MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

# Color detection and display its name

Asked by SARBE on 20 Jul 2012

Color detection project

• take colors in circles or squares
• print it
• take a photo of this print
• then put it in your code for color detection
• It should be able to display the name of that color

I have started this project with very simple concept of masking. But colors exists in hundreds or thousands of shades. In my project code should be able to detect any shade and any color. I am thinking to use the concept of Euclidean distance to find the distance of color from origin, but i can not really do it.

Here is the code i used. it detects only four colors but from one image only.

```%------------------------------------
% Read the image into an array.
filename=input('Input the filename of the image>');
%------------------------------------
% Display the original image.
subplot(2, 3, 1);
imshow(RGB);
title('Original RGB Image');
```
```yellowMask = colorDetectHSV(RGB, [0.2 0.9 0], [0.05 0.05 0.05]);
redMask =colorDetectHSV(RGB, [1 1 1], [0.1 0.2 0.2]);
blueMask =colorDetectHSV(RGB, [0.6 0.5 0.6], [0.2 0.3 0.4]);
% Or can try this for blue color:
% blueMask =colorDetectHSV(RGB, [1 0.5 0], [0.4 0.4 0.3]);
greenMask =colorDetectHSV(RGB, [0.369 0.786 0.769], [0.2 0.2 0.2]);
```
```% Display them.
subplot(2, 3, 2);
subplot(2, 3, 3);
subplot(2, 3, 4);
subplot(2, 3, 5);
```

Christian Lenz on 20 Jul 2012

I don't quite well understand your question... Every color has allready a specific value in your RGB-image. Try:

``` RGBimg = imread( ... );
RGBimg = double( RGBimg );
Rimg = RGBimg ./ max(max(max( RGBimg ) ) );```
SARBE on 22 Jul 2012

actually this code is able to detect only four colors. i don't know how to expand it so that it can detect a number of colors.

Walter Roberson on 22 Jul 2012

Did you look at the work of John D'Errico, or of Image Analyst ?

## Products

Answer by Walter Roberson on 20 Jul 2012

Euclidean distance is not enough. Look in the File Exchange for John D'Errico's Fuzzy Color Detection.

But if your task really is to "detect any shade and any color", you should consider giving up before you start any development. Seriously. What you want to do cannot reliably be done. There is no scientific definition for what each color is, or where one shade ends and another begins. And color perception is personal, not absolute. See http://blog.xkcd.com/2010/05/03/color-survey-results/