Camera - Expert Level Instructions

[mlivai]

(1 hr) Prepare detailed instructions showing how the part works and what is can do, at an expert level. (Include photos/screenshots).

[mlivai]

IMAGE 1:

[Reference: https://www.raspberrypi.com/documentation/accessories/camera.html]

[mlivai]

The camera can be controlled through the command line and through python code on the Raspberry Pi.

Command Line:

• raspistill command line tool to take a still image raspistill -o Desktop/image.jpg
• the -w -h tools allow you to change the width and height of the still image (resolution) raspistill -o Desktop/image-small.jpg -w 640 -h 480 -raspivid command line tool to record a video raspivid -o Desktop/video.h264

Python Code:

• You import the picamera library and create a picamera object with which you can capture images and record videos. from picamera import PiCamera camera = PiCamera() (Look at Additional Comments Under This Issue For Further Info)

[Reference: https://projects.raspberrypi.org/en/projects/getting-started-with-picamera/3 ]

[mlivai]

The resolution of the sensor is the number of pixels across the height and the number of pixels across width of the view of the camera.

• The max resolution for taking a still image is: 2592×1944.
• The max resolution for recording a video is: 1920×1080.
• The min resolution is: 64 x 64.
• The resolution can be adjusted in the code with: camera.resolution = (2592, 1944)

The frame rate of a camera is the number of frames recorded per second (fps).

• The framerate needs to be adjusted to 15 to enable maximum resolution.
• The framerate can be adjusted in the code with: camera.framerate = 15

[Reference: https://projects.raspberrypi.org/en/projects/getting-started-with-picamera/7 ]

[mlivai]

The camera is capable of rotating:

• The camera can be set to 0 (which resets it), 90, 180, and 270 degrees.
• The following code rotates the camera 180 degrees: camera.rotation = 180

[Reference: https://projects.raspberrypi.org/en/projects/getting-started-with-picamera/4 ]

[mlivai]

The images can be captured to a:

Capture to a file (start a preview and capture image to a file): camera.start_preview() camera.capture('foo.jpg') #one image

Capture to continuous images with loop:

for filename in camera.capture_continuous('img{counter:03d}.jpg'):
    sleep(300) # time to wait between each capture in seconds 

Resize a file to a size different than that of the resolution: camera.capture('filename.jpg', resize=(320, 240))

Capture Consistent Images (Make sure each image is consistent): Sensitivity: camera.iso = #100/200 for brighter conditions and 400/800 for darker conditions Exposure time (Amount of time it takes for camera to capture image): camera.shutter_speed = camera.exposure_speed Exposure gains: Allow time for analog_gainsand digital_gains to get to a value and then set camera.exposure_mode = #(off, auto, night, nightpreview, backlight, etc) [https://projects.raspberrypi.org/en/projects/getting-started-with-picamera/7] White Balance (Color Balance): camera.awb_mode = #(off, auto, sunlight, cloudy, shade, etc.) [https://projects.raspberrypi.org/en/projects/getting-started-with-picamera/7], capture camera.awb_gains into a variable and then set it equal to that variable after awb_mode is set Capture a sequence of images with loop:camera.capture_sequence(['image%02d.jpg' % i for i in range(10)])

Capture Image in Low Light: Set slow framerate Set shutter speed to max (6s) Set sensitivity (iso) according to lowlight (800) Set exposure mode to 'off' Capture image

Additional Functions with Images Include:

• capture to a stream (PIL image, network stream)
• overlaying images on the preview
• overlaying text on the output

[Reference: https://picamera.readthedocs.io/en/release-1.13/recipes1.html#capturing-resized-images ]

[mlivai]

• The camera requires 250 mA current.
• When the Pi and camera are functioning, there is a minimum of 1A required from the power supply not including additional peripherals.
• If the Pi is running on batteries, the picamera object needs to be closed (for example with camera.close())or destroyed. This is because when the picamera object is created, the camera itself is already running and this method would allow you to conserve battery life. However, this method of conserving battery life does not allow for the capturing continuous pictures (for example with camera.capture_continuous())

[Reference: https://picamera.readthedocs.io/en/release-1.13/faq.html ]

[mlivai]

The videos can be captured to a:

File:

camera.start_recording('filename.h264') 
camera.wait_recording(60) #records for a specified number of seconds
camera.stop_recording()

Multiple Files:

camera.start_recording('1.h264')
camera.wait_recording(5)
for i in range(2, 11):
    camera.split_recording('%d.h264' % i)
    camera.wait_recording(5)
camera.stop_recording()

Additional Functions With Videos Include:

• record to a stream (circular stream, network stream)

[Reference: https://picamera.readthedocs.io/en/release-1.13/recipes1.html#recording-video-to-a-file ]

[mlivai]

The LED can also be controlled by setting it to FALSE to turn it off and TRUE to keep it on. The following is an example of this: camera.led = False

[Reference: https://picamera.readthedocs.io/en/release-1.13/recipes1.html#controlling-the-led]

[ajb974]

Looks good.