How AI Finds the Subject
Cutting a subject out of a photo used to mean tracing edges by hand. AI segmentation replaces that with a model that has seen millions of photos and learned what subjects look like: people, products, animals, furniture, plants. For every pixel in your photo, the network estimates how strongly it belongs to the subject versus the background.
The result of that estimation is called an alpha matte, a transparency map at the same resolution as the analysis. Solid subject areas become fully opaque, background becomes fully transparent, and boundary pixels get values in between. Those in-between values are what make hair, fur, and soft edges look natural instead of cut out with scissors.
This tool runs ISNet, a segmentation architecture from the dichotomous image segmentation family that also underlies several commercial services. The matte is computed at 1,024 by 1,024 and then scaled back onto your original photo, so the download keeps your full resolution with transparency applied.