Learning OpenCV 4 Computer Vision with Python 3 - Third Edition

Reading/writing an image file

OpenCV provides the imread function to load an image from a file and the imwrite function to write an image to a file. These functions support various file formats for still images (not videos). The supported formats vary—as formats can be added or removed in a custom build of OpenCV—but normally BMP, PNG, JPEG, and TIFF are among the supported formats.

Let's explore the anatomy of the representation of an image in OpenCV and NumPy. An image is a multidimensional array; it has columns and rows of pixels, and each pixel has a value. For different kinds of image data, the pixel value may be formatted in different ways. For example, we can create a 3x3 square black image from scratch by simply creating a 2D NumPy ...