Overwritting problem in for loop

Question

DIMITRIOS THEODOROPOULOS 2019-3-16

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/450393-overwritting-problem-in-for-loop

评论： Jan 2019-3-18

I simply crop images and save them with a number.For example i have Grain #1,Grain #2,Grain #3.If i move to another image and crop further images i cannot create images Grain #4 ,Grain #5 etc and instead there are overwritten images...Here is my code.Where is my mistake??

clear all;
clc;
addpath(genpath('C:\Users\User\Desktop\TEI'));
imtool close all; 
k=input('How many times do you want to repeat the cropping?');
IMAGE = uigetfile('*.jpg','Pick an image');
A=imread(IMAGE);
figure,imshow(IMAGE);
folder=('C:\Users\User\Desktop\TEI\BEE_POLLEN _PROJECT\Scripts');
for i=1:k
  f = sprintf('Select a ROI and double click to crop #%d',i);
  uiwait(warndlg(f));
  [B, rect] = imcrop(A);
  baseFileName = sprintf('Grain #%d.jpg',i);
  fullFileName = fullfile(folder, baseFileName);
  baseFileName2 = sprintf('Grain #%d .jpg', (i+1));
  fullFileName2 = fullfile(folder, baseFileName2);
  if exist(fullFileName)     
    imwrite(B, fullFileName2);
  else
    imwrite(B, fullFileName);
  end
  if i==k
    f=sprintf('FINISHED!!');
    uiwait(warndlg(f));
  end
end

4 个评论
显示 2更早的评论隐藏 2更早的评论

dpb 2019-3-16

At least give it a go with the supplied hints..."nothing ventured, nothing gained!"

Specific Q? if/when you have a specific problem, sure; just write code for another's job?, "not so much"...

Jan 2019-3-16

编辑：Jan 2019-3-16

在 MATLAB Online 中打开

The clear all will impede the method of using a persistent variable. Because this brute clearing of everything has other severe disadvantages also, omitting it is a good idea in general.

Adding a set of folders automatically to Matlab's path can cause problems, when any of the included folders contain M-files:

addpath(genpath('C:\Users\User\Desktop\TEI'));

Do you do this only to access the images in these folders? Then leave the path untouched. You are using absolute file names already, so do not pollute the path without needs.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Jan 2019-3-16

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/450393-overwritting-problem-in-for-loop#answer_365716

编辑：Jan 2019-3-16

在 MATLAB Online 中打开

nExisting = numel(dir(fullfile(folder, 'Grain #*.jpg')));
for i = 1:k
  f = sprintf('Select a ROI and double click to crop #%d',i);
  uiwait(warndlg(f));
  [B, rect] = imcrop(A);
  baseFileName = sprintf('Grain #%d.jpg', i + nExisting);
  fullFileName = fullfile(folder, baseFileName);
  if exist(fullFileName, 'file')  % with 'file' !!!
      error('Collision with filename: %s', fullFileName);
  end
  imwrite(B, fullFileName);
end
f = 'FINISHED!!';  % without sprintf
uiwait(warndlg(f));

Or use https://www.mathworks.com/matlabcentral/fileexchange/47434-natural-order-filename-sort (link) tofind the largest index in the file names and start counting there. (I'd prefer this.)

Another idea is to check the existence of a file name dynamically:

count = 1;
for i = 1:k
  ...
  isFree = false;
  while ~isFree
    baseFileName = sprintf('Grain #%d.jpg', count);
    fullFileName = fullfile(folder, baseFileName);
    if ~exist(fullFileName, 'file')  % with 'file' !!!
       isFree = true;
    end
    count = count + 1;
  end
end

It is not tricky, as you can see.

2 个评论
显示无隐藏无

DIMITRIOS THEODOROPOULOS 2019-3-17

编辑：DIMITRIOS THEODOROPOULOS 2019-3-17

Thank you very much!!!!!I.Very clever!II couldnt not find how to count the existing files and the first command in the first solution was the answer!!

...Now i will try the others!