[Scilab-users] need help with image post processing

[Stéphane Mottelet]

Another possibility: compute the connected components of the green plane 
bitmap image and keep only the largest one. You can use imlabel then 
imblobprop (in IPCV):

im=im2bw(imread("G.jpg"),0.5); // I took a screenshot of your G plane image

clf
subplot(1,2,1)
imshow(im)

[im_labeled,n] = imlabel(im);
[a,bb,c] = imblobprop(im_labeled);
[as,k]=gsort(a);
for i=2:n
     im(im_labeled==k(i))=0;
end

subplot(1,2,2)
imshow(im)

S.

Le 15/07/2020 à 20:39, P M a écrit :
> Stéphane,
>
> Thanks for the hint.
>
> This is nice for dots being completely surrounded by the green area.
>
> In general there might be cases, where the dots are part of the red 
> and part of the green area.
>
> The result would than be like this:
>
> grafik.png
>
> Appreciate your input.
> Philipp
>
> Am Mi., 15. Juli 2020 um 18:21 Uhr schrieb Stéphane Mottelet 
> <stephane.mottelet at utc.fr <mailto:stephane.mottelet at utc.fr>>:
>
>     Hello,
>
>     Maybe this is not relevant, but if the green region is garanteed
>     to be always simply connected, you just have to fill holes in your
>     absdiff(G,B) image (imfill function in IPCV).
>
>     S.
>
>
>     Le 15/07/2020 à 17:58, P M a écrit :
>>     Dear Scilab community,
>>
>>     Thanks to Antoine's functions I am able to read tif-files as M x
>>     N x Channel - matrix.
>>
>>     Px values are:
>>
>>     red       =>  255, 0, 0
>>     green    =>  0, 255, 0
>>     black     =>  0, 0, 0
>>     white     =>  255, 255, 255
>>
>>     Now:   I want to only keep the green pixel values.
>>     This can be done due to:  G = img(:,:,2);
>>
>>     However, this plane does also include the white pixels, since
>>     white has a pixel value of 255 in the green plane.
>>     This is Ok, as long as the white pixels are surrounded by the
>>     green area.
>>
>>     However there are also white pixels in the red and black area.
>>     These white pixels should be set to 0.
>>
>>     I started to work with differential images , but somehow I can
>>     not get around the problem.
>>
>>     Please find below an example of my output.
>>
>>     upper line:    RGB; R-plane; G-plane ; B-plane
>>
>>     As you can see, the G-plane contains white pixel (2 dots), which
>>     are within the red-area
>>     The desired output would be to have the G-plane without the 2 dots.
>>
>>     Any Idea?
>>
>>     Best Regards,
>>     Philipp
>>
>>
>>
>>     grafik.png
>>
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>     -- 
>     Stéphane Mottelet
>     Ingénieur de recherche
>     EA 4297 Transformations Intégrées de la Matière Renouvelable
>     Département Génie des Procédés Industriels
>     Sorbonne Universités - Université de Technologie de Compiègne
>     CS 60319, 60203 Compiègne cedex
>     Tel : +33(0)344234688
>     http://www.utc.fr/~mottelet  <https://antispam.utc.fr/proxy/1/c3RlcGhhbmUubW90dGVsZXRAdXRjLmZy/www.utc.fr/~mottelet>
>
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-- 
Stéphane Mottelet
Ingénieur de recherche
EA 4297 Transformations Intégrées de la Matière Renouvelable
Département Génie des Procédés Industriels
Sorbonne Universités - Université de Technologie de Compiègne
CS 60319, 60203 Compiègne cedex
Tel : +33(0)344234688
http://www.utc.fr/~mottelet

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