How can i extract all labeled objects in a image and save every object as an image?

I have labeled 650 images in Image labeler. Now i want to save every object i have labeled as a 81X81 pixel image.How can i do that?

Answer 1

[Daniel Vieira]

with the image labeler you made a table where the first column is the image file, and the others are each label, each cell containing the bounding boxes of each object. So:

% T -> your table
for k=1:height(T)
    I=imread(T.file{k}); % I don't quite remember it the variable is "file", change it to the name of your 1st variable
    for h=2:width(T)
        for z=1:size(T{k,h},1)
            subI=imresize(imcrop(I,)T{k,h}(z,:),[81 81]);
            writeimage(subI,"file "+k+" "+h+" "+z+".png") % change this string to something suitable to you
        end
    end
end

[Toni Vukasinovic]

Could you please specify what each variable is that i have to put in your code...this is what i have,plus the images in a seperate folder and a folder called PixelLabelData

[Toni Vukasinovic]

I have done the following as you segested.

for k=1:height(gTruth)
    I=imread(gTruth.LabelData{k}); % I don't quite remember it the variable is "file", change it to the name of your 1st variable
    for h=2:width(gTruth)
        for z=1:size(gTruth{k,h},1)
            subI=imresize(imcrop(I,),gTruth{k,h}(z,:),[81 81]);
            writeimage(subI,"file "+k+" "+h+" "+z+".png") % change this string to something suitable to you
        end
    end
end

But I get the following error

subI=imresize(imcrop(I,),gTruth{k,h}(z,:),[81 81]);
                                    ↑
Error: Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for
mismatched delimiters.

[Daniel Vieira]

gTruth here is not a table, it's a groundTruth object, that's why the code above doesn't work for you. You either need the Image Labeler App to export things in table format instead of gTruth (almost sure it does it), or you need to access the inner properties of gTruth, make a table, and work with it.