How to fill an object with the same color as surrounding pixels?

Hello,

I have following image.

And I would like to fill the white whole, with the same color as the gray circle outside, so that would like as the following image:

Here what I have done just know:

close all; clear all;

Im1=imread('Im1.bmp');
Im2 = rgb2gray(Im1);
figure; imshow(Im1);
bw=im2bw(Im1,0.9);
bw_dilated = imdilate(bw,strel('disk',3));

%[I,J,V] = find(Im2, B{1,1}(1:end,1));

avgPrecisionSize = 16; % smaller is better, but takes longer
G = fspecial('gaussian',[1 1]*100,50);
H = fspecial('average', [1,1]*avgPrecisionSize);

%# User a big filter to get started:
newImage = imfilter(Im2,G,'same');
newImage(~bw_dilated) = Im1(~bw_dilated);

numIterations = 30;
for count = 1:numIterations
   newImage = imfilter(newImage, H, 'same');
   newImage(~bw_dilated) = Im1(~bw_dilated);
end

%%Plot the results
figure(123);
clf;

% Display the mask:
subplot(1,2,1);
imagesc(Im1);
axis image
title('Region Of the Bad Pixels');

% Display the result:
subplot(1,2,2);
imagesc(newImage);
axis image
set(gca,'clim', [0 255])
title('Infilled Image');

colormap gray

And here is what I got:

[MATLAB] version 2015b

Answer 1

[Jeff E]

If you're always dealing with pixels regions that have the same values, then the below should work:

Im1=imread('Im1.bmp');
Im2 = rgb2gray(Im1);

gray_value = 195 ; %empirically derived value of gray pixels in ring

white_mask = Im2 > 250 ; %empirically derived threshold to make binary mask of white pixels

Im2(white_mask) = gray_value ; %assign all pixels in white_mask the intensity (gray_value)

imshow(Im2);

If the values of the pixels changes, this problem becomes more complex.

[Image Analyst]

And if the outer region is not a uniform intensity, then you can use regionfill(), which basically smears the surrounding pixels in towards the middle of the region (a weighted interpolation).