MATLAB: How can i somehow autofill black-spots in an RGB image.

autocorrectautofillimage processingImage Processing Toolbox

Threshold for black.

mask = grayImage == 0;

Extract the two largest regions

mask = bwareafilt(mask, 2);

Then find the centroid or bounding box

props = regionprops(mask, 'Centroid');

and extract the lower black region. See if you can do this yourself.

Call imerode() to shrink it. Then XOR the shrunken region with the original region to get just the edges.

mask = imerode(lowerMask, true(9)); % Increase from 9 to get a wider white region.
mask = xor(mask, lowerMask);

Then set those pixels in the original image to white:

grayImage(mask) = 255;

There are many ways do remove background. If you have a colored image, then you can try this

If you have a gray scale image, then you can try this

Hope it helps you.

Meshoo