isthisaface.m

基于MATLAB的人脸检测程序

function [autocorr, startx, starty, mfit, bwmodel_rot] = isThisAFace(mult, model,ly,wx,cx, ...
                                                  cy, angle)


  model_rot = imrotate(model,-angle,'bilinear');
  % Use the frontal model to do the comparison
  % model_rot = imresize(model_rot,[ly wx],'bilinear');

  [l,r,u,d] = recsize(model_rot);
  model_rot=imcrop(model_rot,[l u (r-l) (d-u)]);

 % figure;
 % imshow(model_rot);

  bwmodel_rot = zeros(size(model_rot));
  bwmodel_rot(find(model_rot > 1))=1;

  % Compute the center of the rotated face model

  [modx,mody] =center(bwmodel_rot);

  % Get the size of the rotated face model
  [morig, norig] = size(bwmodel_rot);

  startx = cx-modx;
  starty = cy-mody;
  endx = startx + norig-1;
  endy = starty + morig-1;

  mfit = zeros(size(mult));
  mfitbw = mfit & 0;

  [limy, limx] = size(mfit);
  startx = checklimit(startx,limx);
  starty = checklimit(starty,limy);
  endx = checklimit(endx,limx);
  endy = checklimit(endy,limy);

  % -------------------------------------------------------------
  % The following is to generate a new image having the same
  % size as the original one, but with the face of the model on it
  % rotated accordingly.


  for i=starty:endy,
   for j=startx:endx,
     mfit(i,j) = model_rot(i-starty+1,j-startx+1);
     mfitbw(i,j) = mfit(i,j);
    end;
  end;

 figure;
  imshow(mfit,[0 255]);

  % Get the autocorrelation value
  autocorr = corr2(mfit,mult)


% Verifies that the coordinate is between the image region.
function newcoord = checklimit(coord,maxval)

  newcoord = coord;
  if (newcoord<1) newcoord=1; end; 
  if (newcoord>maxval) newcoord=maxval; end;

% EOF.