How can I reset the h and s channels?

I have an image in hsv and I would like to set the h and s channels to 0 in order to have the desaturated image. How can I do?

Answer 1

[Walter Roberson]

NewImage = hsvimage;
NewImage(:, :, 1:2) = 0;

However if your purpose is to desaturate then you should only assign to the s channel, 2

[matlab9000]

ok, but how come if I write this code, that is the desaturated image, I do not get out of the desaturated image (ie gray), but it comes out with colors?

img = rgb2hsv(imread('peppers.png'));
img(:,:,2) = 0;
imshow(img);

//image is output

[Walter Roberson]

You forgot to convert back to rgb before displaying.

[matlab9000]

Thanks !!!