Example python code for : Download s3 object as opencv image in memory and upload too

Just see the code
It's not difficult.

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import cv2

import numpy as np

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def lambda_handler(event, context):

# TODO implement

bucket_name = event['Records'][0]['s3']['bucket']['name']

s3_path = event['Records'][0]['s3']['object']['key']

#download object

obj = s3_client.get_object(Bucket=bucket_name, Key=s3_path)

#obj to cv2

nparr = np.frombuffer(obj['Body'].read(), np.uint8)

img = cv2.imdecode(nparr, cv2.IMREAD_COLOR)

#simple image processing

reimg = cv2.resize(img, (100,100) )

#cv2 to string

image_string = cv2.imencode('.png', reimg)[1].tostring()

#upload

s3_client.put_object(Bucket='thum-prj-output', Key = s3_path, Body=image_string)

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