Picamera capture and get single pixel r,g,b values

[tanapox]

Hi, first a disclaimer, i have almost zero knowledge in python, just getting code snippets all around an adding to my project..

My goal is it to use the Pi Camera to capture a screenshot and check the red, green and blue value of a specific pixel.

This is part of the code i used:

from picamera import PiCamera
from io import BytesIO
from PIL import Image

camera = PiCamera()
camera.resolution=(1280,720)

stream =BytesIO()

stream.seek(0)
camera.capture (stream,'jpeg')
im=Image.open (stream)

r,g,b=im.getpixel((x,y))

I'm using this in a Pi Zero W and is really slow.
I tried to skip the jpeg capture and go directly with the rgb format which , i think is the reason why this is so slow, using this system:

import picamera
import picamera.array

with picamera.PiCamera() as camera:
with picamera.array.PiRGBArray(camera) as output:
camera.capture(output, 'rgb')
print('Captured %dx%d image' % (
output.array.shape[1], output.array.shape[0]))

but i have no idea how to get the rgb values from output PiRGBArray

Thanks

Sorry for the bad english..

[blimpyway]

Please use code tags to format code.

for your problem, add the line:

Code: Select all

		print("pixel at 100x100", output.array[100,100])

with the same indentation as previouse print.

See the result is a 3 number tuple? these are the rgb values of pixel at line 101 column 101(*) in the captured image.

So the output array is three dimensional:
shape[0] = 480 (lines)
shape[1] = 720 (columns)
shape[2] = 3 (r,g,b values)

Code: Select all

   red_pixel_at_line_50_column_200 = output.array[49,199,0]
  

(*) an array's first index is 0

[tanapox]

Thank you for the answer