image[x1:x1_8,y1:y1_8] = [0,0,255]

    x2 = block[1][0]
    x2_8 = block[1][0]+W
    y2 = block[1][1]
    y2_8 = block[1][1]+W

    output_image[x2:x2_8,y2:y2_8]=[0,255,0]

cv2.imwrite("output.jpg",output_image)


print "feature vectors extracted"

Answer 1

test_image = cv2.imread(sys.argv[1],0)

is checking the list provided by the commandline for a file name. For example if you invoked this script with:

$python myprog.py afilename.xxx

sys.argv would be ['myprog', 'afilename.xxx'] , and this imread line would load an image from afilename.xxx .

If you don't provide that filename, sys.argv will only have the script name, and sys.argv[1] will raise this error.