Welcome to DOFBOT-Ultra repository

Image Reading and Display

1. Image Reading:

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

cv2.IMREAD_UNCHANGED: Keep the original format unchanged, -1;

cv2.IMREAD_GRAYSCALE: Read the image in grayscale mode, can be represented by 0;

cv2.IMREAD_COLOR: Read a color image, can be represented by 1; default value

cv2.IMREAD_UNCHANGED: Read an image including its alpha channel, can be represented by 2.

2. Image Display

cv.imshow('frame', frame): Opens a window named 'frame' and displays the frame data (image/video data)

Parameter meanings:

The first parameter specifies the name of the window to be created and opened

The second parameter specifies the image to be displayed

2.1. Code and Actual Effect Display

Code path:

~/dofbot_opencv/scripts/1.OpenCV_basic/01_read_pic.ipynb

Main code:

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import cv2
img = cv2.imread('yahboom.jpg', 1)
# cv2.imshow('image', img)  # This line can only be executed from a py file in command line, it will pop up a video window
# cv2.waitKey (0)

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

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# Display the read image using image widgets in JupyterLab
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)

After running the code block, you can see the interface below showing the image has been read.