MATLAB: Merge binary regions to get a bigger object

Question

when i do segmentation i get bboxes such as

bboxes =
            85          76          75          79
            90          79          55          78
            57         168          48          19
            91          92          38          67

how can i merge all the regions of the bounding box to one single object…. i want all the regions in one bounding box….

Answer 1

Try this

bboxes = [...
            85          76          75          79
            90          79          55          78
            57         168          48          19
            91          92          38          67]
allx1 = bboxes(:, 1)
ally1 = bboxes(:, 2)
allx2 = allx1 + bboxes(:, 3)
ally2 = ally1 + bboxes(:, 4)
maxWidth = max(allx2) - min(allx1)
maxHeight = max(ally2) - min(ally1)
overallBBox = [min(allx1), min(ally1), maxWidth, maxHeight]
% Display every individual box.
for k = 1 : size(bboxes, 1)
  rectangle('Position', bboxes(k, :), 'EdgeColor', 'k', 'LineWidth', 5);
  hold on;
end
% Display the overall box.
rectangle('Position', overallBBox, 'EdgeColor', 'r', 'LineWidth', 3);