openflexure-microscope-server/openflexure_microscope/camera/pi.py
2018-11-07 14:22:42 +00:00

486 lines
16 KiB
Python

# -*- coding: utf-8 -*-
"""
Raspberry Pi camera implementation of the StreamingCamera class.
NOTES:
Still port used for image capture
Preview port reserved for onboard GPU preview
Video port:
Splitter port 0: Image capture (if use_video_port == True)
Splitter port 1: Streaming frames
Splitter port 2: Video capture
Splitter port 3: [Currently unused]
StreamingCamera streams at video_resolution
Camera capture resolution set to video_resolution in frames()
Video port uses that resolution for everything. If a different resolution
is specified for video capture, this is handled by the resizer.
Still capture (if use_video_port == False) uses pause_stream_for_capture
to temporarily increase the capture resolution.
"""
from __future__ import division
import io
import time
import datetime
import sys
import os
import yaml
import copy
import numpy as np
from PIL import Image
import logging
# Pi camera
import picamera
import picamera.array
# Type hinting
from typing import Tuple
# Threading
import threading
from .base import BaseCamera, StreamObject
# Richard's fix gain
from .set_picamera_gain import set_analog_gain, set_digital_gain
# Manage config
from .config import load_config
HERE = os.path.abspath(os.path.dirname(__file__))
DEFAULT_CONFIG = os.path.join(HERE, 'config_picamera.yaml')
class StreamingCamera(BaseCamera):
def __init__(self):
"""Raspberry Pi camera implementation of StreamingCamera."""
# Run BaseCamera init
BaseCamera.__init__(self)
# Attach to Pi camera
self.camera = picamera.PiCamera()
# Camera settings
self.settings.update({
'video_resolution': (832, 624),
'image_resolution': (2592, 1944),
'numpy_resolution': (1312, 976),
'jpeg_quality': 75,
})
# Store state of StreamingCamera
self.state.update({
'stream_active': False,
'record_active': False,
'preview_active': False,
})
self.start_worker()
def initialisation(self):
"""Run any initialisation code when the frame iterator starts."""
pass
def close(self):
"""Close the Raspberry Pi StreamingCamera."""
# Run BaseCamera close method
BaseCamera.close(self)
# Detatch Pi camera
if self.camera:
self.camera.close()
# HANDLE SETTINGS
# TODO: Handle exceptions
# TODO: Have this take a dictionary (not a config file)
# TODO: Web API entry point to send settings as JSON to this method
# TODO: Separate method to store current settings back to YAML file
# TODO: API entry point to get settings to JSON
def update_settings(self, config_path: str=None) -> None:
"""Open config_picamera.yaml file and write to camera."""
global DEFAULT_CONFIG
paused_stream = False
if not self.state['record_active']: # If not recording a video
if self.state['stream_active']: # If stream is active
logging.info("Pausing stream to update settings.")
self.pause_stream_for_capture() # Pause stream
paused_stream = True # Remember to unpause stream when done
if not config_path:
config = load_config(DEFAULT_CONFIG)
else:
config = load_config(config_path)
logging.debug(config)
# StreamingCamera settings
if 'video_resolution' in config:
self.settings['video_resolution'] = config['video_resolution']
if 'image_resolution' in config:
self.settings['image_resolution'] = config['image_resolution']
if 'numpy_resolution' in config:
self.settings['numpy_resolution'] = config['numpy_resolution']
if 'jpeg_quality' in config:
self.settings['jpeg_quality'] = config['jpeg_quality']
if 'framerate' in config:
self.settings['framerate'] = config['framerate']
# Camera AWB
if 'awb_mode' in config:
self.camera.awb_mode = config['awb_mode']
if 'red_gain' in config and 'blue_gain' in config:
self.camera.awb_gains = (
config['red_gain'],
config['blue_gain'])
# Camera framerate
if 'framerate' in config:
self.camera.framerate = config['framerate']
# Camera exposure
if 'shutter_speed' in config:
self.camera.shutter_speed = config['shutter_speed']
if 'saturation' in config:
self.camera.saturation = config['saturation']
# Camera misc.
self.camera.led = False
# Richard's library to set analog and digital gains
if 'analog_gain' in config:
set_analog_gain(self.camera, config['analog_gain'])
if 'digital_gain' in config:
set_digital_gain(self.camera, config['digital_gain'])
if paused_stream: # If stream was paused to update settings
logging.info("Resuming stream.")
self.resume_stream_for_capture()
else:
raise Exception(
"Cannot update camera settings while recording is active.")
def change_zoom(self, zoom_value: int=1) -> None:
"""Change the camera zoom, handling recentering and scaling."""
zoom_value = float(zoom_value)
if zoom_value < 1:
zoom_value = 1
# Richard's code for zooming !
fov = self.camera.zoom
centre = np.array([fov[0] + fov[2]/2.0, fov[1] + fov[3]/2.0])
size = 1.0/zoom_value
# If the new zoom value would be invalid, move the centre to
# keep it within the camera's sensor (this is only relevant
# when zooming out, if the FoV is not centred on (0.5, 0.5)
for i in range(2):
if np.abs(centre[i] - 0.5) + size/2 > 0.5:
centre[i] = 0.5 + (1.0 - size)/2 * np.sign(centre[i]-0.5)
print("setting zoom, centre {}, size {}".format(centre, size))
new_fov = (centre[0] - size/2, centre[1] - size/2, size, size)
self.camera.zoom = new_fov
# LAUNCH ACTIONS
def start_preview(self) -> bool:
"""Start the onboard GPU camera preview."""
self.camera.start_preview()
self.state['preview_active'] = True
return True
def stop_preview(self) -> bool:
"""Stop the onboard GPU camera preview."""
self.camera.stop_preview()
self.state['preview_active'] = False
return True
def start_recording(
self,
target=None,
write_to_file: bool=True,
filename: str=None,
folder: str='record',
fmt: str='h264',
quality: int=15):
"""Start a new video recording, writing to a target object.
target (str/BytesIO): Target object to write bytes to.
(default StreamObject)
write_to_file (bool/NoneType): Should the StreamObject write to a file?
(default True for video capture)
filename (str): Name of the stored file.
(defaults to timestamp)
folder (str): Relative directory to store data file in.
fmt (str): Format of the capture.
(default 'h264')
"""
# Start recording method only if a current recording is not running
if not self.state['record_active']:
# If no target is specified, store to StreamingCamera
if not target:
# Create a new video and add to the video list
target_obj = self.new_video(StreamObject(
write_to_file=write_to_file,
filename=filename,
folder=folder,
fmt=fmt))
# Lock the StreamObject while recording
target_obj.lock()
# Store to the StreamObject target
target = target_obj.target
else:
target_obj = target
# Start the camera video recording on port 2
logging.info("Recording to {}".format(target))
self.camera.start_recording(
target,
format=fmt,
splitter_port=2,
resize=self.settings['video_resolution'],
quality=quality)
# Update state dictionary
self.state['record_active'] = True
return target_obj
else:
print(
"Cannot start a new recording\
until the current recording has stopped.")
return None
def stop_recording(self) -> bool:
"""Stop the last started video recording on splitter port 2."""
# Stop the camera video recording on port 2
logging.info("Stopping recording")
self.camera.stop_recording(splitter_port=2)
logging.info("Recording stopped")
# Update state dictionary
self.state['record_active'] = False
def pause_stream_for_capture(
self,
splitter_port: int=1,
resolution: Tuple[int, int]=None) -> None:
"""
Pause capture on a splitter port.
splitter_port (int): Splitter port to stop recording on
resolution ((int, int)): Resolution to set the camera to,
after stopping recording.
"""
logging.debug("Pausing stream")
# If no resolution is specified, default to image_resolution
if not resolution:
resolution = self.settings['image_resolution']
# Stop the camera video recording on port 1
self.camera.stop_recording(splitter_port=splitter_port)
# Increase the resolution for taking an image
self.camera.resolution = resolution
def resume_stream_for_capture(
self,
splitter_port: int=1,
resolution: Tuple[int, int]=None) -> None:
"""
Resume capture on a splitter port.
splitter_port (int): Splitter port to start recording on
resolution ((int, int)): Resolution to set the camera to,
before starting recording.
"""
logging.debug("Unpausing stream")
if not resolution:
resolution = self.settings['video_resolution']
# Reduce the resolution for video streaming
self.camera.resolution = resolution
# Resume the video channel
self.camera.start_recording(
self.stream,
format='mjpeg',
quality=self.settings['jpeg_quality'],
splitter_port=splitter_port)
def capture(
self,
target=None,
write_to_file: bool=False,
use_video_port: bool=False,
filename: str=None,
folder: str='capture',
fmt: str='jpeg',
resize: Tuple[int, int]=None):
"""
Capture a still image to a StreamObject.
Defaults to JPEG format.
Target object can be overridden for development purposes.
target (str/BytesIO): Target object to write data bytes to.
write_to_file (bool): Should the StreamObject write to a file,
instead of BytesIO stream?
use_video_port (bool): Capture from the video port used for streaming.
(lower resolution, faster)
filename (str): Name of the stored file.
(defaults to timestamp)
folder (str): Relative directory to store data file in.
fmt (str): Format of the capture.
(default 'h264')
resize ((int, int)): Resize the captured image.
"""
# If no target is specified, store to StreamingCamera
if not target:
# Create a new image and add to the image list
target_obj = self.new_image(StreamObject(
write_to_file=write_to_file,
filename=filename,
folder=folder,
fmt=fmt))
target = target_obj.target # Store to the StreamObject BytesIO
else:
target_obj = target
logging.info("Capturing to {}".format(target))
if not use_video_port:
# Pause video splitter port 1
self.pause_stream_for_capture()
self.camera.capture(
target,
format=fmt,
quality=100,
resize=resize,
bayer=True)
# Resume video splitter port 1
self.resume_stream_for_capture()
else:
self.camera.capture(
target,
format=fmt,
quality=100,
resize=resize,
bayer=False,
use_video_port=True)
# Update state dictionary
self.state['image_recent'] = str(target_obj)
return target_obj
def array(
self,
rgb=False,
use_video_port: bool=True,
resize: Tuple[int, int]=None) -> np.ndarray:
"""Capture an uncompressed still YUV image to a Numpy array.
use_video_port (bool): Capture from the video port used for streaming.
(lower resolution, faster)
resize ((int, int)): Resize the captured image.
"""
if use_video_port:
resolution = self.settings['video_resolution']
else:
resolution = self.settings['numpy_resolution']
if resize:
size = resize
else:
size = resolution
if not use_video_port:
self.pause_stream_for_capture(resolution=resolution)
logging.debug("Creating PiYUVArray")
with picamera.array.PiYUVArray(self.camera, size=size) as output:
logging.info("Capturing to {}".format(output))
self.camera.capture(
output,
resize=size,
format='yuv',
use_video_port=use_video_port)
if not use_video_port:
self.resume_stream_for_capture()
if rgb:
logging.debug("Converting to RGB")
return output.rgb_array
else:
return output.array
# HANDLE STREAM FRAMES
def frames(self):
"""
Create generator that returns frames from the camera.
Records video from port 1 to a byte stream,
and iterates sequential frames.
"""
# Run this initialisation method
self.initialisation()
self.wait_for_camera()
# Settings config
self.update_settings()
# Set stream resolution
self.camera.resolution = self.settings['video_resolution']
# Create stream
self.stream = io.BytesIO()
# Start recording on video splitter port 1
self.camera.start_recording(
self.stream,
format='mjpeg',
quality=self.settings['jpeg_quality'],
splitter_port=1)
# Update state
logging.debug("STREAM ACTIVE")
self.state['stream_active'] = True
# While the iterator is not closed
try:
while True:
# reset stream for next frame
self.stream.seek(0)
self.stream.truncate()
# to stream, read the new frame
time.sleep(1/self.settings['framerate']*0.1)
# yield the result to be read
frame = self.stream.getvalue()
# ensure the size of package is right
if len(frame) == 0:
pass
else:
yield frame
# When GeneratorExit or StopIteration raised, run cleanup code
finally:
logging.debug("Stopping stream recording on port 1")
self.camera.stop_recording(splitter_port=1)
self.state['stream_active'] = False
logging.debug("FRAME ITERATOR END")