## Does anyone do research on structured light? How to get a good edge detection?

### john (view profile)

on 10 May 2013
Latest activity Commented on by Camilo

### Camilo (view profile)

on 13 Aug 2018
My research recently is focus on using color stripe to detect 3d model. I generate a color stripe using De Bruijn sequence. But the edge detection is not as good as I expected.I am afraid this image could not be edge detected well, it is the first important step to process! How to get a good image?My aims is to detect the edge between color stripes?
%%initialize
clear;close all;clc;
I2 = rgb2gray(I);%I2 gray image
I3=I2;
figure(1);
image(I);
axis image;
N=size(I);
%Notice our stripe is vertical, so we check every column to detect edges.
R=I(:,:,1);
G=I(:,:,2);
B=I(:,:,3);
%%edge detection
%threshold
TS=10;
for i=1:N(1) %row
for j=2:N(2)
Defference=abs(R(i,j)-R(i,j-1))+abs(G(i,j)-G(i,j-1))+abs(B(i,j)-B(i,j-1));
if(Defference>TS)
I2(i,j-1)=255;
end
if((i<510)&&(i>498))
I2(i,j-1)=255;
end
end
end
%%get a part of the image and show its RGB content in a graph.
set(1,'color',[1 1 1]);
title(['input 2 points，get a rectangular, show its RGB curve' num2str(1)]);
% Use ginput to select corner points of a rectangular
% region by pointing and clicking the mouse twice
p = ginput(2);
% Get the x and y corner coordinates as integers
sp(1) = min(floor(p(1)), floor(p(2))); %xmin
sp(2) = min(floor(p(3)), floor(p(4))); %ymin
sp(3) = max(ceil(p(1)), ceil(p(2))); %xmax
sp(4) = max(ceil(p(3)), ceil(p(4))); %ymax
% Index into the original image to create the new image
MM = I(sp(2):sp(4), sp(1): sp(3),:);
% Display the subsetted image with appropriate axis ratio
figure(2);
subplot(3,3,1);image(MM); axis image;title('the image extract');
hold on;
WW=40;
COnes=ones(WW);
CZeros=zeros(WW);
Mycolor=[0 0 0;0 0 1;0 1 0; 0 1 1; 1 0 0;1 0 1;1 1 0;1 1 1];
for i=1:8
subplot(3,3,i+1);
image(cat(3,Mycolor(i,1)*COnes,Mycolor(i,2)*COnes,Mycolor(i,3)*COnes));
title(num2str(Mycolor(i,1))+num2str(Mycolor(i,2))+num2str(Mycolor(i,3)));
end
N=size(MM);
RowMax=min(8,N(1));
ColumnMax=min(900,N(2));
x=1:ColumnMax;
figure(3);
for i=1:RowMax
subplot(RowMax,1,i);
y1=MM(i,1:ColumnMax,1);
y2=MM(i,1:ColumnMax,2);
y3=MM(i,1:ColumnMax,3);
plot(x,y1,'r');
hold on;
plot(x,y2,'g');
hold on;
plot(x,y3,'b');
end
%%show the edge detection result in gray mode,edge is showed in red line.
I4=cat(3,I2,I3,I3);
figure(4);
imshow(I4);
You can see in the background there are black lines seems like net. 'Rapid Shape Acquisition Using Color Structured Light and Multi-pass Dynamic Programming'.is the paper I based on.
This picture is I taken 2 days ago.My edge detection is totally failed. The key to success is to find each color transition through edge detection. But the line in background and the color cross talk is very serious!! Thank you very much.
It uses edge detection to find each color transition line.But it won't work well I guess.

Jaco Verster

### Jaco Verster (view profile)

on 23 Oct 2016
Hi John, I am currently also working on a similar project. Have you been able to solve the problem? Jaco
Tkingdom

### Tkingdom (view profile)

on 6 Dec 2016
Hi Jaco,I am studying on how to generate a color stripe using De Bruijn sequence. But I don't konw how to start. Can u do me a favour? Dean
Camilo

### Camilo (view profile)

on 13 Aug 2018
Hi John, I am currently also working on a similar project. Have you been able to solve the problem? Camilo