MATLAB: How can i get the minimum and maximum values of h,s and v of HSV image

Question

im working on a colour scale to determine the standard of my data(rgb images) and i have successfully converted my rgb image to hsv image. now to complete my colour scale, i need to find the range of each component of hsv by finding the minimum and maximum values for h, s and v of the converted image and display it in text form..but how do i do that?

i manage to find the min for RGB values but stuck on finding min and max of HSV values. below is some of my coding:

data=fopen('minvaluesRGB.txt','w+');
I_HSV = rgb2hsv(I_RGB);
slice_reshape=reshape(I_HSV,[],3);
[unique_RGB,m,n]=unique(slice_reshape,'rows');
minRGB2=sort(unique_RGB(:,:,1));
minRGB22=minRGB2(2,:);
[R]=minRGB22(:,1);
[G]=minRGB22(:,2);
[B]=minRGB22(:,3);
fprintf(data,'%f',[R]);
fprintf(data,'\n');
fprintf(data,'%f',[G]);
fprintf(data,'\n');
fprintf(data,'%f',[B]);
fprintf(data,'\n');

thanks.

Answer 1

Finding the min of the HSV channels is exactly the same as finding the min of the RGB channels, but in the HSV space:

%minimum of RGB channels:
Rchannel = I_RGB(:, :, 1); Rmin = min(Rchannel(:))
Gchannel = I_RGB(:, :, 2); Gmin = min(Gchannel(:))
Bchannel = I_RGB(:, :, 3); Bmin = min(Bchannel(:))
%minimum of HSV channels:
I_HSV = rgb2hsv(I_RGB);
Hchannel = I_HSV(:, :, 1); Hmin = min(Hchannel(:))
Schannel = I_HSV(:, :, 2); Smin = min(Schannel(:))
Vchannel = I_HSV(:, :, 3); Vmin = min(Vchannel(:))