You might want to adjust your edge detection parameters first to get a better image. Other than that you can use a for loop to find the closest point to each point and use linspace() to find a path between them, then burn those points into the image
For each dot pair you've identified:
distance = sqrt((x2-x1)^2+(y2-y1)^2)
spacing = 0.4; % pixels between dots (to make sure we don't skip any)
numPoints = distance/spacing;
xLine = linspace(x1, x2, numPoints);
yLine = linspace(y1, y2, numPoints);
rows = round(yLine);
columns = round(xLine);
for k = 1 : length(xLine)
edgeImage(rows(k), columns(k)) = true;
end
