Reader small image

You're reading from  Mastering OpenCV 4 with Python

Product typeBook
Published inMar 2019
Reading LevelExpert
PublisherPackt
ISBN-139781789344912
Edition1st Edition
Languages
Tools
Right arrow
Author (1)
Alberto Fernández Villán
Alberto Fernández Villán
author image
Alberto Fernández Villán

Alberto Fernndez Villn is a software engineer with more than 12 years of experience in developing innovative solutions. In the last couple of years, he has been working in various projects related to monitoring systems for industrial plants, applying both Internet of Things (IoT) and big data technologies. He has a Ph.D. in computer vision (2017), a deep learning certification (2018), and several publications in connection with computer vision and machine learning in journals such as Machine Vision and Applications, IEEE Transactions on Industrial Informatics, Sensors, IEEE Transactions on Industry Applications, IEEE Latin America Transactions, and more. As of 2013, he is a registered and active user (albertofernandez) on the Q&A OpenCV forum.
Read more about Alberto Fernández Villán

Right arrow

The coordinate system in OpenCV

To show you the coordinate system in OpenCV and how to access individual pixels, we are going to show you a low-resolution image of the OpenCV logo:

This logo has a dimension of 20 × 18 pixels, that is, this image has 360 pixels. So, we can add the pixel count in every axis, as shown in the following image:

Now, we are going to look at the indexing of the pixels in the form (x,y). Notice that pixels are zero-indexed, meaning that the upper left corner is at (0, 0), not (1, 1). Take a look at the following image, which indexes three individual pixels. As you can see, the upper left corner of the image is the coordinates of the origin. Moreover, y coordinates get larger as they go down:

The information for an individual pixel can be extracted from an image in the same way as an individual element of an array is referenced in Python. In the...

lock icon
The rest of the page is locked
Previous PageNext Page
You have been reading a chapter from
Mastering OpenCV 4 with Python
Published in: Mar 2019Publisher: PacktISBN-13: 9781789344912

Author (1)

author image
Alberto Fernández Villán

Alberto Fernndez Villn is a software engineer with more than 12 years of experience in developing innovative solutions. In the last couple of years, he has been working in various projects related to monitoring systems for industrial plants, applying both Internet of Things (IoT) and big data technologies. He has a Ph.D. in computer vision (2017), a deep learning certification (2018), and several publications in connection with computer vision and machine learning in journals such as Machine Vision and Applications, IEEE Transactions on Industrial Informatics, Sensors, IEEE Transactions on Industry Applications, IEEE Latin America Transactions, and more. As of 2013, he is a registered and active user (albertofernandez) on the Q&A OpenCV forum.
Read more about Alberto Fernández Villán