color recognition using fft of image

[pravish]

hi .. i m new to frequency domain image filtering....i wanted to know....if i take the fft of the image how can i retrieve the coordinates of the pixel that has yellow color in the image....please help!

 

[just4me]

When you take a 2D fft of an image, you get information regarding spatial frequencies (i.e., how the pixel values are repeating from pixel to pixel), but there is no information regarding color. So you cannot use FFT for this purpose.

Instead what you can do is, in the spatial domain "yellow" color corresponds to certain values of R,G,B. Check each pixel if they belong to this range. If yes, then its a yellow pixel otherwise it is not.

 

[Robinenemy]

Hello

This can be done at RGB level directly.

image=input('Enter the file name : ','s');
RGB = imread(image,'jpg');% only Jpeg images

R = RGB,:,1);
G = RGB,:,2);
B = RGB,:,3);
%Sepetares the three components of the image

Yellow is formed by Red and Green combination
accordingly we can find the distribution of yellow pixels in an image.

 

[Robinenemy]

Hello

This can be done at RGB level directly.

image=input('Enter the file name : ','s');
RGB = imread(image,'jpg');% only Jpeg images

R = RGB,:,1);
G = RGB,:,2);
B = RGB,:,3);
%Sepetares the three components of the image

Yellow is formed by Red and Green combination
accordingly we can find the distribution of yellow pixels in an image.