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
Bin Sobel gradient directions for visible pixels whose gradient magnitude reaches a fixed documented threshold.
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.
Inspect whether a synthetic pattern emphasizes horizontal, vertical, or diagonal intensity transitions at the decoded image scale.
Review and download a separate edge-orientation JSON report; the original file on your device remains unchanged.
Decision guide
Horizontal and vertical three-by-three Sobel responses form magnitude and direction; qualifying gradients enter eight 22.5-degree bins modulo 180 degrees.
Gradient direction is perpendicular to visual edge direction and depends on scale, borders, noise, compression, threshold, and decoded resolution. Browser-local processing avoids a Nirmion file upload, but it cannot remove copies stored elsewhere.
OpenCV Sobel derivatives 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.
Horizontal and vertical three-by-three Sobel responses form magnitude and direction; qualifying gradients enter eight 22.5-degree bins modulo 180 degrees. 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.
Gradient direction is perpendicular to visual edge direction and depends on scale, borders, noise, compression, threshold, and decoded resolution. 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.