Multiple image subtractions that is comming from live camera

I am capturing multiple images with the help of live camera and save into a file.Now i want to substract multiple images that is comming from live camera and store into a file.How is it possible in matlab and code.Thank You in advance.

Answer 1

[KSSV]

Let I1 and I2 be the image data obtained by using imread. Assuming they are of same dimensions:

I = I1-I2 ;

[Walter Roberson]

imsubtract effectively does the same thing, but can be more efficient as it has built in calls to intel graphics routines for this purpose that can take advantage of hardware.

[piku mandal]

KSSV,i want with in a loop. so how it possible? I dont want only substract 2 frames but also want to substract multiple frames with in a loop That i saved in a folder.

[KSSV]

Say you have 10 images,,,,you want to subtract all these images? And get one image?

[Walter Roberson]

R = 0 * I1;    %same size and data type as I1 but all 0

for K = 1 : numel(I1); R(K) = I1(K) - I2(K); end

[piku mandal]

for i=1:2(% for 2 frames)
  frame=getsnapshot(obj); (%taking snapshot from live camera and this is 1st frame)
  frame_pre=frame; (% keep it into previous frame)
  if i~=1
    frame_next=frame+1;(% next frame)
    sub_tracted_frame=imsubtract(frame_pre,frame_next);
    imshow(sub_tracted_frame);
  end
end

but why not working.... the resultant figure is whole blank and not shown as a matrix

[Walter Roberson]

obj = videoinput('macvideo', 1);  %use winvideo for Windows

obj.ReturnedColorSpace = 'rgb';   %you might need this

%then

for i=1:2 % (for 2 frames)
  frame=getsnapshot(obj); %(taking snapshot from live camera and this is 1st frame)
  if i~=1
    sub_tracted_frame=imsubtract(frame, frame_pre);
    imshow(sub_tracted_frame);
    drawnow();
  end
  frame_pre = frame;
end

[piku mandal]

Thank You Walter Roberson, sir.