finding number of pixels inside each circle
15 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Dhandapani.S
am 21 Jan. 2015
Kommentiert: Dhandapani.S
am 1 Feb. 2015
i am drawing circles of different radius on a jpg image. how to find the number of pixels in each circle. i have to compare the pixel distribution ratio in each circle
3 Kommentare
Akzeptierte Antwort
Image Analyst
am 26 Jan. 2015
I'm pretty sure I gave you the answer in your other question: http://www.mathworks.com/matlabcentral/answers/169093#comment_261946 How is this any different than that?
3 Kommentare
Image Analyst
am 26 Jan. 2015
Just try it and see. Create a mask for triangles with poly2mask().
xTriangle = [x1,x2,x3,x1]; % Make a list of the coordinates of the vertices.
yTriangle = [y1,y2,y3,y1];
[rows, columns, numberOfColorChannels] = size(yourImage);
binaryImage = poly2mask(xTriangle, yTriangle, rows, columns);
Weitere Antworten (1)
Thorsten
am 21 Jan. 2015
A well-known "approximation" is :-)
N = round(radius^2*pi)
You could also create a circle and count the pixels:
radius = 100;
x = [-radius: radius];
[X, Y] = meshgrid(x, x);
R = sqrt(X.^2 + Y.^2);
N = numel(find(R<=radius));
Both values are almost the same.
2 Kommentare
Thorsten
am 26 Jan. 2015
You can just use any other value for the radius, like
radius = 50;
and then compute the N to count the pixels in the circle of radius 50. Or what else do you need?
Siehe auch
Kategorien
Mehr zu Image Segmentation and Analysis finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!