Using scilab video processing toolbox and a laser pointer to "paint" a scene in realtime.

A little tic/toc ery has shown that without an image draw scilab can process 3 fps. So here’s a loop unrolled version that delays image rendering till 3 dots have been drawn.
//”paint” a scene with a laser pointer in realtime
//speed of update depends on speed of camera + processor

//could also easily be used on a video file

n = camopen();

for idx=1:15,

//give the camera time to auto white balance



im3prime = rgb2gray(im1);

//save our “primary scene”

im3 = im3prime; imshow(im3);

//show us our primary scene

r=x_message([‘Baseline Set’],[‘Ok’]);

//let us know when to laser pointer

for ido=1:15, mask = zeros(im3);

//clear out our mask quickly

for idx=1:3,

//or however many frames/sec you can process



//read a frame in

//subtract the greyscale current image from the primary scene

//then take that logical array, convert to numerical and

//use it as a mask over im3

mask = mask + bool2s(imsubtract(rgb2gray(im2), im3prime) > 50);




im3(mask == 1) = 255;