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Image Tools / Local studio

Image Alpha Mask Exporter

Copy every decoded alpha byte into grayscale RGB, force opaque output pixels, and export a visible lossless transparency mask.

Runs locallyNo image upload to Nirmion

Step 1 / Source

Choose one image

JPEG · PNG · WebP · 20 MB

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 megapixels

Step 2 / Output

Image Alpha Mask Exporter method

This workflow uses one fixed, documented method so repeated runs on the same decoded pixels are comparable. Processing stays in this browser tab.

Create the opaque grayscale alpha-mask PNGThe source is not overwritten. Export creates a separate opaque grayscale alpha-mask 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 alpha mask exporter with an inspectable review path

Each source alpha byte is copied to red, green, and blue while output alpha is set to fully opaque so transparency remains visible as luminance. Compare the result with the untouched source before using it downstream.
A

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.

B

Social-ready choices

Inspect soft cutout edges and unintended transparent holes before compositing an authorised PNG over a new background.

C

What you receive

Download a separate opaque grayscale alpha-mask PNG; the original file on your device remains unchanged.

Decision guide

What image alpha mask exporter measures or changes

Each source alpha byte is copied to red, green, and blue while output alpha is set to fully opaque so transparency remains visible as luminance.

The mask visualizes decoded alpha only; it does not segment subjects, create missing transparency, refine hair, or preserve source RGB colour. Browser-local processing avoids a Nirmion file upload, but it cannot remove copies stored elsewhere.

W3C Compositing and Blending Level 1

Useful checks for image alpha mask exporter

  1. Inspect soft cutout edges and unintended transparent holes before compositing an authorised PNG over a new background.
  2. Create a bounded review derivative while retaining the original for comparison, correction, or a different method.
  3. 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 Alpha Mask Exporter upload my image?

No. For supported JPEG, PNG, and WebP inputs, 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 report, while the original file on your device remains unchanged and should be retained for comparison.

How does Image Alpha Mask Exporter work?

Each source alpha byte is copied to red, green, and blue while output alpha is set to fully opaque so transparency remains visible as luminance. Source alpha becomes grayscale output luminance and each exported pixel is opaque so the mask can be inspected directly. The method does not infer subjects, restore missing detail, calibrate a display, or develop raw camera data. Compare fine edges, gradients, text, texture, and transparent pixels with the original before relying on the result.

What are the limits of Image Alpha Mask Exporter?

The mask visualizes decoded alpha only; it does not segment subjects, create missing transparency, refine hair, or preserve source RGB colour. 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.