work with image: imgcompare does not support list?

Question

import imgcompare
...

for filename in os.listdir(myPath):
     if filename.endswith(".png"):
         listIm1.append(filename)

for filename2 in os.listdir(myPath2):
     if filename2.endswith(".png"):
         listIm2.append(filename2)

so i fill my two lists with images,now I would like to compare the images of the two lists one by one following the same index, for example:
listIm1[0] with listImg2[0]
listIm1[1] with listImg2[1]
and so on... and that's the code:

for item in listIm1:
        ifSame = imgcompare.is_equal(listIm1[item],listIm2[item],tolerance=2)
        print ifSame

but get the error:

same = imgcompare.is_equal(listIm1[item], listIm2[item], tolerance=2)
TypeError: list indices must be integers, not str

it seems that imgcompare.is_equal() does not work with lists, is there some pythonic expedient to make it works?

Peko Chan · Accepted Answer · 2018-04-18T07:58:30.777

1

since

 if filename2.endswith(".png"):
         listIm2.append(filename2)

for item in listIm1:
        # item = "someimagine.png"
 ifSame = imgcompare.is_equal(listIm1[item],listIm2[item],tolerance=2)
        #listIm1[someimagine.png] is what you are asking => retrun Type Error

I guess you are looking for something like this:

edit:

import os

for filename in os.listdir(myPath):
    if filename2.endswith(".png"):
       img_path = os.path.join(myPath,filename2)  
       listIm2.append(img_path)

listIm1 = [] 
listIm2 = []
for i in range(len(listIm1)):

     ifSame = imgcompare.is_equal(listIm1[i],listIm2[i],tolerance=2)
     print ifSame

and it's better if len(listIm1) == len(listIm2)

edited Apr 18 '18 at 07:58

answered Apr 17 '18 at 21:24

Peko Chan

306
5
15

same error as above: `IOError: [Errno 2] No such file or directory: 'image.png'`but with `for i in range(len(listIm1)): print listIm1[i]` file is found. – mario Letterman Apr 17 '18 at 22:17
I got it, first you have to declare your list in order to append images to them, using `listIm1 = []` and `listIm1 = []`, I have updated the answer – Peko Chan Apr 18 '18 at 05:28
Done, but got the same error `No such file or directory: 'image.png'` even if the file still exists. – mario Letterman Apr 18 '18 at 07:20
ok, now you might need to declare the full path if the images are not in the same directory, somethings like `import os` `os.path.join("your path directory",listIm1[i])` if you print you'll get"c:\yourpath\image.png" and it should work, I've edit the anwser above – Peko Chan Apr 18 '18 at 07:56
I was missing a basic instruction **os.chdir(mypath)**, so your is the correct answer. – mario Letterman Apr 19 '18 at 22:38

Colin Ricardo · Answer 2 · 2018-04-17T21:30:45.077

1

The problem here is that you are trying to get the index of listIm1 by using item. What you want to do is use a range(), like:

for i in range(len(listIm1)):
            ifSame = imgcompare.is_equal(listIm1[i],listIm2[i],tolerance=2)

As @Matt pointed out, this will only work if you know the lists are the same length beforehand, otherwise it will throw an index error.

edited Apr 17 '18 at 21:30

answered Apr 17 '18 at 21:25

Colin Ricardo

16,488
11
47
80

1

Careful! This assumes that listIm1 and listIm2 are the same length! – Matt Apr 17 '18 at 21:28
Yep, that's right. Will update the question to reflect this. – Colin Ricardo Apr 17 '18 at 21:30
@colin with your code have error: `IOError: [Errno 2] No such file or directory: 'image.png'`. But with `for i in range(len(listIm1)): print listIm1[i]`have: image.png, image2.png,... – mario Letterman Apr 17 '18 at 21:53
imgcompare is trying to find a file named 'image.png'. If you are getting that error, that means that there isn't a file named image.png in your current directory. When you are appending to your lists, try using `listIm1.append(os.path.abspath(filename))` and `listIm2.append(os.path.abspath(filename))` instead – Matt Apr 17 '18 at 21:54
It's quite large, a specific section? – mario Letterman Apr 17 '18 at 21:59
`listIm1.append(os.path.abspath(filename))` unfortunately the same error but with the full path: `IOError: [Errno 2] No such file or directory: 'C:\\Users\\a\\Documents\\PycharmProjects\\arduino\\image.png'` – mario Letterman Apr 17 '18 at 22:07
What is `myPath` and `myPath2`? – Colin Ricardo Apr 17 '18 at 22:08

score 0 · Answer 3 · answered Apr 17 '18 at 21:24

0

You are using a for each loop, which grabs each element in your provided list listIm1 and stores it in a temp variable item, you then pass item (which is a string) as an index both of your lists. Indices of a list must be an integer, and that is the error you are getting.

for dir1_file in listIm1:
    for dir2_file in listIm2:
        ifSame = imgcompare.is_equal(dir1_file,dir2_file,tolerance=2)
        print ifSame

This code uses two for each loops, it looks at each element in both of the lists and uses them as the arguments for your method.

answered Apr 17 '18 at 21:24

Matt

973
8
10

I would like to compare images in two lists with same index, this compare the first index of first list with all index of second list and so on, right? – mario Letterman Apr 17 '18 at 22:15
1

You are correct. This will compare every file in dir1 with every file in dir2. If you want to compare two lists using the same index, I would suggest using the answer provided by @colin. You just have to be sure that your two lists are going to be the same size, and be in the order you want. – Matt Apr 17 '18 at 22:26
I tried to use colin's answer but got an error `IOError: [Errno 2] No such file or directory: 'image.png'` even if the file exists. – mario Letterman Apr 18 '18 at 07:15

work with image: imgcompare does not support list?

3 Answers3