详细解释一下这段代码，每一句给出详细注解：for k in kpts.keys(): kpts[k] = np.round(np.concatenate(kpts[k], axis=0)) unique_kpts = {} unique_match_idxs = {} for k in kpts.keys(): uniq_kps, uniq_reverse_idxs = torch.unique(torch.from_numpy(kpts[k].astype(np.float32)), dim=0, return_inverse=True) unique_match_idxs[k] = uniq_reverse_idxs unique_kpts[k] = uniq_kps.numpy() with h5py.File(f"{feature_dir}/keypoints.h5", mode='w') as f_kp: for k, kpts1 in unique_kpts.items(): f_kp[k] = kpts1 out_match = defaultdict(dict) for k1, group in match_indexes.items(): for k2, m in group.items(): m2 = deepcopy(m) m2[:,0] = unique_match_idxs[k1][m2[:,0]] m2[:,1] = unique_match_idxs[k2][m2[:,1]] mkpts = np.concatenate([unique_kpts[k1][m2[:,0]], unique_kpts[k2][m2[:,1]]], axis=1) unique_idxs_current = get_unique_idxs(torch.from_numpy(mkpts), dim=0) m2_semiclean = m2[unique_idxs_current] unique_idxs_current1 = get_unique_idxs(m2_semiclean[:, 0], dim=0) m2_semiclean = m2_semiclean[unique_idxs_current1] unique_idxs_current2 = get_unique_idxs(m2_semiclean[:, 1], dim=0) m2_semiclean2 = m2_semiclean[unique_idxs_current2] out_match[k1][k2] = m2_semiclean2.numpy() with h5py.File(f"{feature_dir}/matches.h5", mode='w') as f_match: for k1, gr in out_match.items(): group = f_match.require_group(k1) for k2, match in gr.items(): group[k2] = match

这段代码实现了对关键点的处理和匹配，最终保存在文件中。具体的注释如下：

# 对每个图像的关键点进行合并，并且四舍五入
for k in kpts.keys():
    kpts[k] = np.round(np.concatenate(kpts[k], axis=0))
# 初始化两个字典
unique_kpts = {}
unique_match_idxs = {}

# 对于每个图像的关键点进行去重，得到unique_kpts和unique_match_idxs
for k in kpts.keys():
    uniq_kps, uniq_reverse_idxs = torch.unique(torch.from_numpy(kpts[k].astype(np.float32)), dim=0, return_inverse=True)
    unique_match_idxs[k] = uniq_reverse_idxs
    unique_kpts[k] = uniq_kps.numpy()

# 将处理后的关键点和匹配结果写入到文件中
with h5py.File(f"{feature_dir}/keypoints.h5", mode='w') as f_kp:
    for k, kpts1 in unique_kpts.items():
        f_kp[k] = kpts1

out_match = defaultdict(dict)
for k1, group in match_indexes.items():
    for k2, m in group.items():
        # 处理匹配结果
        m2 = deepcopy(m)
        m2[:,0] = unique_match_idxs[k1][m2[:,0]]
        m2[:,1] = unique_match_idxs[k2][m2[:,1]]
        mkpts = np.concatenate([unique_kpts[k1][m2[:,0]], unique_kpts[k2][m2[:,1]]], axis=1)
        unique_idxs_current = get_unique_idxs(torch.from_numpy(mkpts), dim=0)
        m2_semiclean = m2[unique_idxs_current]
        unique_idxs_current1 = get_unique_idxs(m2_semiclean[:, 0], dim=0)
        m2_semiclean = m2_semiclean[unique_idxs_current1]
        unique_idxs_current2 = get_unique_idxs(m2_semiclean[:, 1], dim=0)
        m2_semiclean2 = m2_semiclean[unique_idxs_current2]
        out_match[k1][k2] = m2_semiclean2.numpy()

# 将处理后的匹配结果写入到文件中
with h5py.File(f"{feature_dir}/matches.h5", mode='w') as f_match:
    for k1, gr in out_match.items():
        group = f_match.require_group(k1)
        for k2, match in gr.items():
            group[k2] = match