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Picture shift

Convert the original image src to the target image dst by the conversion matrix M:

   dst(x, y) = src(M11x + M12y+M13, M21x+M22y+M23)

Moving the original image src 200 pixels to the right and 100 pixels to down, the corresponding relationship is:

   dst(x, y) = src(x+200, y+100)

Complete the above expression according to the formula, as shown below.

   dst(x, y) = src(1·x + 0·y + 200,  0·x + 1·y + 100)

According to the above expression, we can determine the value of each element in the corresponding conversion matrix M, as shown below.

M11=1

M12=0

M13=200

M21=0

M22=1

M23=100

Substituting the above values into the transformation matrix M, we can get,

M = []

Next, we directly use the conversion matrix M to call the function cv2.warpAffine () to complete the translation of the image.

Code:

 import cv2
import numpy as np
img = cv2.imread('yahboom.jpg',1)
#cv2.imshow('src',img)
imgInfo = img.shape
height = imgInfo[0]
width = imgInfo[1]
####
matShift = np.float32([[1,0,200],[0,1,100]])# 2*3
dst = cv2.warpAffine(img, matShift, (height, width))    #1 data 2 mat 3 info
# Shift matrix
# cv2.imshow('dst',dst)
# cv2.waitKey(0)

 After running the following program, two images will be displayed in the jupyterLab control interface, that is original image and the translated image.

#bgr 8 to jpeg format
import enum
import cv2
 
def bgr8_to_jpeg(value, quality=75):
    return bytes(cv2.imencode('.jpg', value)[1])

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 eachother
image_container = widgets.HBox([image_widget1, image_widget2])
 
# display the container in this cell's output
display(image_container)
#display(image_widget2)
 
img1 = cv2.imread('yahboom.jpg',1)
image_widget1.value = bgr8_to_jpeg(img1)
image_widget2.value = bgr8_to_jpeg(dst)

[Original picture]                                [Shift picture]

According to the above picture, this picture has moved to the lower right corner (200, 100).