Search icon
Arrow left icon
All Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Newsletters
Free Learning
Arrow right icon
Mastering OpenCV 4 with Python

You're reading from  Mastering OpenCV 4 with Python

Product type Book
Published in Mar 2019
Publisher Packt
ISBN-13 9781789344912
Pages 532 pages
Edition 1st Edition
Languages
Author (1):
Alberto Fernández Villán Alberto Fernández Villán
Profile icon Alberto Fernández Villán

Table of Contents (20) Chapters

Preface Section 1: Introduction to OpenCV 4 and Python
Setting Up OpenCV Image Basics in OpenCV Handling Files and Images Constructing Basic Shapes in OpenCV Section 2: Image Processing in OpenCV
Image Processing Techniques Constructing and Building Histograms Thresholding Techniques Contour Detection, Filtering, and Drawing Augmented Reality Section 3: Machine Learning and Deep Learning in OpenCV
Machine Learning with OpenCV Face Detection, Tracking, and Recognition Introduction to Deep Learning Section 4: Mobile and Web Computer Vision
Mobile and Web Computer Vision with Python and OpenCV Assessments Other Books You May Enjoy

Advanced drawing

In this section, we are going to see how to combine some of the aforementioned functions to draw basic shapes in OpenCV (for example, lines, circles, rectangles, and text, among others) to render a more advanced drawing. To put all these pieces together, we have built an analog clock to show you the current time (hour, minutes, and seconds). For this, two scripts are coded:

  • analog_clock_values.py
  • analog_clock_opencv.py

The analog_clock_opencv.py script draws an analog clock, using cv.line(), cv.circle(), cv.rectangle(), and cv2.putText(). In this script, we first draw the static drawing. In this sense, you can see that there are two arrays containing fixed coordinates:

hours_orig = np.array(
[(620, 320), (580, 470), (470, 580), (320, 620), (170, 580), (60, 470), (20, 320), (60, 170), (169, 61), (319, 20),
(469, 60), (579, 169)])

hours_dest = np.array(
...
lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $15.99/month. Cancel anytime}