Andrea Pennisi, Phd

Contour Extracion is a common image processing technique aims at indentifying the structural outline of objects in image. A contour can help in indentifying a shape of object and for such a reason, they are widely use for segmentation, text recognition, shape recognition, etc. A contour is a curved line representing the boundary of the same values or the same intensities. Before going deeper into the contour world, we have to understand the difference between edges and contours.

Filtering is perhaps the most fundamental operation of image processing and computer vision. It is a fundamental step when you have to deal with tasks like: noise reduction, contour extraction, text recognition, etc. The main filters can be divided in two big categories: low-pass filters (LPF), which help in removing noise, blurring images, etc., and high-pass filters (HPF) that help in finding edges in images. In this post, we are going to talk about: Gaussian Filter, Median Filter, and Bilater Filter and we will see some code example as well as the results of each filter applied to our lena image.

OpenCV is the most popular library for computer vision and image processing. I started using it for my master (it was a beta version 0.98) thesis and I am stil using it. nitially, I did not understand why the images were loaded as BGR and not RGB. Then after having reading few articles, I came back with an answer. Basically, BGR was the common color format used among camera manufacturers and software providers (e.