Cider Metrics for image captioning

I am working on my image captioning process. For evaluation, I am using the pycocoevalcap package (GitHub - salaniz/pycocoevalcap: Python 3 support for the MS COCO caption evaluation tools), for the Cider metrics, i am writing some tests. If there is only one pair of groundtruth and prediction, cider gives 0 even though they are completely the same. But if there is two or even more pair, it is not 0 anymore. Why is that? I use the code below to test.

'''
Need java 1.8
Package:
pycocoevalcap
'''
from bleu.bleu import Bleu
from meteor.meteor import Meteor
from rouge.rouge import Rouge
from cider.cider import Cider
from spice.spice import Spice
import os
import sys
import ssl
class Scorer():
    def __init__(self,ref,gt):
        self.ref = ref
        self.gt = gt
        print('setting up scorers...')
        self.word_based_scorers = [
            (Bleu(4), ["Bleu_1", "Bleu_2", "Bleu_3", "Bleu_4"]),
            (Meteor(),"METEOR"),
            (Rouge(), "ROUGE_L"),
            (Cider(), "CIDEr"),
            # (Spice(), "SPICE"),
            ]


        
    def compute_scores(self):
        total_scores = {
            "Bleu1":[],
            "Bleu2":[],
            "Bleu3":[],
            "Bleu4":[],
            "METEOR":[],
            "ROUGE_L":[],
            "CIDEr":[],
            "SPICE":[]
        
        }

        for scorer, method in self.word_based_scorers:
            #print('computing %s score...'%(scorer.method()))
            # print(scorer)
            # print(method)
            score, scores = scorer.compute_score(self.ref, self.gt)
    
            if type(method) == list:
            #    for sc, scs, m in zip(score, scores, method):
                    # print("----------Bleu----------")
                    # print("%s: %0.3f"%(m, sc))
                total_scores["Bleu1"].append(score[0])
                total_scores["Bleu2"].append(score[1])
                total_scores["Bleu3"].append(score[2])
                total_scores["Bleu4"].append(score[3])
            else:
                # print("----------Other----------")
                # print("%s: %0.3f"%(method, score))
                # print(f"method is {method} total is {total_scores}")
                total_scores[method].append(score)
        # print(total_scores)
        
        # print('*****DONE*****')

        return total_scores
    def compute_scores_iterative(self):


        total_scores = {
            "Bleu1":[],
            "Bleu2":[],
            "Bleu3":[],
            "Bleu4":[],
            "METEOR":[],
            "ROUGE_L":[],
            "CIDEr":[],
            "SPICE":[]
        
        }

        for key in self.ref:
            
            curr_ref = {key:self.ref[key]}
            curr_gt = {key:self.gt[key]}

            for scorer, method in self.word_based_scorers:
                #print('computing %s score...'%(scorer.method()))
                # print(scorer)
                # print(method)
                #print(curr_gt)
                score, _ = scorer.compute_score(curr_ref, curr_gt)
                # print(score)
                if type(method) == list:
                    # for sc, scs, m in zip(score, scores, method):
                        # print("----------Bleu----------")
                        # print("%s: %0.3f"%(m, sc))
                    total_scores["Bleu1"].append(score[0])
                    total_scores["Bleu2"].append(score[1])
                    total_scores["Bleu3"].append(score[2])
                    total_scores["Bleu4"].append(score[3])
                else:
                    # print("----------Other----------")
                    # print("%s: %0.3f"%(method, score))
                    # print(f"method is {method} score is {score}")
                    total_scores[method].append(score)
                # print(score)
        
        # print('*****DONE*****')
        # print(total_scores)
        return total_scores
        # for key,value in total_scores.items():
        #     print('{}:{}'.format(key,value))

if __name__ == '__main__':
    import numpy as np
    ssl._create_default_https_context = ssl._create_unverified_context # Use it to solve SSL 


    ref = {'1': ['go down the stairs all the way and stop at the bottom'],}
    gen = {'1': ['go down the stairs all the way and stop at the bottom'],}
    scorer = Scorer(ref,gen)
    tol_scores = scorer.compute_scores()
    print(tol_scores)

Hello dear Peter, I have this problem too. it’s cause the Cider score uses TF-IDF. but I couldn’t find any solution for it. Did you find a solution for it?

Hi,
I ended up not solving this issue. Did not see any good explanation for this issue. I am sorry.

Does anyone got the solution