Starting with OpenCV on i.MX 6 processors
Introduction As the saying goes, a picture is worth a thousand words. It is indeed true to some extent: a picture can hold information about objects, environment, text, people, age and situations, among other information. It can also be extended to video, that can be interpreted as a series of pictures and thus holds motion information. This might be a good hint as to why computer vision (CV) has been a field of study that is expanding its boundaries every day. But then we come to the question: what is computer vision? It is the ability to extract meaning from an image, or a series of images. It is not to be confused with digital imaging neither image processing, which are the production of an input image and the application of mathematical operations to images, respectively. Indeed, they are both required to make CV possible. But what might be somehow trivial to human beings, such as reading or recognizing people, is not always true when talking about computers interpreting images. Although nowadays there are many well known applications such as face detection in digital cameras and even face recognition in some systems, or optical character recognition (OCR) for book scanners and license plate reading in traffic monitoring systems, these are fields that nearly didn't exist 15 years ago in people's daily lives. Self-driving cars going from controlled environments to the streets are a good measure of how cutting-edge this technology is, and one of the enablers of CV is the advancement of computing power in smaller packages. Being so, this blog post is an introduction to the use of computer vision in embedded systems, by employing the OpenCV 2.4 and 3.1 versions in Computer on Modules (CoMs) equipped with NXP i.MX 6 processors. The CoMs chosen were the Colibri and Apalis families from Toradex. OpenCV stands for Open Source Computer Vision Library, which is a set of libraries that contain several hundreds of computer vision related algorithms. It has a modular structure, divided in a core library and several others such as image processing module, video analysis module and user interface capabilities module, among others.