Update readme for links addition

README.md

@@ -14,9 +14,9 @@ tags:
 
 DSR Benchmark is a dataset for studying the quality of images produced by
 classic and diffusion-based Super-Resolution (SR) methods. The public release
-contains all selected SR images, along with the references and subjective
-quality scores for 60% of the SR images in each category. The data associated
-with the remaining 40% are reserved for a future challenge.
+contains all selected SR images, along with the LR inputs, HR source links, and
+subjective quality scores for 60% of the SR images in each category. The data
+associated with the remaining 40% are reserved for a future challenge.
 
 ## Dataset summary
 
@@ -60,6 +60,10 @@ Example:
 00014_vg_dsr.jpg
 ```
 
+The HR image files are not redistributed in the public repository. For the
+public partition, links to the original HR images or their source pages are
+provided in `metadata/hr_source_links.csv`.
+
 ## LR generation
 
 Each HR image was downscaled using bicubic interpolation at two scale factors:
@@ -166,8 +170,8 @@ obtained by aggregating its individual ratings.
 
 Public annotations cover 60% of the Diffusion SR images and 60% of the Classic
 SR images. For the remaining 40%, the SR images themselves are available, but
-their corresponding MOS values, individual votes, LR images, and HR images are
-not published.
+their corresponding MOS values, individual votes, LR images, and HR source
+links are not published.
 
 > **Note on score representation.** The CSV files contain numeric values in
 > the form in which they were exported and used to calculate MOS. The data
@@ -185,9 +189,6 @@ with source ID `00014` are stored in shard `000`. The shard name is denoted by
 .
 ├── README.md
 ├── images/
-│   ├── hr/
-│   │   └── {prefix}/
-│   │       └── xxxxx_vg_dsr.jpg
 │   ├── lr/
 │   │   ├── x2/
 │   │   │   └── {prefix}/
@@ -206,17 +207,29 @@ with source ID `00014` are stored in shard `000`. The shard name is denoted by
     ├── mos.csv
     ├── votes.csv
     ├── mos_csr.csv
-    └── votes_csr.csv
+    ├── votes_csr.csv
+    └── hr_source_links.csv
 ```
 
 The public repository intentionally does not include `split_assignment.csv` or
-`sr_manifest.csv`. Available SR, LR, and HR images can be matched using the
-five-digit `xxxxx` identifier in their filenames.
+`sr_manifest.csv`. Available SR and LR images, as well as the corresponding HR
+source links, can be matched using the five-digit `xxxxx` identifier.
+
+### `metadata/hr_source_links.csv`
+
+Contains source information and links for the HR references associated with
+the public partition. The HR files themselves are not redistributed in this
+repository. Match a row to an LR or SR image using `source_id` or
+`hr_file_name`, then use `source_url` to access the original image or its
+source page.
 
-### `images/hr/{prefix}/`
+The `source_url_type` column indicates the type of destination:
 
-Contains HR references for the public partition only. HR images corresponding
-to the hidden 40% of SR images are not included.
+- `exact_image` — a direct link to the original image;
+- `exact_image_page` — a page containing the original image;
+- `dataset_page_only` — the source dataset page, when an image-specific link
+  is unavailable;
+- `unresolved` — no suitable public link was resolved.
 
 ### `images/lr/x2/{prefix}/` and `images/lr/x4/{prefix}/`
 
@@ -286,16 +299,19 @@ the SR image
 CODSR_x2_00014_vg_dsr_blur_x2.jpg
 ```
 
-has the following references when they are publicly available:
+has the following public LR reference:
 
 ```text
 images/lr/x2/000/00014_vg_dsr_blur_x2.jpg
-images/hr/000/00014_vg_dsr.jpg
 ```
 
-If the corresponding LR and HR files are absent from the public repository,
-the SR image belongs to the challenge partition, and its MOS and votes are not
-published either.
+The corresponding HR filename is `00014_vg_dsr.jpg`. Its source link can be
+obtained from the row with `source_id=00014` in
+`metadata/hr_source_links.csv`.
+
+If the corresponding LR file and HR-link row are absent from the public
+repository, the SR image belongs to the challenge partition, and its MOS and
+votes are not published either.
 
 ## Loading the annotations
 
@@ -314,18 +330,25 @@ classic_mos = pd.read_csv(
     root / "metadata/mos_csr.csv",
     index_col=0,
 )
+hr_links = pd.read_csv(
+    root / "metadata/hr_source_links.csv",
+    dtype={"source_id": str},
+)
 
 print(diffusion_mos.head())
 print(classic_mos.head())
+print(hr_links.head())
 ```
 
-The path of an image can be reconstructed from its source identifier:
+The LR and SR paths and the HR source URL can be obtained from the source
+identifier:
 
 ```python
 source_id = "00014"
 prefix = source_id[:3]
 
-hr_path = root / "images/hr" / prefix / f"{source_id}_vg_dsr.jpg"
+hr_row = hr_links.loc[hr_links["source_id"] == source_id].iloc[0]
+hr_url = hr_row["source_url"]
 lr_path = root / "images/lr/x2" / prefix / f"{source_id}_vg_dsr_blur_x2.jpg"
 sr_path = (
     root
@@ -366,8 +389,8 @@ print(source_id)  # 00014
   of KonIQ-10k, COCO, AVA, and FLIVE.
 - The public and challenge partitions are grouped by HR content; therefore,
   exactly 60% of the HR groups need not be public.
-- Missing LR, HR, or MOS data in the public release are part of the challenge
-  protocol and do not indicate dataset corruption.
+- Missing LR, HR source-link, or MOS data in the public release are part of the
+  challenge protocol and do not indicate dataset corruption.
 
 ## Terms of use and attribution