Use of a particular file from bunch of files

I want to use a particular file from a bunch of files. So far I have used the following steps,

1) read and convert the image to binary

2) labeling the image using bwlabel()

3) used regionprops with BoundingBox attribute.

4) write each components to a new file based upon BoundingBox.

Now I have 11 files but I only need the file that has the face portion so that I can detect the edge of the particular file. How do I do that?

Answer 1

[Image Analyst]

If you did the conversion to binary correctly, the binary image would identify only the faces and so you'd have an image with just face. Maybe do color classification, or use the Computer Vision System Toolbox which identifies faces.

[Sayak]

My code so far::

function [s,j]= ext_imgg( input_args )

imagen=imread(input_args);

if size(imagen,3)==3 % RGB image

    imagen=rgb2gray(imagen);

end

%% Convert to inverted binary image

threshold = graythresh(imagen);

imagen =~im2bw(imagen,threshold);

%imagen=imagen > 25;

%% Remove all object containing fewer than 150 pixels

imagen = bwareaopen(imagen,150);

pause(1)

%% labeling components

[L Ne]=bwlabel(imagen);

propied=regionprops(L,'BoundingBox');

figure

imshow(~imagen);

title('Input Image with objects Marked')

hold on

%% using bounding box

for n=1:size(propied,1)

rectangle('Position',propied(n).BoundingBox,'EdgeColor','g','LineWidth',2)

end

hold off

pause (1)

j=0;

s=char();

for n=1:Ne

    [r,c] = find(L==n);

    n1=imagen(min(r):max(r),min(c):max(c));

    %figure,imshow(~n1);

    s1='im';

    s2=num2str(j);

    s3='.jpg';

    str=strcat(s1,s2,s3);

    s=char(s,str);

    imwrite(~n1,str,'jpg');

    pause(0.5)

    j=j+1;

end

end

By doing this I am getting the face in one of the files (though in binary format). Now how am I supposed to work on that particular file, discarding others? And should I make any changes to the code so that the efficiency gets better?

[Image Analyst]

I don't understand why you can't just work on it. Who's forcing you to work on any other files once you've found the one you want? What does "discard" mean - delete from disk? Or ignore? Once you've found the file you want, just work on it. Don't read in anymore images. It seems rather obvious.

[Sayak]

Actually by doing this I am getting more than one files (perfectly 11) where one of them contains the face. Now I am programmatically unable to find the one with the face.

Actual Image:: http://s13.postimage.org/o9z8e6ecn/image.jpg

Image with BoundingBox :: http://s7.postimage.org/8tth9pcbf/box.jpg

Look one of the box contains the face only, I want to use only that part of the image. Thats the problem.How to work on the image file that contains the face only?

[Image Analyst]

You're using a poor method to begin with. Why don't you use an established method like the Viola Jones method?

[Sayak]

Thanks for the guidance. I did not know about the method but it helped me a lot. Now under the same context I have another query [How to use a particular file from bunch of files ?]

I have a folder with many files. Some of the file contains the name human1.jpg, human2.jpg human3.jpg and so on. Now I want to work with those file only whose file name has a string 'human'. How do I do that? Any help is appreciated.

[Image Analyst]

See the FAQ: http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F You can specify the file pattern when you call dir:

filePattern = fullfile(folder, 'human*.jpg');
fileNames = dir(filePattern);

[Sayak]

ooh. Simple use of wildcard. How did I miss that? Anyways, thanks for the answer and that awesome link.