16-bit Grayscale PNG (deep colour)
A 16-bit (deep-colour) grayscale PNG holding a smooth 0–65535 gradient, for testing high-bit-depth support and spotting banding when a tool truncates to 8-bit.
Specifications
- Width
- 512
- Height
- 512
- Bit Depth
- 16
- Mode
- I;16 (grayscale)
- Values
- 0–65535
- Alt Text
- A 16-bit (deep-colour) grayscale PNG holding a smooth 0–65535 gradient, for testing high-bit-depth support and spotting banding when a tool truncates to 8-bit
- Alt Text Source
- description
Testing contract
Expected to pass- Scenario
- Exercise 16-bit Grayscale PNG (deep colour) in its color and metadata workflow. A 16-bit (deep-colour) grayscale PNG holding a smooth 0–65535 gradient, for testing high-bit-depth support and spotting banding when a tool truncates to 8-bit.
- Expected result
- Decoded geometry is 512×512 pixels in I;16 mode; frame count is 1. Declared feature checks: bitDepth=16; mode=I;16 (grayscale); values=0–65535.
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
“16-bit Grayscale PNG (deep colour)” is a deterministic Testaroo fixture for Image pipeline QA, Conversion testing. Deterministic images with known properties for regression-testing resize, crop, convert, and filter pipelines.
Documented properties for this file: 512×512 · 16-bit. 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.
Code examples
<img src="deep-16bit-gradient.png" alt="Example image" width="640" loading="lazy">Generated by generation/images_pipeline.py. Free for any use, no attribution required, license.
Related files
- tiffLinear 16-bit Grey TIFF (deflate)64×64 linear 16-bit greyscale TIFF with deflate: Wave H depth for high bit-depth loaders.
- tiffLinear 16-bit Greyscale TIFFA linear 16-bit greyscale TIFF ramp (0–65535). Not a PQ HDR master, for testing high bit-depth TIFF loaders and 16→8 truncation.
- 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.
- jpgCMYK JPEG (print colour space)The fruit still life converted to the CMYK (print) colour space and saved as a JPEG, for testing CMYK decoding and CMYK→RGB conversion. Some web viewers render CMYK JPEGs with a colour shift.
- jpgICC sRGB-Tagged JPEGThe fruit still life saved as a JPEG with an embedded sRGB ICC colour profile, paired with an untagged copy for testing colour-management and profile handling.
- pngPNG with Metadata StrippedThe pixel-identical PNG control with text and ICC chunks removed, for proving that a scrubber changes metadata without changing decoded RGB values.
