read pixel color value camera V2

[julien.launay]

Hello,

I'm looking for API in python to read the color value of a pixel (x,y).
thanks to your help.

julien

[topguy]

Its the official Pi Camera you are taling about ?

http://picamera.readthedocs.io/en/relea ... pirgbarray

[julien.launay]

Hello,

How can I read pixel value at (x,y) with a black and white camera v2? not a rgb camera!
thanks to your help.

Julien

[julien.launay]

I see
15.1. PiArrayOutput
class picamera.array.PiArrayOutput(camera, size=None)[source]
Base class for capture arrays.

This class extends io.BytesIO with a numpy array which is intended to be filled when flush() is called (i.e. at the end of capture).

array
After flush() is called, this attribute contains the frame’s data as a multi-dimensional numpy array. This is typically organized with the dimensions (rows, columns, plane). Hence, an RGB image with dimensions x and y would produce an array with shape (y, x, 3).

But how can I use it using array to read the value of my black and white pixel at (x,y) position in the image?
do you have a example in python to read pixel value at x,y?
thanks to your help.

Julien

[DirkS]

How can I read pixel value at (x,y) with a black and white camera v2? not a rgb camera!

There is no black & white camera module.
And the NoIr camera is a normal colour cam with the IR filter removed

[julien.launay]

I am looking for a API to use my black and white camera V2

I only found the API in color RGB
with PiCamera() as camera:
camera.resolution = (64, 64)
with PiRGBArray

thanks

Julien

[DirkS]

I am looking for a API to use my black and white camera V2

See my reply above: a V2 (or any version) RPF black and white camera board does not exist...

[topguy]

http://picamera.readthedocs.io/en/relea ... piyuvarray
The Y in YUV means Luminanse value.

[julien.launay]

Hello,

I found.
with PiCamera() as camera:
camera.resolution = (64, 64)
with PiRGBArray(camera, size=(8, 8)) as stream:
camera.capture(stream, format='rgb', resize=(8, 8))
image = stream.array

juste use array and read pixel in the list, and it's working fine...

[julien.launay]

Hello,

All is working well.
But when I want to capture 640x480 it takes 20s! why is it so long?
is there a way to go faster?
thanks

Julien

[julien.launay]

Hello,

It's not the capture who takes time, but setting pixels on a canvas with tkinter! I use canvas.create_rectangle(). because I don't know how to set on pixel!

julien