| --- |
| license: cc-by-nc-4.0 |
| task_categories: |
| - image-segmentation |
| tags: |
| - medical |
| - ophthalmology |
| - cataract-surgery |
| - surgical-video |
| - intraocular-lens |
| - pupil |
| size_categories: |
| - n<1K |
| --- |
| |
| # LensID — lens & pupil segmentation |
|
|
| Segmentation subsets of **LensID** (Ghamsarian et al., MICCAI 2021), a cataract-surgery |
| dataset from ITEC, Alpen-Adria-Universität Klagenfurt and the Department of |
| Ophthalmology, Klinikum Klagenfurt. Frames are extracted from surgical microscope |
| video of the anterior segment of the eye. |
|
|
| | | | |
| |---|---| |
| | Modality | Cataract surgery microscope video (RGB), annotated on extracted 2D frames | |
| | Anatomy | Eye, anterior segment | |
| | Targets | `lens` (intraocular lens implant), `pupil` | |
| | Images | **401 unique** (train 292 / test 109) | |
| | `lens_mask` | 401 (every row) | |
| | `pupil_mask` | 189 (train 141 / test 48) — `null` on the other 212 | |
| | Resolutions | 1024×768 (299 frames) and 720×720 (102 frames) | |
| | Mask format | binary PNG, single channel, values `{0, 255}` | |
| | Official split | preserved as released; **no video appears in both splits** | |
|
|
| ## Important: `lens` ⊂ `pupil` — the two targets NEST |
|
|
| The intraocular lens sits inside the pupil aperture. Measured over all 189 frames |
| that carry both masks: |
|
|
| * **99.59 %** of `lens` pixels fall inside `pupil` (per-frame minimum 94.01 %) |
| * only 68.19 % of `pupil` pixels fall inside `lens` |
|
|
| They are therefore published as **two independent binary masks**. Do **not** merge |
| them into a single `{0, 1=pupil, 2=lens}` label map — that would silently reduce |
| "pupil" to a rim annulus and change what the benchmark measures. |
|
|
| ## Important: `pupil` is an annotation layer, not extra images |
|
|
| The 189 images in the upstream `Dataset_pupil.zip` are **byte-identical duplicates** |
| of 189 images in `Dataset_lens.zip` (md5 match on all 189, same split, same |
| filename). This mirror stores each image **once** and marks pupil availability with |
| `has_pupil_mask`. Unique images = 401, not 590. |
|
|
| Pupil annotations cover exactly the 189 **non-`case_`** frames; the 212 |
| `case_3xxx` frames have a lens mask only. |
| |
| ## Naming and grouping |
| |
| `group_id` is the safe key for group-wise splitting or video assembly — it is never |
| null. `video_id` is null only for the 10 `t1xxxx` frames, whose video of origin is |
| not recoverable from the release. |
| |
| | `source_group` | example | `video_id` | n | size | |
| |---|---|---|---|---| |
| | `case_XXXX` | `case_3155_000002` | `case_3155` | 212 | 1024×768 | |
| | `Vnn_nnn` | `V11_123` | `V11` | 87 | 1024×768 | |
| | `Vn_6digit` | `V1000006`, `V000139` | `V1`, `V` | 92 | 720×720 | |
| | `t1xxxx` | `t10001` | `null` | 10 | 720×720 | |
| |
| The V-series rule is *strip the trailing 6 digits*. Ten files carry no video digit |
| and share the bare prefix `V`; grouping them as one video is what makes the paper's |
| counts reconcile exactly — 21 train / 6 test videos for lens, 13 / 3 for pupil, |
| 27 videos in total. |
| |
| ## Deviations from the upstream archives |
| |
| 1. **`Dataset_phase.zip` is not mirrored.** It is 367 GB of `.avi` clips for binary |
| Implantation-vs-Rest *classification* and contains no segmentation masks. |
| 2. **One orphan mask dropped**: `lens/test/V000268_31.png` had no matching image |
| (402 masks vs 401 images) and was 512×512 RGB where its group is 720×720 L. |
| A proper `V000268` image+mask pair is present and unaffected. |
| 3. **Masks normalised to single-channel `L`.** Upstream ships a mix of RGB and L. |
| Every RGB mask was verified to have three identical channels, so this is lossless. |
| Values remain exactly `{0, 255}`. |
| 4. Images are byte-for-byte the upstream PNGs; no resizing or re-encoding. |
|
|
| ## Scope note |
|
|
| "LensID" is the name of the *framework* in the paper. The `lens` target is the |
| **artificial intraocular lens (IOL) implant after implantation** — not the natural |
| crystalline lens and not the cataract. |
|
|
| ## Overlap with other cataract datasets |
|
|
| No frame overlap with Cataract-101 (`case_269`–`case_934` vs LensID's |
| `case_3091`–`case_3262`; the ID spaces are disjoint), Cataract-21, IrisPupilSeg, |
| InSegCat or CatRelDet. CaDIS / CATARACTS-2018 were recorded at Brest University |
| Hospital, France; LensID is Klagenfurt, Austria. **Cataract-1K** shares the same two |
| anatomy targets but was recorded 2021–2023, after LensID published — target |
| duplication, not data duplication. No cross-reference ID column exists upstream. |
|
|
| ## License |
|
|
| **CC BY-NC 4.0**, as stated on the official dataset page. |
|
|
| The authors' page adds a further restriction, reproduced verbatim: |
|
|
| > This dataset is exclusively provided for scientific research purposes and as such |
| > cannot be used commercially or for any other purpose. If any other purpose is |
| > intended, you may directly contact the originators of the datasets. |
|
|
| This mirror exists for non-commercial scientific research only. Source: |
| <https://ftp.itec.aau.at/datasets/ovid/LensID/> |
|
|
| ## Citation |
|
|
| ```bibtex |
| @inproceedings{ghamsarian2021lensid, |
| title = {LensID: A CNN-RNN-Based Framework Towards Lens Irregularity |
| Detection in Cataract Surgery Videos}, |
| author = {Ghamsarian, Negin and Taschwer, Mario and |
| Putzgruber-Adamitsch, Doris and Sarny, Stephanie and |
| El-Shabrawi, Yosuf and Schoeffmann, Klaus}, |
| booktitle = {MICCAI 2021}, |
| series = {LNCS}, |
| volume = {12908}, |
| pages = {76--86}, |
| year = {2021}, |
| doi = {10.1007/978-3-030-87237-3_8} |
| } |
| ``` |
|
|
