extract pixels where value is greater or less than a specified value

Hi how can i extract the list of pixels from imgf that are less than 93?

i have to only check the pixels that are in the ind variable.....

img = imread('images\vertebre.png');
imgf = medfilt2(img, [7 7]);
binf = 93;
bsup = 117;
ind = ([154718;155227;155228;155229;155736;155737;155739;155740;156247;156248;156249;156758]);
inf_seg = 93 < imgf; %%%%how do i make this line only check pixels that are in the ind variable....

Answer 1

[Image Analyst]

Use ismember() to determine if one set of values is contained within another set of values.

Not sure what ind represents. Linear indexes?

[ia, ib] = ismember(ind, find(inf_seg));

[Julien Roussel]

actually here's my full code....

my main issue is that in these 2 lines Im affecting every pixels not only the ones i extracted in the variable ind

 inf_seg = binf < imgf;
 sup_seg = imgf < bsup;

img = imread('images\vertebre.png');
imshow(img);

[x, y] = ginput(1);
x = uint16(x);
y = uint16(y);

imgf = medfilt2(img, [7 7]);
imshow(imgf);
elemd2 = strel('disk', 2, 0);
seg = false(510, 628);
seg(y, x) = true;
seg_precedent = false(510, 628);
dispMat = zeros(size(img));

while (~isequal(seg, seg_precedent))
    seg_precedent = seg;
    intensite_region = double(imgf(seg));
    m_region = mean(intensite_region);
    std_region = std(intensite_region);
    seg_dilate = imdilate(seg, elemd2);
    contour = seg_dilate - seg;
    ind = find(contour==1);
    delta = 12;
    binf = m_region - (std_region + delta);
    bsup = m_region + (std_region + delta);
    inf_seg = binf < imgf;
    sup_seg = imgf < bsup;
    candidats = inf_seg  & sup_seg ;
    seg = candidats;
    dispMat = img;
    dispMat(seg) = 0;
    RGB = cat(3,uint8(seg)*255+dispMat,dispMat,dispMat);
    imshow(RGB, [])
    drawnow
end