how to set the camera in raspberry pi to take black and white image?

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Are there any ways to set the camera in raspberry pi to take black and white image?, like using some commands / code in picamera library?

Since I need to compare the relative light intensity of a few different images, I'm worried that the camera will already so some adjustments itself when the object is under different illuminations, so even if I convert the image to black and white later on the object's 'true' black and white image will have been lost.

thanks

edit: basically what I need to do is to capture a few images of an object when the camera position is fixed, but the position of the light source is changed (and so the direction of illumination is changed as well). Then for each point on the image I will need to compare the relative light intensity of the different images. As long as the light intensity, or the 'brightness' of all the images are relative to the same scale, then it's ok, but I'm not sure if this is the case. I'm sure if the camera will adjust something like contrast automatically itself when an image is 'inherently' darker or brighter.

To get a black and white image (monochrome, grayscale), just configure your camera. Create a "takeashot.py" ( sudo nano takeashot.py ):

import picamera                  # import files

camera = picamera.PiCamera()     # initialize camera
camera.color_effects = (128,128) # turn camera to black and white
camera.capture('image1.jpg')     # take a shot

Execute: sudo python takeashot.py

That´s it

You can learn more at 10. API - picamera.camera Module

Under color_effects, you read "to make the image black and white set the value to (128, 128)."

Raspberry Pi Camera Module, to take a picture with the camera and save it directly as 2 bit black/white bitmap. Taking jamesh idea, I have put together a small c program: Now your Camera Module is connected and the software is enabled, try out the command line tools raspistill and raspivid. Open a terminal window by clicking the black monitor icon in the taskbar: Type in the following command to take a still picture and save it to the Desktop: raspistill -o Desktop/image.jpg. Press Enter to run the command.

What do you mean by "black and white image," in this case? There is no "true" black and white image of anything. You have sensors that have some frequency response to light, and those give you the values in the image.

In the case of the Raspberry Pi camera, and almost all standard cameras, there are red, green and blue sensors that have some response centered around their respective frequencies. Those sensors are laid out in a certain pattern, as well. If it's particularly important to you, there are cameras that only have an array of a single sensor type that is sensitive to a wider range of frequencies, but those are likely going to be considerable more expensive.

You can get raw image data from the raspi camera with picamera. This is not the "raw" format described in the documentation and controlled by format, which is really just the processed data before encoding. The bayer option will return the actual raw data. However, that means you'll have to deal with processing by yourself. Each pixel in that data will be from a different color sensor, for example, and will need to be adjusted based on the sensor response.

The easiest thing to do is to just use the camera normally, as you're not going to get great accuracy measuring light intensity in this way. In order to get accurate results, you'd need calibration, and you'd need to be specific about what the data is for, how everything is going to be illuminated, and what data you're actually interested in.

Take a picture as a 2 bit black/white bitmap, Ideally, the module would have a CS or C lens mount. Getting a B&W image is possible with a regular camera (with the IR filter) using response of these pixels and create a monochrome image from raw Bayer data. This document describes the use of the four Raspberry Pi camera applications, as of 30 April 2020. There are four applications provided: raspistill , raspivid , raspiyuv and raspividyuv . raspistill and raspiyuv are very similar and are intended for capturing images; raspivid and raspvidyuv are for capturing video.

v4l before python:
v4l2-ctl -c color_effects=1

From:

v4l2-ctl -L
User Controls
...
                 color_effects (menu)   : min=0 max=15 default=0 value=1
                            0: None
                            1: Black & White
                            2: Sepia
...

Nota: I've done this successfully, while my camera was running!

Does a monochrome camera module exist?, Is there a way to configure my Raspberry Pi 3 Model B's camera Or if you're wanting to process mono images, take the YUV frame and just  Set a low resolution, I think you can also set black and white (using color_effects, it may not be worth it). You may need to fix an exposure. You may need to fix an exposure. Capture an image to a RAM disk as suggested in another answer, using a fixed filename (i.e. don't delete, overwrite next time).

Grayscale Video, I transferred it to my RaspberryPi with RaspberryPi camera and got it working Oh, and then the coordinate creates a black spot on a white image as Possibly you don't have to override the output but can put it in stream or  THE OFFICIAL RASPBERRY PI CAMERA GUIDE Image height--height or -h Sets the height of the resulting image. Up to 1944 (Camera Module v1), 2464 (CM v2), or 3040 (HQ Camera) – the upper limit for video footage is 1080. Image rotation--rotation or -rot (0 to 359) Sets the rotation of the preview and saved image. Note that only 0, 90, 180, and 270

Quick image processing, The camera recently started producing all black images (.jpeg) captured to take the photo the video stream flashed black, the photo is captured, and then Did the original camera actually adjust exposure, gain, and white  Open up your Raspberry Pi Camera module. Be aware that the camera can be damaged by static electricity. Before removing the camera from its grey anti-static bag, make sure you have discharged yourself by touching an earthed object (e.g. a radiator or PC Chassis). Install the Raspberry Pi Camera module by inserting the cable into the Raspberry Pi.

Camera preview works, but capture produces an all , will there be an option to grayscale camera output? (setting UV which you can use to get B&W), imageFX (e.g. negative, posterise, denoise, I'd take it in colour and if I wanted a monochrome 'Arty' picture I'd feed it through  raspistill. raspistill is the command line tool for capturing still photographs with the camera module. Basic usage of raspistill. With the camera module connected and enabled, enter the following command in the Terminal to take a picture: raspistill -o cam.jpg. In this example the camera has been positioned upside-down.

Comments
  • The cells will be RGB. There are no black/white sensors.
  • edited the question. and also if I just convert the rgb image into black and white using the python libraries, how does it work basically?
  • To be precise, there are not actually different sensors for red, green and blue in the camera. It's a cmos sensor array in which all the sensors are identical. The color comes from a bayer pattern rgb filter, which allows only one color for each pixel.