What you need
Choose one authorised JPEG, PNG, or WebP still image up to 20 MB and 12 million decoded pixels. Animated frames are not processed.
Image Tools / Local studio
Summarize visible decoded Rec. 709 luminance at the fifth, fiftieth, and ninety-fifth percentiles and report their robust span.
Step 1 / Source
Or browse for a JPEG, PNG, or WebP image that you own or are authorised to edit.
One file · up to 20 MB · maximum 50 megapixelsStep 2 / Output
This analysis uses one documented method so repeated runs on the same decoded pixels remain comparable.
The selected image is decoded and re-encoded inside this browser tab.
After download, the preview URL, decoded bitmap, canvas, and selected source reference are cleared.
Nirmion cannot remove the finished file from your device or browser download history.
Workflow guide
Choose one authorised JPEG, PNG, or WebP still image up to 20 MB and 12 million decoded pixels. Animated frames are not processed.
Compare consistently exported variants for broad decoded tonal spread without letting a few endpoint pixels dominate the summary.
Review and download a separate percentile-dynamic-range JSON report; the original file on your device remains unchanged.
Decision guide
Visible decoded Rec. 709 luminance values are sorted; linear interpolation returns p5, median, and p95, with p95 minus p5 as a robust span.
Percentile span is not HDR capability, exposure latitude, calibrated contrast, recoverable source detail, visual quality, or proof that tones are useful. Browser-local processing avoids a Nirmion file upload, but it cannot remove copies stored elsewhere.
OpenCV histogram tutorialGood to know
Questions answered
No. Supported JPEG, PNG, and WebP decoding, pixel inspection, transformation, and export run in your current browser tab. Nirmion does not send the selected image to its API for this workflow. The result is a separate derivative or JSON report, while the original file on your device remains unchanged and should be retained for comparison.
Visible decoded Rec. 709 luminance values are sorted; linear interpolation returns p5, median, and p95, with p95 minus p5 as a robust span. Fully transparent samples are excluded from numerical reports, while visual effects preserve source alpha. The method does not infer subjects, restore missing detail, calibrate a display, or develop raw camera data. Compare edges, gradients, text, texture, and transparent areas with the original before relying on the result.
Percentile span is not HDR capability, exposure latitude, calibrated contrast, recoverable source detail, visual quality, or proof that tones are useful. The workspace accepts one supported still image up to 20 MB and caps this pixel-intensive operation at 12 million decoded pixels for predictable browser memory use. Results depend on browser decoding and encoding support. Animation, raw development, ICC calibration, layer editing, and batch processing are outside this tool's verified scope.