How to speed this up?

Question

Mario 2018-8-18

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/415371-how-to-speed-this-up

评论： Mario 2018-8-18

采纳的回答： Image Analyst

在 MATLAB Online 中打开

Hello,

I am trying to optimize (speed up) my code and I was wondering if someone can help me with this.

In my code I got used to using for loops (even though I know they are not computationally efficient), and a small part of my code is below which I want to address first:

subplot(1,3,2),imshow(CT (:,:,bri), []); % show image # 20 from CT dataset
hFH = imfreehand(); % Create a binary image ("mask") from the ROI object
%%code starts from here
binaryImage = hFH.createMask;
close ();
close all force
[sizex, sizey, sizez]= size(binaryImage);
for ir=1:Br_snimaka
   blank = zeros(sizex,sizey,sizez);
    for i=1:sizex
        for j=1:sizey
            for d=1:ir
                blank(i,j,d)=binaryImage(i,j,1);
            end
        end
    end
end
CT(~blank) = 0;

The input (CT) is a dataset of CT images which are passing through this code. And the idea is to draw one mask and then pass that mask (ROI area) to all other images.

Any suggestions on how to speed this up?

Thanks in advance!

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Answer 1

Image Analyst 2018-8-18

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/415371-how-to-speed-this-up#answer_333264

在 MATLAB Online 中打开

Try this instead of the for loop to do your masking:

binaryImage = hFH.createMask;
% Mask the image using bsxfun() function to multiply the mask by each channel individually.
CT = bsxfun(@times, CT, cast(binaryImage , 'like', CT));