18 lines
537 B
Python
18 lines
537 B
Python
import cv2 as cv
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# read image
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img=cv.imread("opencv_logo.png",cv.IMREAD_UNCHANGED)
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# convert to rgba
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img_rgba=cv.cvtColor(img,cv.COLOR_BGR2BGRA)
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# split alpha channel
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blue,green,red,alpha = cv.split(img_rgba)
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#set alpha channel
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alpha[int(alpha.shape[0]/2):alpha.shape[0],int(alpha.shape[1]/2):alpha.shape[1]]=128
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# remix alpha to img_rgba
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img_rgba=cv.merge((blue,green,red,alpha))
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# show
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cv.imshow("changed",img_rgba)
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cv.waitKey(0)
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cv.destroyAllWindows()
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# compress and save
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cv.imwrite("img.png",img_rgba,[cv.IMWRITE_PNG_COMPRESSION,9]) |