How to threshold an image when background and foreground color are similar to each other?

Question

Oguzhan Guvercin 2021-12-1

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1600459-how-to-threshold-an-image-when-background-and-foreground-color-are-similar-to-each-other

评论： Oguzhan Guvercin 2021-12-3

Hi i would like to mask the background in this image so i have only the face of this baby as the output. But the background colors are very similar to the face skin color so when I'm applying thresholding im also losing the portion of the face or including the region that are unnecesary. How can I tackle this issue? What pre processing techniques should use? Or should take a different approach to the problem? What would you suggest?

Thanks in advance.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

yanqi liu 2021-12-2

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1600459-how-to-threshold-an-image-when-background-and-foreground-color-are-similar-to-each-other#answer_845590

clc; clear all; close all;

img = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/819834/image.png');

% method 1

jmg = rgb2ycbcr(img);

s = jmg(:,:,2);

bw = ~imbinarize(s);

bw = bwareafilt(imopen(bw, strel('disk', round(size(bw,2)/5))), 1);

stats = regionprops(bw);

figure;

subplot(2, 2, 1); imshow(img);

subplot(2, 2, 2); imshow(s, []);

subplot(2, 2, 3); imshow(bw, []);

subplot(2, 2, 4); imshow(img, []);

hold on; rectangle('position', stats(1).BoundingBox, 'EdgeColor', 'g', 'LineWidth', 2)

% method 2

faceDetector = vision.CascadeObjectDetector();

faceDetector.ScaleFactor = 1.01;

bbox = step(faceDetector, img);

figure;

imshow(img);

hold on; rectangle('position', bbox(1,:), 'EdgeColor', 'g', 'LineWidth', 2)

3 个评论
显示 1更早的评论隐藏 1更早的评论

yanqi liu 2021-12-2

yes，sir

The main idea is to transform the color space and extract the skin color region. The face has obvious continuous skin color characteristics, and there are face edges around. Therefore, although the background is partially repeated, the face is still a relatively large region. Through morphological filtering, the interference of the background can be eliminated and the face candidate region can be obtained. Of course, other color space analysis can also be considered.

Oguzhan Guvercin 2021-12-3