Pattern Matching Support

Question

I'm trying to create a system for pattern matching in images and this is what I have currently:

def ratio(x,y):
    return 1/(x*y) 

def memory(image):
    i__ia=0
    l__img = Image.open(image)
    l__pix = l__img.load()
    l__width = l__img.width
    l__height = l__img.height
    s__img = None
    l__r = 0
    l__b = 0
    l__g = 0
    s__str = None
    s__per = 0 
    for filename in os.listdir("Memory/"):
        i__ia+=1
        m__percent = 0
        p__r = 0
        p__g = 0
        p__b = 0
        f = os.path.join("Memory/", filename)
        m__img = Image.open(f)
        m__pix = m__img.load()
        for l__w in range(0,l__width,1):
            for l__h in range(0,l__height,1):
                try:
                    if m__pix[l__w,l__h] == l__pix[l__w,l__h]:
                        temp = m__pix[l__w,l__h]
                        a__percent = ratio(l__width,l__height)
                        p__r+=temp[0]
                        p__g+=temp[1]
                        p__b+=temp[2]
                        m__percent+=a__percent
                    else:
                        p__r+=temp[0]
                        p__g+=temp[1]
                        p__b+=temp[2]
                        a__percent = ratio(l__width,l__height)
                        m__percent-=a__percent
                except:
                    a__percent = ratio(l__width,l__height)
                    m__percent-=a__percent
                    pass

        if m__percent > s__per and p__r >= l__r and p__b >= l__b and p__g >= l__g:
            s__per = m__percent
            s__img = m__img
            s__str = f
            l__r = (1/(p__r+p__b+p__g))*p__r
            l__b = (1/(p__r+p__b+p__g))*p__b
            l__g = (1/(p__r+p__b+p__g))*p__g
        else:
            m__percent = 0
                    
    

    if s__per > 0.8:
        return True, s__per, s__str,l__r,l__g,l__b
    else: 
        try:
            tes = Image.open(image)
            tes.save(f'Memory/unknown{i__ia}.png')
            return False, s__per, s__str,l__r,l__g,l__b
        except:
            pass

My end goal is to find differences between pictures, find similarities, be able to classify the image based on how similar it is to other images.

Currently, all I've made is something that can tell how similar two images are based on their color differences and size differences.

I'm having trouble thinking of a way to detect if there is a similar shape or pattern in the image.

Any help is greatly appreciated!