Image Processing - Dress Segmentation using opencv

Question

I am working on dress feature identification using opencv. As a first step, I need to segment t-shirt by removing face and hands from the image. Any suggestion is appreciated.

Answer 1

I suggest the following approach:

1. Use Adrian Rosebrock's skin detection algorithm for detecting the skin (thank you for Rosa Gronchi for his comment).
2. Use region growing algorithm on the variance map. The initial seed can be calculated by using stage 1(see the attached code for more information).

code:

%stage 1: skin detection -  Adrian Rosebrock solution
im = imread(<path to input image>);
hsb = rgb2hsv(im)*255;

skinMask = hsb(:,:,1) > 0 & hsb(:,:,1) < 20;
skinMask = skinMask & (hsb(:,:,2) > 48 & hsb(:,:,2) < 255);
skinMask = skinMask & (hsb(:,:,3) > 80 & hsb(:,:,3) < 255);
skinMask = imclose(skinMask,strel('disk',6));

%stage 2: calculate top, left and right centroid from the different connected
%components of the skin
stats = regionprops(skinMask,'centroid');
topCentroid = stats(1).Centroid;
rightCentroid = stats(1).Centroid;
leftCentroid = stats(1).Centroid;
for x = 1 : length(stats)
    centroid = stats(x).Centroid;
    if topCentroid(2)>centroid(2)
        topCentroid = centroid;
    elseif centroid(1)<leftCentroid(1)
        leftCentroid = centroid;
    elseif centroid(1)>rightCentroid(1)
        rightCentroid = centroid;
    end
end

%first seed - the average of the most left and right centroids.
centralSeed = int16((rightCentroid+leftCentroid)/2);

%second seed - a pixel which is right below the face centroid.
faceSeed = int16(topCentroid);
faceSeed(2) = faceSeed(2)+40; 

%stage 3: std filter
varIm = stdfilt(rgb2gray(im));

%stage 4 - region growing on varIm  using faceSeed and centralSeed
res1=regiongrowing(varIm,centralSeed(2),centralSeed(1),8);
res2=regiongrowing(varIm,faceSeed(2),faceSeed(1),8);
res = res1|res2;

%noise reduction
res = imclose(res,strel('disk',3));
res = imopen(res,strel('disk',2));

result after stage 1(skin detection):

final result:

Comments:

1. Stage 1 is calculated using the following algorithm.
2. The region growing function can be downloaded here.
3. The solution is not perfect. For example, it may fail if the texture of the shirt is similar to the texture of the background. But I think that it can be a good start.
4. Another improvement which can be done is to use a better region growing algorithm, which doesn't grows into the skinMask location. Also, instead of using the region growing algorithm twice independently, the result of the second call of region growing can can be based on the result from the first one.