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
Measure mean absolute decoded RGBA differences between pixel pairs mirrored across the vertical and horizontal canvas axes.
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 synthetic icons or patterns intended to be symmetric while inspecting alignment, anti-aliasing, and transparent padding at full size.
Review and download a separate bilateral-symmetry JSON report; the original file on your device remains unchanged.
Decision guide
Opposite pixels are paired across each geometric axis; absolute red, green, blue, and alpha differences are averaged over all compared pairs.
Pixel symmetry is not subject pose, semantic symmetry, aesthetic balance, registration accuracy, perceptual similarity, or design approval. Browser-local processing avoids a Nirmion file upload, but it cannot remove copies stored elsewhere.
MDN Canvas pixel manipulationGood 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.
Opposite pixels are paired across each geometric axis; absolute red, green, blue, and alpha differences are averaged over all compared pairs. Every decoded RGBA tuple participates, including fully transparent pixels whose stored channel bytes may differ. 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.
Pixel symmetry is not subject pose, semantic symmetry, aesthetic balance, registration accuracy, perceptual similarity, or design approval. 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.