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5. OpenCV pixel operations

5.1 Pixel operations

We can change the pixel color at any position to a new one. Here we first read the image and then assign an area to white.

5.2 Actual effect display

Code path:

/home/pi/project_demo/06.Open_source_cv_fundamentals_course/A.introduction/Introduction_to_OpenCV/05_OpenCV_Pixel_Ops.ipynb

​x
import cv2

img = cv2.imread('yahboom.jpg',1)
(b,g,r) = img[100,100]
print(b,g,r)# bgr
#10 100 --- 110 100
i=j=0
for j in range(1,500):
img[i,j] = (255,255,255)
for i in range(1,500):
img[i,j] = (255,255,255)

# cv2.imshow('image',img) # cv2.waitKey(0) #1000 ms ```` ````python #bgr8 to jpeg format import enum import cv2 def bgr8_to_jpeg(value, quality=75): return bytes(cv2.imencode('.jpg', value)[1]) ```` ````python import ipywidgets.widgets as widgets image_ widget1 = widgets.Image(format='jpg', ) image_widget2 = widgets.Image(format='jpg', ) # create a horizontal box container to place the image widget next to each other image_container = widgets.HBox([image_widget1, image_widget2]) # display the container in this cell's output
display(image_container)

img1 = cv2.imread('yahboom.jpg',1)

image_widget1.value = bgr8_to_jpeg(img1) #Original
image_widget2.value = bgr8_to_jpeg(img) #After pixel manipulation