Colourisation Ground Truth — gradient-sky
The full-colour reference for the gradient-sky colourisation set. Every desaturated clip in this group was derived from these exact pixels with a documented luma transform, so a colouriser's output can be scored against the true colours.
Specifications
- Resolution
- 640x360
- Fps
- 24
- Saturation
- full
- Role
- ground truth
- Crf
- 14
- Base Plate
- gradient-sky
What is a .mp4 file?
MP4 (MPEG-4 Part 14) is a widely supported multimedia container based on ISOBMFF that holds video, audio, subtitles, and metadata, most commonly H.264 or H.265 video with AAC audio. It supports streaming, chapters, and multiple tracks. It is the dominant format for distributing and playing digital video.
How to use this file
Use an example MP4 to test container demuxing, track and codec detection, seeking and streaming, and transcoding or thumbnail-extraction pipelines.
How to use this file for testing
“Colourisation Ground Truth — gradient-sky” is a deterministic Novus Examples fixture for Video colourisation, Video QA. Greyscale, sepia and partially-desaturated clips shipped beside the full-colour original they were derived from, including a 24-patch chart with documented values — so a colourisation model's output can be scored per patch rather than judged by eye.
Documented properties for this file: ground truth · 24 fps. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.
Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.
Media fixtures are short and synthetic by design. Prefer waveform or transcript ground truth in the same group when measuring ASR, trim, upscale, or sync tools; do not assume broadcast-quality masters.
Code examples
<video controls preload="metadata" width="640" src="gradient-sky-colour.mp4"></video>Related files
- mp4Colourisation Ground Truth — colour-patchesThe full-colour reference for the colour-patches colourisation set. Every desaturated clip in this group was derived from these exact pixels with a documented luma transform, so a colouriser's output can be scored against the true colours — and on this plate the 24 patch values are fixed and published, so the comparison can be made per patch rather than as a whole-frame average.
- mp4Colourisation Ground Truth — pan-cityThe full-colour reference for the pan-city colourisation set. Every desaturated clip in this group was derived from these exact pixels with a documented luma transform, so a colouriser's output can be scored against the true colours.
- mp4Colourisation Input — colour-patches, 50% DesaturatedThe colour-patches plate with 50% of its saturation removed, leaving 50% of the original chroma. This is the faded-archive case rather than the black-and-white one: some colour information survives, so the task is restoration rather than invention, and a model that ignores the residual chroma is throwing away the strongest signal it has.
- mp4Colourisation Input — colour-patches, 80% DesaturatedThe colour-patches plate with 80% of its saturation removed, leaving 19% of the original chroma. This is the faded-archive case rather than the black-and-white one: some colour information survives, so the task is restoration rather than invention, and a model that ignores the residual chroma is throwing away the strongest signal it has.
- mp4Colourisation Input — colour-patches, Rec. 601 lumaThe colour-patches plate desaturated using Rec. 601 luma weights. Rec. 601 weights instead — the SD standard, and still the default in a surprising amount of software. The greys differ measurably from the 709 version, which is a good check on whether a pipeline knows which standard it is using.
- mp4Colourisation Input — colour-patches, Rec. 709 lumaThe colour-patches plate desaturated using Rec. 709 luma weights. Converted with Rec. 709 luma weights, the correct coefficients for HD material. All chroma is gone, so a colouriser has nothing to recover from and must infer it entirely.
Generated by generation/video_ai_suites.py. Free for any use, no attribution required — license.