def _initialise_stream(self, camera_config):
cam_number = camera_config.camera_number.value()
width = camera_config.width.value()
height = camera_config.height.value()
stream = CaptureManager(Camera(cam_number, width, height))
stream.create_capture()
return stream
def _test_camera(self):
# Check that values are integers
try:
camera = Camera(int(self.txt_number.text()),
int(self.txt_width.text()),
int(self.txt_height.text()))
except ValueError:
QMessageBox.critical(
self, "Camera Error",
"Camera number, width, and height must be integers")
return
# Check that we can connect to the camera
stream = CaptureManager(camera)
stream.create_capture()
# Display a preview feed from the camera
breaking_frame = False
while True:
# Capture the next frame from the camera
frame = stream.get_frame()
if frame is None:
QMessageBox.critical(self, "Camera Error",
"Cannot find specified camera")
return
if frame is None:
breaking_frame = True
break
elif cv2.waitKey(1) not in (255, -1):
break
small = cv2.resize(frame, (0, 0), fx=0.5, fy=0.5)
cv2.imshow('Camera Preview (Press any key to exit)', small)
# Check resolution is acceptable
set_width = int(stream.get_width())
set_height = int(stream.get_height())
if set_width != camera.get_camera_width(
) or set_height != camera.get_camera_height():
QMessageBox.warning(
self, "Camera Error",
"Could not set the camera to the specified resolution: {}x{}.\nThe camera defaulted "
"to {}x{}.".format(camera.get_camera_width(),
camera.get_camera_height(), set_width,
set_height))
self.txt_width.setText(str(set_width))
self.txt_height.setText(str(set_height))
return
stream.release_resources()
cv2.destroyAllWindows()
# Opening the camera controls window stops the camera from working; reopen this window
if breaking_frame:
self._test_camera()
def _test_camera_settings(self):
# Check that we can connect to the camera
stream = CaptureManager(self._camera_config)
stream.create_capture()
stream.read_frame()
read_ok = stream.is_read_ok()
stream.release_resources()
if not read_ok:
# Capture the next frame from the camera
raise ValueError
def _display_camera_preview(self):
stream = CaptureManager(self._camera_config)
stream.create_capture()
while True:
stream.read_frame()
if stream.is_read_ok():
res = stream.get_frame().get_frame()
if res is not None:
small = res
cv2.imshow('Camera Preview', small)
cv2.waitKey(50)
if cv2.getWindowProperty('Camera Preview',
cv2.WND_PROP_VISIBLE) == 0:
break
cv2.destroyAllWindows()
stream.release_resources()
class StreamManager:
def __init__(self, camera_config, cam_position):
self.camera_config = camera_config
self.camera_position = cam_position
self.stream = None
self._scanner = None
def initialise_stream(self, ):
self.stream = CaptureManager(self.camera_config)
def create_capture(self):
self.stream.create_capture()
def release_capture(self):
self.stream.release_resources()
def create_scanner(self,config):
if self.camera_position == CameraPosition.SIDE:
plate_type = "None"
barcode_sizes = DataMatrix.DEFAULT_SIDE_SIZES
else:
plate_type = config.plate_type.value()
barcode_sizes = [config.top_barcode_size.value()]
if plate_type == "None":
self._scanner = OpenScanner(barcode_sizes)
else:
self._scanner = GeometryScanner(plate_type, barcode_sizes)
def process_frame(self,frame):
if frame is None:
return ScanResult(0)
return self._scanner.scan_next_frame(frame)
def get_frame(self):
self.stream.read_frame()
if self.stream.is_read_ok():
frame = self.stream.get_frame()
return frame
return None
def _open_camera_controls(self):
camera_num = int(self.txt_number.text())
CaptureManager.open_camera_controls(camera_num)
def initialise_stream(self, ):
self.stream = CaptureManager(self.camera_config)