How To Use The Mask AI Trimap
Mask AI uses a three color map, called the trimap, to tell the application what parts of an image to keep, what parts of an image to remove, and how to automatically determine the edges of your mask.
Applying Trimask Colors To Your Image
You will use the brush and fill buttons to apply red, blue and green colors to your image. Brushes can be adjusted to different sizes and the fill buttons will fill in large areas of the image with the selected color.
The Trimap Colors
Red - Red indicates areas you want to cut out of your image, and your image will automatically be filled in as red when you import it. As you complete your trimask, make sure that no red remains on any part of the image you want to keep.
Blue - Areas you want to compute automatically should be painted blue. The brush tool is your friend here, and you can be generous with your blue area around your edges. You want to make sure every edge you want the app to calculate automatically is within the blue "calculate" zone. Once you paint your blue zone, you can paint your cut and keep colors (red and green) closer to your mask edges if needed.
Green - You'll use the brush or fill bucket to paint the remaining areas you want to keep green, and you don't have to paint right to the edge of your "keep" area. Again, you don't have to paint right to the edges with your green. Leave space for the blue areas on the "keep" side of your image.
The end result will be a three color "map" of the areas you want to keep, compute, and remove similar to the image above.
Once your color map is complete click "Compute Mask" and let Mask AI do the work.
Pro Tip: If a particular area does not create a clean mask, zoom in on the trouble area and use a very small brush to paint small "keep" and "cut" sections INSIDE the blue "compute" area of your trimask. This will give our AI model some extra information about what to keep or cut. You don't have to paint the entire area or paint right to the edges of everything. Small lines and dots around the problem area will do the trick.
In this example, the blue water and blue life jacket were similar enough that it helped to mark the straps of her life jacket to mask out the water between the life jacket and the strap.