JPEG Artefact Clean Reference (512px)
Lossless PNG ground truth for JPEG blocking / ringing artefact repair tests.
Specifications
- Width
- 512
- Height
- 512
- Role
- lossless reference
- Seed
- 950
What is a .png file?
PNG (Portable Network Graphics) is a raster image format using lossless DEFLATE compression. It supports full 8- or 16-bit-per-channel truecolor, palette, and greyscale modes with an optional alpha channel, but no animation. It is the standard choice for screenshots, logos, and graphics with sharp edges or transparency.
How to use this file
Use an example PNG to test image decoders, alpha-compositing, thumbnail generators, and format converters, or to verify that a pipeline preserves transparency and color depth on round-trip.
How to use this file for testing
“JPEG Artefact Clean Reference (512px)” is a deterministic Novus Examples fixture for Image enhancement, Compression testing, Image pipeline QA. Clean references with underexposed, overexposed, low-contrast, cast, haze, and heavy JPEG-artefact variants for auto-enhance, dehaze, and artefact-repair tools.
Documented properties for this file: 512×512 · seed 950 · lossless reference. 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.
For image AI or enhancement tools, run the model or filter on this file and diff against the clean or ground-truth companion in the same group when available. Keep seeds and documented damage parameters in your evaluation notes so regressions are attributable.
Run your enhancement model on the degraded input and diff against the clean ground-truth companion in the same group; keep the documented degradation parameters and seed in your eval notes so scores are reproducible.
Code examples
<img src="fruit-clean.png" alt="Example image" width="640" loading="lazy">Related files
- jpgBaseline JPEGThe fruit still life as a baseline (sequential) JPEG — paired with a progressive JPEG of identical content for testing decode order and progressive-rendering support.
- pngEnhancement Clean Reference — Fruit (512px)Clean fruit still life for a second enhancement ladder subject.
- pngEnhancement Clean Reference — Mug (512px)Correctly exposed mug reference for scoring auto-enhance, exposure correction, and dehaze tools.
- pngEnhancement Input — Cool Cast Mug (512px)Mug photo with deliberate cool cast for testing auto-enhance and colour/exposure correction against the clean reference.
- pngEnhancement Input — Haze Mug (512px)Mug photo with deliberate haze for testing auto-enhance and colour/exposure correction against the clean reference.
- pngEnhancement Input — Hazy Fruit (512px)Hazy fruit scene for dehaze / clarity enhancement tests.
Generated by generation/images_enhance_wave_a.py. Free for any use, no attribution required — license.