imageZMQ test program to check jpg_buffer type, size and dimensions

test_create_image_jpg_buffer.py

"""test sending a jpg buffer and check type & size of buffer

A simple test program that creates an image, then converts it to a
jpg_buffer and checks the type(), ndim, size and shape of the jpg_buffer.

This program tests some imports and some OpenCV functions, as well.

Open Source Licensed under MIT License (MIT)
Copyright (c) 2020, Jeff Bass, jeff@yin-yang-ranch.com
"""

import sys
import time
import numpy as np
import cv2
import imagezmq

# Create a sender instance

sender = imagezmq.ImageSender()

# Create a simple image
image = np.zeros((400, 400, 3), dtype='uint8')
green = (0, 255, 0)
cv2.rectangle(image, (50, 50), (300, 300), green, 5)

rpi_name = 'test_name'  # need a sending text
jpeg_quality = 95  # 0 to 100, higher is better quality, 95 is cv2 default
ret_code, jpg_buffer = cv2.imencode(
    ".jpg", image, [int(cv2.IMWRITE_JPEG_QUALITY), jpeg_quality])
print('type of jpg_buffer', type(jpg_buffer))
print('ndim of jpg_buffer', jpg_buffer.ndim)
print('size of jpg_buffer', jpg_buffer.size)
print('shape of jpg_buffer', jpg_buffer.shape)

# any encryption function would go here
# encrypted_buffer = encryption_function(jpg_buffer)  # an example
# it should return <class 'numpy.ndarray'> type, as cv2.imencode does

# not sending for now; but this works in my other tests
# sender.send_jpg(rpi_name, encrypted_buffer)

Let me know if you try this and it runs OK. And if you have any questions, of course!