problem with size of images

I have the following code

imglist=dir('*.tif');   %list of the .tif images
thresh = zeros(512,512,200);
level = zeros(200);
edges_canny = zeros(512,512,200);

for i=1:length(imglist)

    name=imglist(i).name;
    A=imread(name);
    level(i)=graythresh(A);   %level of the threshold for Otsu method
    BI=im2bw(A,level(i));    %converts the grayscale image to a binary image
    thresh(:,:,i)=BI;    %save the thresh image

 %   BIedge=edge(A,'Canny'); %edge detection with Canny method
 %   edges_canny(:,:,i)=BIedge;

    f=figure;set(f, 'Visible', 'off');
    imshow(BI);
    saveas(f,sprintf('threshbg8B-3.2_15k_0d5_base_x=0mm_y=0mm_C001H001S000100000%d.tif',i))
  %  k=figure;
  %  imshow(imfill(edges_canny(:,:,i),'holes')); %fill the holes
  %  saveas(k,sprintf('canny8B-3.2_15k_0d5_base_x=0mm_y=0mm_C001H001S000100000%d.tif',i))

end
images=dir('threshbg8B-3.2_15k_0d5_base_x=0mm_y=0mm_C001H001S000100000*.tif');
n = {images.name}';
[~,ii] = sort(str2double(regexp(n,'(?<=threshbg8B-3.2_15k_0d5_base_x=0mm_y=0mm_C001H001S000100000)\d*(?=\.tif)','match','once')));
images = images(ii);
close all

It reads a series of images and then thresholds them. My question is:

whos BI
Name        Size              Bytes  Class      Attributes

BI        512x512            262144  logical              

 C=imread(images(1).name);
 whos C
  Name        Size                  Bytes  Class    Attributes

C         900x1200x3            3240000  uint8

Why does this happen? C and BI are supposed to be the same. I just put all BI's in a list

[Adam]

Which version of Matlab are you using?

Right at the top of the help for saveas it says:

'Starting in R2016a, the size of saved figures match the size of the figure on the screen by default. For more information, see Printed Figure Size: Print or save figures that match size of the figure on the screen by default.'

[Efstathios Kontolatis]

I'm using R2015b version

[Adam]

I'm not able to view the help for R2015b, but it sounds like it may still be doing that anyway.

Answer 1

[Geoff Hayes]

Efstathios - you are saving a figure to a file (rather than an image) and so I think that it is reasonable that C is of a different size than BI. In fact, if you display C using imshow, you may see a white border around your image with an axes.

If you wish to save BI to file, then use imwrite as

 imwrite(BI, sprintf('threshbg8B-3.2_15k_0d5_base_x=0mm_y=0mm_C001H001S000100000%d.tif',i));