Histogram problem. How to solve?

Good evening, I have the following code to generate the histograms and to calculate the values, and appear in the text boxes:

function calc_val_Callback(hObject, eventdata, handles)
global a;
global bmax bmin bmed;
b = rgb2gray(a); %transforma a figura em escala cinza
axes(handles.hist_gray); %ativa eixos
[counts1,binLocations1] = imhist(b); %calcula ordenadas e abcissas do histograma
bmax = max(max(b));
bmin = min(min(b));
bmed = mean(mean(b));
imhist(b); %desenhar histograma
ylim([0 bmax]); %limita ordenadas entre 0 e máximo
set(handles.max,'String',bmax);
set(handles.min,'String',bmin);
set(handles.med,'String',bmed);

global cmax cmin cmed;
c = im2bw(a); %transforma a figura em escala cinza
axes(handles.hist_bw); %ativa eixos
[counts1,binLocations1] = imhist(c); %calcula ordenadas e abcissas do histograma
cmax = max(max(c));
cmin = min(min(c));
cmed = mean(mean(c));
imhist(c); %desenhar histograma
ylim([0 bmax]); %limita ordenadas entre 0 e máximo
set(handles.maxi,'String',cmax);
set(handles.mini,'String',cmin);
set(handles.medi,'String',cmed);

Just get the gray scale histogram and the values of this histogram. But if export the data to excel, appears the data of the two histograms. In annex shows what appears.

[John D'Errico]

https://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup#answer_18099

[Image Analyst]

I don't know exactly what the problem is. And you didn't show the code where you are exporting something to Excel, like with xlswrite() or ActiveX commands so how can we debug why two histograms are being sent to Excel???

[Catarina Leitão]

function export_Callback(hObject, eventdata, handles)

global a;
global bmax bmin bmed;
global cmax cmin cmed;

gray = [bmax; bmin; bmed];
bw = [cmax; cmin; cmed];

      xlswrite ('Resultados.xlsx', gray, 'Resultados', 'C3:C5');
      xlswrite ('Resultados.xlsx', bw, 'Resultados', 'D3:D5');
      winopen ('Resultados.xlsx');

[Image Analyst]

It looks like it should work. You will probably have to upload the m file and .fig file, and the image(s) so we can try it ourselves.

[Catarina Leitão]

The .fig and .m files are attached.

Answer 1

[Walter Roberson]

The result of

c = im2bw(a);

is a logical array. min() and max() of those are 0 and 1, and there are no other values, which is why the imhist(c) is so boring. Meanwhile min() and max() applied to a logical array give logical results. You cannot set the string() property of a uicontrol to a logical value.

Easiest way to fix your code:

c = double(im2bw(a));