pip install numpy

pip install matplotlib

pip install opencv-python

image.py

import cv2 as cv
import sys
 
#chama a funcao cv::imread e cria e armazena um objeto cv:Mat
img = cv.imread(cv.samples.findFile("starry_night.jpg"))
 
#verifica se a imagem foi carregada corretamente
if img is None:
   sys.exit("Could not read the image.")
 
#cria uma janela para mostrar a imagem - arg1 = nome da janela, arg2 = obj cv:Mat
cv.imshow("Display window", img)
 
#funcao cv:waitkey tempo de espera, entrada em milisegundos, '0' significa para sempre
k = cv.waitKey(0)
 
#pressiona 's' para salvar o arquivo
if k == ord("s"):
#funcao cv:imwrite salva o objeto cv:Mat como png
   cv.imwrite("starry_night.png", img)

Utilize a imagem abaixo para o teste:

Python: cv.imread( filename[, flags] ) → retva

Formatos suportados:

• Windows bitmaps - *.bmp, *.dib (always supported)
• JPEG files - *.jpeg, *.jpg, *.jpe (see the Note section)
• JPEG 2000 files - *.jp2 (see the Note section)
• Portable Network Graphics - *.png (see the Note section)
• WebP - *.webp (see the Note section)
• AVIF - *.avif (see the Note section)
• Portable image format - *.pbm, *.pgm, *.ppm *.pxm, *.pnm (always supported)
• PFM files - *.pfm (see the Note section)
• Sun rasters - *.sr, *.ras (always supported)
• TIFF files - *.tiff, *.tif (see the Note section)
• OpenEXR Image files - *.exr (see the Note section)
• Radiance HDR - *.hdr, *.pic (always supported)
• Raster and Vector geospatial data supported by GDAL (see the Note section)

• cv.IMREAD_UNCHANGED
• cv.IMREAD_GRAYSCALE
• cv.IMREAD_COLOR - PADRÂO
• cv.IMREAD_ANYDEPTH
• cv.IMREAD_ANYCOLOR
• cv.IMREAD_LOAD_GDAL
• cv.IMREAD_REDUCED_GRAYSCALE_2
• cv.IMREAD_REDUCED_COLOR_2
• cv.IMREAD_REDUCED_GRAYSCALE_4
• cv.IMREAD_IGNORE_ORIENTATION

Referências:

Install OpenCV-Python Windows

OpenCV-Python Tutorials

Started with Images