how to replace the name of image with a number?

hello, I have a dataset that contain 300 images. the name of image is :

    464_img_2,464_img_3,464_img_4,464_img_5
    .
    .
    .
    1017_img_2,1017_img_3,1017_img_4,1017_img_5

I want to replace the beginning of image name in the order of 1 to 300 as shown:

    1_img_2,1_img_3,1_img_4,1_img_5
    .
    .
    .
    300_img_2,300_img_3,300_img_4,300_img_5

please, help me, How can do it?

[Stephen23]

Is each line here one string, or multiple strings? Can you please upload your data for us to try out.

Answer 1

[Stephen23]

This converts the first digits into their relative indices, putting them into ascending order:

C = {'464_img_2','464_img_3','464_img_4','464_img_5','1017_img_2','1017_img_3','1017_img_4','1017_img_5'};
D = regexp(C,'\d+','match','once');
[~,~,X] = unique(str2double(D));
E = arrayfun(@num2str,X,'UniformOutput',false);
F = regexprep(C,strcat('^',D),E)

The input and output strings are:

>> C
C = 
    '464_img_2'    '464_img_3'    '464_img_4'    '464_img_5'    '1017_img_2'    '1017_img_3'    '1017_img_4'    '1017_img_5'
>> F
F = 
    '1_img_2'    '1_img_3'    '1_img_4'    '1_img_5'    '2_img_2'    '2_img_3'    '2_img_4'    '2_img_5'

[souha abdalah]

this not work, the database contain 300 images

[Stephen23]

Can you please explain exactly what "this not work" means. Have you tried the code? What did it do that you did not expect?

Perhaps I misunderstood the nature of your data. Please upload the exact array of names that you need to be converted. Currently your question does not adequately explain the format of this data.

[souha abdalah]

there is my data

[Stephen23]

Your data is not in a dataset as you state in your question, but appears to be the structure returned by the function dir. You only need to run this line first:

C = {baseFileNames.name};

and the rest of my code exactly as before:

D = regexp(C,'\d+','match','once');
[~,~,X] = unique(str2double(D));
E = arrayfun(@num2str,X,'UniformOutput',false);
F = regexprep(C,strcat('^',D),E)

Sort Order

The only remaining question is the order: the filenames that you supplied are not in numeric order. If you want those filenames numbered according to number order then use my code as above. If you want the same order as dir returned (which is not specified in the documentation), then use the 'stable' option in unique:

[~,~,X] = unique(str2double(D),'stable');

[souha abdalah]

I used a dataset that contain 1200 images but for simplycity,I upload the list of names because the dataset is very large. I tried to use this code, so good, these names are changed, but when I open the folder containing the dataset, the names are not changed. how can I save the result?

[Thorsten]

If you want to rename the file on disk, use movefile(oldfilename, newfilename).

[souha abdalah]

thanks