How to draw a straight across the centroid points of the barcode using best fit points

This is the processed image and I can't increase the bwareaopen() as it won't work for my other image.

EDITED: Anyway I'm trying to find the shortest points in the centre points of the barcode, to get the straight line across the centre points in the barcode.

Example: After doing a centroid command, the points in the barcode are near to each other. Therefore, I just wanted to get the shortest points(which is the barcode) and draw a straight line across.

All the points need not be join, best fit points will do.

EDITED: Step 1

EDITED: Step 2

EDITED: Step 3

Answer 1

[Image Analyst]

Maybe run imclose and filter it to grab the largest blob, then find the largest inscribed rectangle with this:

http://www.mathworks.com/matlabcentral/fileexchange/28155-inscribedrectangle

I haven't tried it so I don't know if it can handle tilted rectangles.

Otherwise, just use the points Chandra finds and call improfile() to get a profile line across the bar code. Then scan the profile to find out where it starts and stops.

Answer 2

[Image Analyst]

Kim, because you have two "lines" I think you need to use RANSAC (<http://en.wikipedia.org/wiki/Ransac)>, unless you can filter out the numbers from your image somehow, in which case you can use polyfit.