I/O and GUI

In this chapter, we will cover the following recipes:

• Reading images from file
• Simple image transformations—resizing and flipping
• Saving images using lossy and lossless compression
• Showing images in an OpenCV window
• Working with UI elements, such as buttons and trackbars, in an OpenCV window
• Drawing 2D primitives—markers, lines, ellipses, rectangles, and text
• Handling user input from a keyboard
• Making your app interactive through handling user input from a mouse
• Capturing and showing frames from a camera
• Playing frame stream from video
• Obtaining a frame stream properties
• Writing a frame stream into video
• Jumping between frames in video files