deep-person-reid/torchreid/utils/GPU-Re-Ranking/gnn_reranking.py

60 lines
1.8 KiB
Python

"""
Understanding Image Retrieval Re-Ranking: A Graph Neural Network Perspective
Xuanmeng Zhang, Minyue Jiang, Zhedong Zheng, Xiao Tan, Errui Ding, Yi Yang
Project Page : https://github.com/Xuanmeng-Zhang/gnn-re-ranking
Paper: https://arxiv.org/abs/2012.07620v2
======================================================================
On the Market-1501 dataset, we accelerate the re-ranking processing from 89.2s to 9.4ms
with one K40m GPU, facilitating the real-time post-processing. Similarly, we observe
that our method achieves comparable or even better retrieval results on the other four
image retrieval benchmarks, i.e., VeRi-776, Oxford-5k, Paris-6k and University-1652,
with limited time cost.
"""
import numpy as np
import torch
import gnn_propagate
import build_adjacency_matrix
from utils import *
def gnn_reranking(X_q, X_g, k1, k2):
query_num, gallery_num = X_q.shape[0], X_g.shape[0]
X_u = torch.cat((X_q, X_g), axis=0)
original_score = torch.mm(X_u, X_u.t())
del X_u, X_q, X_g
# initial ranking list
S, initial_rank = original_score.topk(
k=k1, dim=-1, largest=True, sorted=True
)
# stage 1
A = build_adjacency_matrix.forward(initial_rank.float())
S = S * S
# stage 2
if k2 != 1:
for i in range(2):
A = A + A.T
A = gnn_propagate.forward(
A, initial_rank[:, :k2].contiguous().float(),
S[:, :k2].contiguous().float()
)
A_norm = torch.norm(A, p=2, dim=1, keepdim=True)
A = A.div(A_norm.expand_as(A))
cosine_similarity = torch.mm(A[:query_num, ], A[query_num:, ].t())
del A, S
L = torch.sort(-cosine_similarity, dim=1)[1]
L = L.data.cpu().numpy()
return L