cv2imshow

cv2.imshow is a function in OpenCV’s Python bindings (highgui module) that displays an image in a window. It takes a window name and an image array as arguments and creates a window to render the image. The function itself does not manage window sizing or interaction beyond displaying the image; those traits are controlled through other highgui utilities such as namedWindow and destroyAllWindows.

The typical usage involves creating or loading an image, calling cv2.imshow with a chosen window title, and then processing GUI events with cv2.waitKey. The waitKey call is essential to keep the window responsive and to allow the window to render. Without waitKey, the window may appear and close immediately. To close the window, you can call cv2.destroyAllWindows or cv2.destroyWindow with the specific window name. The image passed to imshow should be a NumPy array, usually in BGR color order as produced by cv2.imread. If you have RGB data, convert it to BGR before displaying.

Notes and limitations: cv2.imshow requires a graphical user interface environment. It may not work on headless servers or in environments without a GUI backend. In such cases, display functions are not available. The function is cross-language in concept, with equivalent functionality in C++ as cv::imshow, while Python uses cv2.imshow.

Example (Python):

import cv2

img = cv2.imread('image.jpg')

cv2.imshow('Window', img)

cv2.waitKey(0)

cv2.destroyAllWindows()