how to get the pixel value of histogram?

Hello

i wants to delete or make some pixel zero , according to the bins.

im = imread ('image');
hsv_im = rgb2hsv(im);
h = hsv_im(:,:,1)
[pixelCount, grayLevels] = hist(h(:), 360);
pixelCount(20:30)=0;

Now i want to get my 'Hue' Matrix with same pixel position and zeros between the bin values from 20 to 30.

Answer 1

[DGM]

You have the bin values. You know which bins you want. Why are you zeroing the histogram counts instead of changing the image?

% the image
im = imread('rainbow.png');
hsv_im = rgb2hsv(im);
h = hsv_im(:,:,1);

% generate the mask
nbins = 360;
[~, bincenters] = hist(h(:),nbins);
maskrange = bincenters([20 30]) + [-0.5 0.5]/nbins;
mask = (h >= maskrange(1)) & (h <= maskrange(2));

% make the masked region red
h(mask) = 0;

% reassemble the image
hsv_im(:,:,1) = h;
outpict = hsv2rgb(hsv_im);

% it's red
imshow(outpict)

Of course I have to question whether the goal was to actually set orange pixels to red, or whether it was to reshape the entire histogram such that there are no orange pixels. I guess we'll never know.

EDIT:

Just because I felt like it:

% the image
im = imread('rainbow.png');
hsv_im = rgb2hsv(im);
h = hsv_im(:,:,1);

% crudely reshape the histogram
nbins = 360;
[bincounts, bincenters] = imhist(h,nbins);
bincounts(20:30) = 0;

% make the masked region red
hnew = histeq(h,bincounts);

% reassemble the image
hsv_im(:,:,1) = hnew;
outpict = hsv2rgb(hsv_im);

% it's still red
imshow(outpict)

% show that the histogram has a hole in it
subplot(2,1,1)
imhist(h)
subplot(2,1,2)
imhist(hnew)

% inspect that part
countsnew = imhist(hnew,nbins); % need to call imhist() twice
countsnew(20:30) % yes they're zero

ans = 11x1

0 0 0 0 0 0 0 0 0 0

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% show how the hues were shifted
comp = [im(1:250,:,:); im2uint8(outpict(251:end,:,:))];
imshow(comp)