Removing image outliers from average images using if loop?

Hi there, what I am trying to do is i have a set of averaged images, I more or less the position of the max value. I want to set up an if loop to then remove these images from the average image?

if true
imgindex = numim0:numimages
   imxstruct = readimx(fullfile(stemgating, sprintf('B%05d.im7', imgindex)));
   img = imxstruct.Frames{1}.Components{1}.Planes{1};                     
    FUNC=@(x)max(x(:));
     img1=medfilt2(img,[3 3]);              
   LIIimages{imgindex}= flip(imrotate((img1),-90),2)
end

LIIimages=cat(3,LIIimages{:});
meanimg=mean(LIIimages,3);                       
meanimg1=meanimg1+meanimg;                           
end
AverageImage=(meanimg1/(numimages+1numim0))