imcontrast - how to return the level values?

7 Ansichten (letzte 30 Tage)
arnold
arnold am 9 Dez. 2013
Bearbeitet: Cris LaPierre am 24 Jul. 2023
Hi!
I have been using imcontrast
quite a bit over the years as it is a very handy tool for users to visibly adjust the threshold level for image segmentation. Here is my standard function:
im2bw(fn_image_leveling(testimage), 0.5);
function out = fn_img_leveling(img)
h=figure;
imagesc(img); colormap(hot);
axis image;
uiwait(imcontrast); % set levels
out = getimage(h);
out(out==0)=nan;
close(h);
In my current project I want to let the user set a threshold value for the first image and then apply it to many images. I can't seem to figure out though, how to get the threshold value a user sets using imcontrast. The way I see it the function is not intended to be used like this though :(
Does anyone have an idea how to solve this? I really need a live preview of the adjustable thresholding for it to work.
kind regards, Arnold

Antworten (3)

Mitchell Anderson
Mitchell Anderson am 30 Okt. 2018

I find them buried deep in the object hierarchy.

        temp = imcontrast;
        ContrastMax = str2num(temp.Children(1).Children(3).Children.Children(2).Children.Children(2).Children(2).String)
        ContrastMin = str2num(temp.Children(1).Children(3).Children.Children(2).Children.Children(2).Children(5).String)

Image Analyst
Image Analyst am 11 Dez. 2013
See my interactive thresholding app: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862 It returns the values after which you can use them in imadjust() to process the rest of the images in batch mode.
Otherwise it looks like you'll have to ask the user to input the values via inputdlg() so that you can then use imadjust().

Cris LaPierre
Cris LaPierre am 24 Jul. 2023
Bearbeitet: Cris LaPierre am 24 Jul. 2023
A slightly simpler way to access them is to use findobj with the Tag string:
htool = imcontrast;
contrastMin = findobj(htool,'Tag','window min edit').String
contrastMax = findobj(htool,'Tag','window max edit').String
Other tags of interst might be
  • 'window center edit'
  • 'window width edit'

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by