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
Image Scanline Effect
Darken every second decoded pixel row by a bounded amount to create a repeatable horizontal display-line treatment.
Runs locallyNo image upload to Nirmion
Step 1 / Source
Choose one image
Drop your image here
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
Image Scanline Effect settings
Choose 0 to 100 percent attenuation for alternate rows; zero leaves their RGB unchanged and 100 makes them black.
Create the horizontal scanline PNGThe source is not overwritten. Export creates a separate horizontal scanline PNG.
Keep this page open until the download begins.01No server upload
The selected image is decoded and re-encoded inside this browser tab.
02Working copy released
After download, the preview URL, decoded bitmap, canvas, and selected source reference are cleared.
03Your download remains
Nirmion cannot remove the finished file from your device or browser download history.
Workflow guide
Use image scanline effect with an inspectable review path
Every second decoded row has RGB multiplied by the selected attenuation while the intervening rows and all alpha bytes remain unchanged. Compare the result with the untouched source before using it downstream.Social-ready choices
Create a retro display treatment for a copied game screenshot while checking small text and thin horizontal details.
What you receive
Download a separate horizontal scanline PNG; the original file on your device remains unchanged.
Decision guide
What image scanline effect measures or changes
Every second decoded row has RGB multiplied by the selected attenuation while the intervening rows and all alpha bytes remain unchanged.
The periodic overlay does not model a particular CRT, phosphor layout, interlacing system, display gamma, or viewing distance. Browser-local processing avoids a Nirmion file upload, but it cannot remove copies stored elsewhere.
MDN Canvas pixel manipulationUseful checks for image scanline effect
- Create a retro display treatment for a copied game screenshot while checking small text and thin horizontal details.
- Create a bounded review result while retaining the original for comparison, correction, or a different method.
- Test representative flat areas, gradients, edges, text, transparency, and high-frequency texture before accepting the output.
Good to know
Important image boundaries
- Why might a PNG not become smaller?
- PNG is lossless and browsers do not expose a quality control for it. Choose WebP or JPEG when reducing file size matters more than exact lossless pixels.
- Are animated images supported?
- No. The workspace accepts still JPEG, PNG, and WebP files. Re-encoding an animated source would otherwise keep only one frame.
- What does clearing the file mean?
- Because processing is local, there is no Nirmion server copy to delete. The tab releases its working references after success; your downloaded output remains on your device.
Questions answered
Frequently asked questions
Does Image Scanline Effect upload my image?
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.
How does Image Scanline Effect work?
Every second decoded row has RGB multiplied by the selected attenuation while the intervening rows and all alpha bytes remain unchanged. 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.
What are the limits of Image Scanline Effect?
The periodic overlay does not model a particular CRT, phosphor layout, interlacing system, display gamma, or viewing distance. 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.