Looping through a matrix with unknown dimensions

function [r,g,b] = Distant_Pixel(n)
pixels= gallery('integerdata',54,[1,n,3],42);
[R,G,B] = Median_Pixel(n);
r = Pixel_Distance([R,G,B],[pixels(1,1),pixels(1,1,2),pixels(1,1,3)])
g = Pixel_Distance([R,G,B],[pixels(1,2),pixels(1,2,2),pixels(1,2,3)])
b = Pixel_Distance([R,G,B],[pixels(1,3),pixels(1,3,2),pixels(1,3,3)]) 
end

Median_Pixel and Pixel_Distance are functions.

Since n will change depending on input. How do I fix the pixels matrix so that it works with any input of n

[pixels(1,1),pixels(1,1,2),pixels(1,1,3)] -- ?

[Walter Roberson]

You current code works provided that n is at least 3.

It is not clear what else you would like it to do?

[Bubbles Lol]

Yes but n is changing. So Since n is changing how do I adjust my code?

[Walter Roberson]

What would you like it to do differently with different n values?

Your current code takes pixel distance to three particular pixels . Provided that n is at least 3, there is no obvious reason why that would change. Do you need to account for the possibility that n is 0, 1, or 2?

[Bubbles Lol]

Yes, and i was wondering how I would do this.

[Rik]

It is considered extremely rude to edit away your question. You're getting free help from strangers, the least you can do is to leave it up for potential future people with similar issues.

[John D'Errico]

You insult the people who tried to help you by editting away your question, and you make it useless for anyone else to ever learn from the responses. We have asked the site admins to restore it.

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Walter Roberson]

function [r,g,b] = Distant_Pixel(n)
    pixels= gallery('integerdata',54,[1,n,3],42);
    [R,G,B] = Median_Pixel(n);
    r = []; g = []; b = [];
    if n >= 1
      r = Pixel_Distance([R,G,B],[pixels(1,1),pixels(1,1,2),pixels(1,1,3)]);
    end
    if n >= 2
      g = Pixel_Distance([R,G,B],[pixels(1,2),pixels(1,2,2),pixels(1,2,3)]);
    end
    if n >= 3
      b = Pixel_Distance([R,G,B],[pixels(1,3),pixels(1,3,2),pixels(1,3,3)]) 
    end
end

[Bubbles Lol]

The input of the function is a 1*n*3 array. Containing rgb values. I want to find the most distant rgb pixel values from those that are provided in the array. So how would I do this? and n can be any number. Thanks

[Walter Roberson]

We do not know what your function Pixel_Distance does.

It is not clear what the most "distance" rgb values means in this situation, since you appear to be talking about 3 different values

Given a set of pixel values, you can take the mean or median . Now for any one median component (say the G), check to see whether the component is above or below 1/2 of the maximum possible value (e.g., 128 if the values are uint8). If the component is below 1/2 of the maximum possible, then the most distant value is the maximum possible value (e.g., 255); if the component is above 1/2 of the maximum possible, then the most distant value is the minimum possible value (e.g., 0)