Document Unsplash media retrieval TODO

README.md

@@ -299,11 +299,18 @@ mappings, and metadataset configuration, but not their image files.
 | `partimagenet` | [ImageNet](https://www.image-net.org/download.php) | `train/<wnid>/<wnid>_<id>.JPEG` |
 | `object365` | [Objects365](https://www.objects365.org/download.html) | `images/train/patch*/objects365_v1_<id>.jpg` |
 | `sku110k` | [SKU-110K](https://github.com/eg4000/SKU110K_CVPR19) | `images/train_<id>.jpg` |
-| `unsplash` | [Unsplash Dataset](https://unsplash.com/data) | `raw_unsplash_images/<photo-id>.jpg` |
+| `unsplash` | **TODO — reproducible media retrieval is not yet available** | `raw_unsplash_images/<photo-id>.jpg` |
+
+**Unsplash TODO.** The annotations and source-image mappings are included, but
+the current Unsplash distribution does not provide a stable procedure for
+reconstructing the exact historical image bytes referenced by this release.
+Unsplash media hydration is therefore not currently supported. We will document
+a reproducible retrieval and verification procedure when one is available.
 
 `metadataset.yaml` reads the datasets whose images are already hosted in this
-repository. Use `metadataset-full.yaml` only after all media listed above has
-been prepared locally.
+repository. Use `metadataset-full.yaml` only after all referenced external media
+pools are available locally. Unsplash is excluded from the currently supported
+reproducible hydration workflow.
 
 ### Prepare an upstream media dataset
 

README_CN.md

@@ -287,10 +287,15 @@ source-image mapping 和 metadataset 配置，但不包含图片文件。
 | `partimagenet` | [ImageNet](https://www.image-net.org/download.php) | `train/<wnid>/<wnid>_<id>.JPEG` |
 | `object365` | [Objects365](https://www.objects365.org/download.html) | `images/train/patch*/objects365_v1_<id>.jpg` |
 | `sku110k` | [SKU-110K](https://github.com/eg4000/SKU110K_CVPR19) | `images/train_<id>.jpg` |
-| `unsplash` | [Unsplash Dataset](https://unsplash.com/data) | `raw_unsplash_images/<photo-id>.jpg` |
+| `unsplash` | **TODO——尚无可复现的媒体获取流程** | `raw_unsplash_images/<photo-id>.jpg` |
 
-`metadataset.yaml` 读取图片已经包含在本仓库中的数据集。只有在本地补齐上述
-全部媒体后，才使用 `metadataset-full.yaml`。
+**Unsplash TODO。** 本仓库已经包含 Unsplash 标注和 source-image mapping，
+但 Unsplash 当前的发布方式无法稳定重建本版本引用的历史图片字节，因此暂不支持
+Unsplash 媒体恢复。待具备可复现的获取与校验方案后，我们会补充相应流程。
+
+`metadataset.yaml` 读取图片已经包含在本仓库中的数据集。只有在本地补齐配置
+引用的外部媒体池后，才使用 `metadataset-full.yaml`。当前支持的可复现媒体恢复
+流程不包含 Unsplash。
 
 ### 准备一个上游媒体数据集