matlab code overload (busy) and not doing what it's supposed to do

Hi

I have written an image acquisision and proccessing code which is invoked every time a timer object stops running, or not responding.

the whole project consists 3 fuctions: 1)timer definition 2)image acquisition 3)image processing

when Im debugging the program, everything is working great. when Im making an executable of my program usin the deployment tool, it starts, but closes itself, or not doing anything. if it doesnt close, it just overloads my cpu (to 100%).

The algorithm's run time is infinite, because I am running the timer at a 'fixed spacing' running mode.

the codes are:

1)

function []= timer_me()
    clear
    clc
    close all
    %a=imread('tire.tif');
    %imshow(a);
    global oldfile;
    path = 'C:\MATLAB PROJECTS\dirtest';
    test=dir(path);
    oldfile=test(size(test)).name;
    out = timerfind('Name', 'ReadImageTimer');
    if(size(out)==0)
        t = timer('Name','ReadImageTimer',...
            'ExecutionMode', 'fixedSpacing',...
            'TimerFcn',@readimage,...
            'Period',0.5 );

          start(t);
      end

      while(1);
  end-----------------------------

2)

function [ ] = readimage(arg1, arg2, arg3)
    path = 'C:\MATLAB PROJECTS\dirtest';
    test=dir(path);
    filename=test(size(test)).name;

      global oldfile

      if(~strcmp(oldfile, filename))%IS THE OLDEST FILE IN THE 
                                     %DIRECTORY NEW?
          i=imread([path '\\' filename]);
          imshow(i);
          [hit]=coloralg(i);
          oldfile=filename;
          hit
           subplot(2,1,1), imshow(i);
          if(hit == 1)
              subplot(2,1,1), imshow(i);
              xlabel('hit!')
              ylabel('hit!')

          else
              xlabel('miss!')
              ylabel('miss!')

          end

      else
          a='same'
      end
     % start(timer) 
  end
-------------------------

3)

function [hit] = coloralg(x)
%type=3;                                          %in the actual func will get 1/2/3 according to R/G/B
%[x]=imread('black_red.jpg');
%x=data;
subplot(2,1,1), imshow(x), ylabel('before');
xred=x(:,:,1);
%xgreen=x(:,:,2);
%xblue=x(:,:,3);

[numr,numc,null]=size(x);

quant=90;

for r=1:numr
    for c=1:numc
        if x(r,c,1)>110
          if  x(r,c,2)<230
             if  x(r,c,3)<230
                x(r,c,:)=255;
             else
                 x(r,c,:)=0;
             end
          else
              x(r,c,:)=0;
          end
          else
            x(r,c,:)=0;
        end
    end
end

%xafterred=x(:,:,1);
%xaftergreen=x(:,:,2);
%xafterblue=x(:,:,3);
subplot(2,1,2), imshow(x), ylabel('after ');
middlex=round(size(x)/2);
middlexr=[middlex(1),middlex(2)];
measurepointr = [middlexr(1), middlexr(2) , 1];
wtf=x(measurepointr(1),measurepointr(2),1)
    a=imread('tire.tif');
    imshow(a);
if(wtf == 255)
    hit = 1;
else
    hit = 0;
end
------------

Can somebody help me please?

Matar Maoz

Answer 1

[Jan]

Avoid using "path" as name of a variable. This possibly shadows the important function PATH.

Using == with vectors in an IF condition is not clean:

out = timerfind('Name', 'ReadImageTimer');
if(size(out)==0)

It works here, but prefer:

if isempty(out)

Using CLEAR directly after the function header is meaningless. So better omit it.

I do not think that this does what you expect:

test = dir(path);
filename = test(size(test)).name;

"size(test)" replies a vector. I assume you want "length(test)". But even then, the assumption, that the last file is the oldest is fragile. The reply of the DIR command is sorted alphabetically, but even this is not documented. Better use the datenum's replied by DIR also to find the oldest file.

This is a cruel method to waste energy:

while(1)
end

Because this loop is called infinitely, the timer's callback has no chance to be invoked. At least insert a DRAWNOW, but PAUSE(0.1) would be more friendly. I'd avoid the unnecessary increase of complexity of using a TIMER and use the loop in the main program directly:

while 1
  pause(0.5);
  readimage;
end

BTW.: The 3 inputs of readimag() are not used anywhere. If you use a modern Matlab version, some warning should appear.

Finally I cannot believe that this program "runs great" when debugging.

[matar maoz]

Does the argument in *paus(0.5)*

while 1

pause(0.5);

readimage;

end

has anything to do with the time set in my timer?

what is that for?

Matar

[Paulo Silva]

pause(0.5) pauses execution for 0.5 seconds before continuing

while 1 does a loop that never stops unless you press Crtl+C, it's alway a bad idea to use it, read Jan comments on that subject

That code is a never ending loop that waits 0.5 before executing the readimage function and waits 0.5 again...

[matar maoz]

so I can refrain from using the timer completely?

[Paulo Silva]

like Jan said you can use the loop and pause instead of the timer, each way has some different problems.