How to take BoundingBox of all objects as single object. Then want to crop region by using BoundingBox parameters.

Thanks

there is a simply way of scanning the image along the rows using bwlabel. The idea is to separate the characters along the rows and eliminate the line space amongst the rows and then take one row at the time. Of course, this only works when there is no connection between the text rows. Below is one example:

url = 'http://blogs.mathworks.com/images/steve/186/scanned_page.png';
bw = imread(url);
bw = ~bw(1107:1194, 17:135);
imshow(bw)
% Initialize
WP = 1:size(bw,1);
% Assign 0 to the lines between characters
% and 1 to the lines filled with characters
for i = 1:size(bw,1)
    l = length(find(bw(i,:) == 0));
    if (l == size(bw,2))
        WP(i) = 0;
    else
        WP(i) = 1;
    end
end
% Find and separate the image in row-character-blocks
startofblock = strfind(WP, [0,1]);
endofblock = strfind(WP,[1,0]);
statistics = [];
for i = 1:size(startofblock,2)
    subplot(5,2,i);
    imshow(bw(startofblock(i)+1:endofblock(i),:))
    stats = regionprops(bwlabel(bw(startofblock(i)+1:endofblock(i),:)),'Image');
    statistics = cat(1, statistics, stats);
end

The only problem is that we have 20 characters instead of 19. More precisely, two caracters (”a” and “r” are viewed as one connected character “ar” as they are actually connected. On the other hand there are 2 characters that are disconnected (see “f” and “a” from the last line). However, this is another story and you can use some other algorithms for segmentation and character connection before segmentation.

Best regards,

IB

I want making correspondance between regions labels in two images (images of the same building scene), so, initially, i segmented these images (according region segmentation technique), in order to labeling regions in each image i use regionprops.

my question is: which is the best criterions to order labeled objects?and how? knowing that this criterion must help me to doing correspondance between two images regions?

I chosed centroid criterion according:

[Ld,numd] = bwlabel(right_image);
[Lg,numg] = bwlabel(left_image);

cgd=regionprops(Ld,'Centroid');
figure(8),subplot(1,2,1),imshow(right_image)
hold on
for k = 1:numel(cgd)
    c = cgd(k).Centroid;
    text(c(1), c(2), sprintf('%d', k), ...
           'Color', 'b', ...
           'FontWeight', 'bold',...
        'HorizontalAlignment', 'center', ...
        'VerticalAlignment', 'middle');
end
hold off

cgg=regionprops(Lg,'Centroid');
figure(8),subplot(1,2,2),imshow(left_image)
hold on
for k = 1:numel(cgg)
    c = cgg(k).Centroid;
    text(c(1), c(2), sprintf('%d', k), ...
           'Color', 'b', ...
           'FontWeight', 'bold',...
        'HorizontalAlignment', 'center', ...
        'VerticalAlignment', 'middle');
end
hold off

But, i found it false way because same regions don’t have same centroids in two images.

can you help me please?

NB: I have matlab v.7.6(R 2008a).