Shape Recognition

differentiate Square, Rectangular, Circle from others

Description

Objective
---------
The program should recognize objects like circles, rectangles, and squares from the input image.

Introduction
------------
This is a shapes classifier based on the properties of each shape, like roundness, ratio of dimensions, centroid,?etc

In this classifier we will recognize only shapes like circles, rectangles, and squares from the input image.
So, we will concentrate on the steps we will follow to recognize those shapes from any input image.

We have seven steps:
1 - Read the RGB (colored) image in from user.
2 - Convert image from (RGB) colored to gray image.
3 - Threshold the image (convert gray image to binary image).
4 - Invert the binary image (in order to speed up the time of processing).
5 - Find the boundaries concentrate.
6 - Determine shapes properties (ratio of dimensions, roundness).
7 - Classify shapes according to its properties.

Input
-----
RGB image have the shapes to recognize.

Output
------
The RGB image with shapes recognized and labeled.

• Required Products: Image Processing Toolbox
• MATLAB release: MATLAB 7.0.1 (R14SP1)

[michael scheinfeild]

this is very good example how to classify shapes
i think to add also elipse detection
i need to think about it
thw width not equal height
and also it not fill the bounding box but it is true to the other not detected shape so i want to add more criterions

[b c]

good

[Tariq Javid]

Excellent, as circle shape classification approach inspired me to work on hexagon generation from an identified circle in an image

[mahesh m]

 

[Diego Barragán]

 

[Hammad Arshad]

Does not work with images taken by a camera
Gives a lot of squares and circles where it is not needed

[Ahmed Samieh]

do you know what is the problem ?
the problem is, camera images has noise, so you need to reduce the noise (image enhancement)befor the recognation

[Tariq Javid]

Good work! This has inspired me a lot. I found it useful for error/noise free autonomous inspection. Another application area may be atifically created images.

[imesha kuruppu]

 

[Ahmed Samieh]

FAQ:
Q1 - In your program, what do you mean by
Classify Shapes according to properties
% Square = 3 = (1 + 2) = (X=Y + Extent = 1)
% Rectangular = 2 = (0 + 2) = (only Extent = 1)
% Circle = 1 = (1 + 0) = (X=Y , Extent < 1)
% UNKNOWN = 0
---------------
A1 -
the answer of (X == Y) ---> true or false ---> 1 or 0
X is the X-dimension and Y is the Y-dimension
so i check if X-dimension equal Y-dimension of the object
if true it will give 1 else it will give 0
in 8-bit binary integer it will be 00000001 or 00000000 (equ 1)
ok....
again with (Extent = 1) ---> 1 or 0
multiply the result by 2 will give 2 or 0
in 8-bit binary integer it will be 00000010 or 00000000 (equ 2)
ok...
adding the result of (equ 1) and (equ 2) give
 
    00000011 (3) ---> 00000010 (2) (Extent equal 1) + 00000001 (1) (X-dimension equal Y-dimension)
or 00000010 (2) ---> 00000010 (2) (Extent equal 1) + 00000000 (0) (X-dimension not equal Y-dimension)
or 00000001 (1) ---> 00000000 (0) (Extent not equal 1) + 00000001 (1) (X-dimension equal Y-dimension)
or 00000000 (0) ---> 00000000 (0) (Extent not equal 1) + 00000000 (0) (X-dimension not equal Y-dimension)

[Hrushikesh Kulkarni]

extremely good job
and quite inspiring work

thanks

[kevin scott basinio]

its good

[RAJALAKSHMI ALAGIAMANAVALAN]

Hi,I have interest to view this file.Thankyou.

[Aamir langah]

thank you very much for your contribution which is helpful for the most of students of image processing field

[aymen sellaouti]

Think you very much for your contribution

[Rocky Hurray]

 

[Nutthasit Laosuwan]

good

[chen cuicui]

 

[bharathi v]

nice to see this one .thank you

[Christian Stewart]

Its very useful for me. Can you tell me how Triangle can be recognized in similar way??

[long yi]

很好！

[Jun wan]

 

[vsrin2 srin]

Good program. I would like to output the black and white images (intermediate step) to a data file showing only 0 and 1's. how can i do it?

[Alireza Saberi]

nice

[Gül Begüm Semis]

this is a really great example.
I am working on an image processing / shape recognition project right now. the aim is to group some objects on conveyor where the object shapes are square,circle and rectangle.
i have 2 questions . the first one is that how can i write the code for a tringle recognition.
the second question is i am going to be doing the image processing from webcam shots. the code only workd with bmp files. how can i reduce noise in the shots ?

thank you very much

[LIM CZE SIANG]

How to mark outer circle such as square box or outer line for those shape detected?
Can the triangle formula be posted up?
Thanks

[abhi m]

I should recognise circle square rectangle but am struck... the code below is effecient in recognising circle but it is failing to recognise square and recatngle.. plz help me in improvising my code plz....

rgbImage = imread('test.jpg');
[rows columns numberOfColorBands] = size(rgbImage);
subplot(3, 2, 1);
imshow(rgbImage, []);
title('Original color Image');
set(gcf, 'Position', get(0,'Screensize')); % Maximize figure.

%STEP 2

%---------------------------------------------------Convert rgb image to grayscale-----------------------------------------

grayImage = rgb2gray(rgbImage);
subplot(3, 2, 2);
imshow(grayImage, []);
title('Converted to gray scale');

%STEP 3

%------------------------------------------------------Detection of edge by canny-------------------------------------------------------

cannyImage = edge(grayImage,'canny');
subplot(3, 2, 3);
imshow(cannyImage, []);
title('Canny Edge Image');

%STEP 4

%-------------------------------------------------------------dilation--------------------------------------------------------

windowSize = 5;
halfWidth = floor(windowSize/2);
dilatedImage = zeros(rows, columns);
for col = (halfWidth+1) : columns - halfWidth
    x1 = col - halfWidth;
    x2= col + halfWidth;
    for row = (halfWidth+1) : rows - halfWidth
        y1 = row - halfWidth;
        y2 = row + halfWidth;
        dilatedImage(row, col) = max(max(cannyImage(y1:y2, x1:x2)));
    end
end

%Displaying the dilated image

subplot(3, 2, 4);
imshow(dilatedImage, []);
caption = sprintf('Dilated with a window size of %d',windowSize);
title(caption);

%STEP 5

%------------------------------------------------------------Erosion-------------------------------------------------

windowSize = 5;
halfWidth = floor(windowSize/2);
erodedImage = zeros(rows, columns);
for col = (halfWidth+1) : columns - halfWidth
    x1 = col - halfWidth;
    x2= col + halfWidth;
    for row = (halfWidth+1) : rows - halfWidth
        y1 = row - halfWidth;
        y2 = row + halfWidth;
        erodedImage(row, col) = min(min(dilatedImage(y1:y2, x1:x2)));
    end
end

%Displaying eroded image

subplot(3, 2, 5);
imshow(erodedImage, []);
caption = sprintf('Eroded image with a window size of %d',windowSize);
title(caption);
[B,L] = bwboundaries(grayImage, 'noholes');

STATS = regionprops(L, 'all');

figure,
imshow(grayImage),
title('Results');
hold on
for i = 1 : length(STATS)
  W(i) = uint8(abs(STATS(i).BoundingBox(3)-STATS(i).BoundingBox(4)) < 0.1);
  W(i) = W(i) + 2 * uint8((STATS(i).Extent - 1) == 0 );
  centroid = STATS(i).Centroid;
  switch W(i)
      case 1
          plot(centroid(1),centroid(2),'wO');
          title('circle');
      case 2
          plot(centroid(1),centroid(2),'wX');
          title('rectangle');
      case 3
          plot(centroid(1),centroid(2),'wS');
          title('square');
  end
end
return

[yar131 Iaroslav]

Please help me. I am beginner at Matlab. How can I start this programm. I have the following error.

??? Input argument "test" is undefined.

Error in ==> Classify at 24
RGB = imread(test);

[Surya Rathore]

could you please tell me how to write 1st line of the program.that means how to pass sample,training,group of the image file. it will be better if you explain it through an example.

[peter veres]

Problems on starting problam , and no help after questioning...

[peter veres]

Ok, I am sorry for the first comment... It works for still images, does anybody knows how to take snapshot over web camera? Of course and use with this program?

[mohammad salah]

this response is for "yar131 Iaroslav". you type:

RGB = imread('test.bmp')

[Atif Anwer]

helpful for starters on image processing in matlab. Great work!

[Jason]

it‘s very good.

[am]

Thank you so much.

[omar Alhmouz]

Hi, nice work Ahamd, is triangle shapes included in the code?

[ahmed ismail]