How to run prep_refdrone_data.py
This script prepares the RefDrone test split for public inference. It is strictly web-only: every annotation and image is downloaded from a public mirror on each run. The script never reads any pre-existing local copy of RefDrone or VisDrone elsewhere on disk.
Prerequisites
- Python 3.8 or later
- Internet access (for HuggingFace and the VisDrone image mirrors)
- About 1 GB of free disk for the temporary archive plus the extracted images
Web sources
| What | Source | Size |
|---|---|---|
Annotation JSON (RefDrone_test_mdetr.json) |
https://huggingface.co/datasets/sunzc-sunny/RefDrone/resolve/main/RefDrone_test_mdetr.json |
~3.3 MB |
Image archive (VisDrone2019-DET-test-dev.zip) — primary |
https://github.com/ultralytics/assets/releases/download/v0.0.0/VisDrone2019-DET-test-dev.zip (Ultralytics GitHub Release) |
~297 MB |
| Image archive — fallback | Google Drive id 1PFdW_VFSCfZ_sTSZAGjQdifF_Xd5mf0V via gdown (canonical link from https://github.com/VisDrone/VisDrone-Dataset) |
~297 MB |
The image archive is tried in the order listed. The script falls through to the next mirror automatically if one fails (including the well-known Google Drive "too many users" quota error).
Step 1 — Navigate to the repo root
cd /path/to/iib
The script's repo root is the iib/ directory. All commands below are run from
there.
Step 2 — Install gdown (only required for the Google Drive fallback)
pip install gdown
If the primary HTTPS mirror works, gdown is not invoked. Installing it
up-front is still recommended so the fallback works on machines where the
primary mirror is unreachable.
Step 3 — Run the script
python3 scripts/refdrone/prep_refdrone_data.py
Flags:
| Flag | Effect |
|---|---|
--force |
Re-download annotation and image archive even if outputs exist |
--keep-zip |
Keep the downloaded VisDrone2019-DET-test-dev.zip after extraction (default: deleted) |
What the script does
- Downloads
RefDrone_test_mdetr.jsonfrom HuggingFace (~3.3 MB). - Parses the annotation and writes
refdrone_data.jsonl(3,276 rows, one per referring expression — no GT bboxes are ever written to this file). - Downloads
VisDrone2019-DET-test-dev.zip(~297 MB) from the first working mirror, validates size, validates SHA-256, extracts the 1,503 required images intoimages/, then deletes the zip (unless--keep-zip). - Writes a
data_summary.jsonreport underreports/recording which mirror was used. - Hard-validates final counts: exactly 3,276 JSONL rows and exactly
1,503
.jpgfiles. Any mismatch aborts with a non-zero exit code.
Output structure
Outputs are written under the repo root at:
iib/LMUData/Spatial/2d_referring_expressions/refdrone/
├── refdrone_data.jsonl # 3,276 rows
├── annotations_raw/
│ └── RefDrone_test_mdetr.json # ~3.3 MB
├── images/ # 1,503 .jpg files
└── reports/
└── data_summary.json
Step 4 — Verify success
ROOT=iib/LMUData/Spatial/2d_referring_expressions/refdrone
# Annotation row count — must be 3276
wc -l "$ROOT/refdrone_data.jsonl"
# Image count — must be 1503
find "$ROOT/images" -name '*.jpg' | wc -l
# Confirm files_missing is 0 in the summary report
python3 -c "import json; print(json.load(open('$ROOT/reports/data_summary.json'))['images']['files_missing'])"
A run is successful only when:
refdrone_data.jsonlhas exactly 3,276 lines, andimages/contains exactly 1,503.jpgfiles, and- The script ended with
Preparation complete (web-only download verified).
The script enforces these checks itself in step 5 of its own flow and exits non-zero on any deviation.
Re-running
python3 scripts/refdrone/prep_refdrone_data.py # normal run; reuses prior outputs from this script
python3 scripts/refdrone/prep_refdrone_data.py --force # ignore prior outputs, re-download from scratch
python3 scripts/refdrone/prep_refdrone_data.py --keep-zip # keep the 297 MB zip after extraction
A re-run after a partial failure is safe: if a previous run already extracted
all 1,503 images into images/, the script logs that fact explicitly and
skips re-downloading. This is the only on-disk reuse the script performs;
external local copies of VisDrone or RefDrone elsewhere on the machine are
never consulted.
Troubleshooting
Primary HTTPS mirror unreachable
[images] Mirror FAILED: ultralytics-github-release — <error>
[images] Trying mirror: google-drive-original (gdrive)
The script automatically advances to the Google Drive fallback. No action needed unless both mirrors fail.
Google Drive quota error
[images] Mirror FAILED: google-drive-original — Google Drive refused the
request (likely quota / 'too many users' throttling): ...
If this is the only failure (primary mirror succeeded), the run already
finished correctly. If both mirrors failed, the script aborts with ERROR: All image-zip mirrors failed. Wait an hour and retry, or download the zip in a
browser from
https://github.com/ultralytics/assets/releases/download/v0.0.0/VisDrone2019-DET-test-dev.zip
and re-run; the script will resume.
Behind a firewall that blocks GitHub release assets
Allowlist release-assets.githubusercontent.com (Microsoft Azure Blob backend
for GitHub Releases). With that domain blocked, the primary mirror cannot
download even the redirected URL.
gdown not installed
ERROR: gdown is required ... Install it with: pip install gdown
Run pip install gdown. The fallback Google Drive mirror needs it; the
primary HTTPS mirror does not.
Checksum mismatch on the downloaded zip
ERROR: Checksum mismatch for VisDrone2019-DET-test-dev.zip
The file has been deleted. Re-run the script to download again.
The download was truncated or the upstream file changed. The corrupt zip is already removed; just re-run the script. The script tries each mirror's own SHA-256, so a successful download from any mirror is byte-verified.
Final-validation failure
[validate] FAILED:
- <one or more issues>
ERROR: Output validation failed.
The dataset is incomplete or corrupted. Run with --force to redo the
downloads from scratch.