Hi can any one please tell me how to remove some pixels from the image which defined D4 below. basically I want to remove all pixels from D4 which lying below a threshold ?

A=imread('image.png'); g=A(:, :, 2); % subplot(3,3,1); % imshow(g); % title('green'); g2=adapthisteq(g); subplot(3,3,1); imshow(g2); title('equal1') g3=adapthisteq(g2); subplot(3,3,2); imshow(g3); title('equal2') I=rgb2gray(A); J = imadjust(I,[],[],0.25); subplot(3,3,3); imshow(J); title('brighten') bw1 = edge(g2,'canny',0.1); subplot(3,3,4); imshow(bw1); title ('canny1') bw2 = edge(J,'canny',0.1); subplot(3,3,5); imshow(bw2); title ('canny2') se=strel('disk',1,0); erode=imerode(bw2,se); % subplot(3,3,7); % imshow(erode); % title('erode') dilate=imdilate(bw2,se); d1=dilate-erode; subplot(3,3,6); imshow(d1); title('difference') d2=bw1-d1; subplot(3,3,7); imshow(d2); title('d2'); d3=imfill(d2,'holes'); subplot(3,3,8); imshow(d3); title('d3'); d4= im2bw(d3,0.5) - im2bw(d2,0.5); subplot(3,3,9); imshow(d4); title('d4');