Welcome to Raspberry Pi 4B repository

OpenCV image read and display

1) Reading of images:

img = cv2.imread('yahboom.jpg', 0)  The first parameter is the path of the image, and the second parameter is how to read the image.

cv2.IMREAD_UNCHANGED: Keep the original format, can be represented by parameter -1;

cv2.IMREAD_COLOR:  Reading pictures in grayscale, can be represented by parameter 0;

cv2.IMREAD_GRAYSCALE: Reading pictures in color mode, can be represented by 1, default value;

cv2.IMREAD_UNCHANGED: Read pictures and include its alpha channel,can be represented by 2.

2) Displaying of image:

Code:

#bgr8 to jpeg format
 
import enum
import cv2
 
def bgr8_to_jpeg(value, quality=75):
return bytes(cv2.imencode('.jpg', value)[1])

# The image component in jupyterLab shows the read image
 
import ipywidgets.widgets as widgets
image_widget = widgets.Image(format='jpg', width=800, height=800)
display(image_widget)
 
image_widget.value = bgr8_to_jpeg(img)