Identify the walls, floor and the ceiling and paint each one separately

Hello.

I intend to write code that detect the walls, floor and the ceiling and paint each one separately.

this is my code and I detected H,V lines using Hough transform from snapshot of webcam video.

function app2()

% Set-up webcam video input
vid = videoinput('winvideo', 1);

%% Set parameters for video
% Acquire only one frame each time
set(vid,'FramesPerTrigger',1);
% Go on forever until stopped
set(vid,'TriggerRepeat',Inf);
% % Get a grayscale image
% set(vid,'ReturnedColorSpace','grayscale');
triggerconfig(vid, 'Manual');

%% set up timer object
TimerData = timer('TimerFcn', {@FrameRateDisplay,vid},...
    'Period',1,'ExecutionMode',...
    'fixedRate','BusyMode','drop');

% Start video and timer object
start(vid);
start(TimerData);

flushdata(vid); % to clear memory
% Clear everything
stop(TimerData);
delete(TimerData);
stop(vid);
delete(vid);

imaqreset;


% This function is called by the timer to display one frame of the figure

function FrameRateDisplay(~,~,vid)
% persistent IM;

% trigger(vid);
% I=getdata(vid,1,'uint8');

NumberFrameDisplayPerSecond=5;

while(vid.FramesAcquired<=NumberFrameDisplayPerSecond)
    
    I = getsnapshot(vid);
    IM = rgb2gray(I);
    
    %% Inhancement Image
    
    IM = imbilatfilt(IM,...
        'degreeOfSmoothing',0.01*diff(getrangefromclass(IM)).^2,...
        'spatialSigma',1);
    IM = edge(IM,'canny');
    dilatedImage = imdilate(IM,strel('disk',1));
    IM = bwmorph(dilatedImage,'open');
  
    %% Perform Hough Transform
   
%     [H, theta, rho]=hough(IM);
    [H, theta, rho] = hough(IM,'Theta',-90:90:89,'RhoResolution',2);
    
    %% Find Hough Peaks
    
%     Threshold = 0.4*max(H(:));
%     p = houghpeaks(H,10,'Threshold',Threshold);
    p = houghpeaks(H,10);
    
    %% Find Lines
    
    FillGap = 10;
    MinLength = 20;
    
    lines = houghlines(IM,theta,rho,p,...
        'FillGap',FillGap,...
        'MinLength',MinLength);
    
    %% Show Result
    
    figure;
    
    imshow(IM)
    hold on;
    for k=1:numel(lines)
        
        Color = [0 1 0];
        
        Start = lines(k).point1;
        End = lines(k).point2;
        plot([Start(1) End(1)],[Start(2) End(2)],...
            '-','LineWidth',1,'MarkerSize',8,'Color',Color);
        
       
    end
    
end

now, I want to know

1) how to improve H,V lines detection? (for example the walls detection)

2) how to color walls?