How to get the intensity value of the flower

Answer 1

[Chunru]

im = imread("https://www.mathworks.com/matlabcentral/answers/uploaded_files/1136290/image.jpeg");
whos

  Name           Size                   Bytes  Class    Attributes

  cmdout         1x33                      66  char               
  im          3264x4928x3            48254976  uint8              

im = rgb2gray(im);      % intensity: gray level here; you may have other defination
imshow(im)
%hold on
viscircles([1200, 1000], 300);      % location of one flower

intensity = mean(im(1200+(-100:100), 1000+(-100:100)), 'all');  % average over 200x200 regions

intensity = 103.8454

[Malini]

Thank you . But I want the intensity value for all flowers irrespective of the position by removing background. The size of the flower varies.