Re: Picking yellow and red tones from RGB images using Matlab Image Processing Toolbox

I dont have any available code to give you, but i can give you some simple
steps that you can follow...

a) the red values you can get form the R-channel of the RGB signal, but i
guess that you are only interested in a certain red and not in pixels of ret
that exist in other colors as well. Even thougn filtering the small objects
could solve this problem, there is a way to seperate just the red valus that
you need.
b) Convert the RGB images that you have in YUV image, so each pixel on your
image is now represented in as luminane, and angle and a distance.
c) Print your image on an UV map (the Y is luminance and you can leave it
out). In short for each pixel of the original image, print a white pixel on
the UV map according its YUV angle and distance.
d) when you are done with this , you should see several blobs of white on
the UV map. This blobs are the concetrations of each color in the image.
e) see what UV angle and distance the particles that you are interested
have. Then threhold the original image acording this angles and distances
and you have the images that you require.

hope i helped

Dimi

"ImageProcessing" <ImageProcessing@xxxxx> wrote in message
news:seAOg.109729$_J1.836897@xxxxxxxxxxxxxxxxxxxxx
Does anybody know which code should I implement, using Matlab Image
Processing Toolbox, to extract separately the red and yellow tones from an
RGB image, making all other pixels black?
Then I need to threshold the two image obtained, the reds one and the
yellows one, to put them in binary mode and then reconstruct only one
image
from the two binary images.
I have this practical problem: I have some frames in JPEG format, taken
from
a video file, that contain red and yellow glass microbeads. The background
is blue. I need to extract only red and only yellow microbeads,
respectively, from the images, in such a way to perform certain operation,
like concentration measures in some areas of the images.
Does anybody know also how to obtain a "pixelate" effect (typical of
video-editing softwares like Sony Vegas) for the RGB images in Matlab?
Thanks in advance.



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