def ros2cv(msg, scale=1, offset=0):
if hasattr(msg, 'format'):
return compressed_imgmsg_to_cv2(msg)
if 'FC' in msg.encoding:
passimg = numpy.nan_to_num(imgmsg_to_cv2(msg))
valscaled = cv2.convertScaleAbs(passimg, None, scale, offset)
return valscaled
mono = msg.encoding.startswith('mono') or msg.encoding[-1] in [
'1', 'U', 'S', 'F'
]
return imgmsg_to_cv2(msg, 'mono8' if mono else 'bgr8')
def images(cam):
"""Extract images from input stream to jpg files.
Args:
cam: Input stream of raw rosbag messages.
Returns:
File instances for images of input stream.
"""
# Set output stream title and pull first message
yield marv.set_header(title=cam.topic)
# Fetch and process first 20 image messages
name_template = '%s-{}.jpg' % cam.topic.replace('/', ':')[1:]
while True:
idx, msg = yield marv.pull(cam, enumerate=True)
if msg is None or idx >= 20:
break
# Deserialize raw ros message
pytype = get_message_type(cam)
rosmsg = pytype()
rosmsg.deserialize(msg.data)
# Write image to jpeg and push it to output stream
img = imgmsg_to_cv2(rosmsg, 'rgb8')
name = name_template.format(idx)
imgfile = yield marv.make_file(name)
cv2.imwrite(imgfile.path, img)
yield marv.push(imgfile)
def image(cam):
"""Extract first image of input stream to jpg file.
Args:
cam: Input stream of raw rosbag messages.
Returns:
File instance for first image of input stream.
"""
# Set output stream title and pull first message
yield marv.set_header(title=cam.topic)
msg = yield marv.pull(cam)
if msg is None:
return
# Deserialize raw ros message
pytype = get_message_type(cam)
rosmsg = pytype()
rosmsg.deserialize(msg.data)
# Write image to jpeg and push it to output stream
name = f"{cam.topic.replace('/', ':')[1:]}.jpg"
imgfile = yield marv.make_file(name)
img = imgmsg_to_cv2(rosmsg, 'rgb8')
cv2.imwrite(imgfile.path, img, (cv2.IMWRITE_JPEG_QUALITY, 60))
yield marv.push(imgfile)
def imgsrc(stream):
"""Convert ROS sensor_msgs/Image stream into cv2 image stream."""
while True:
rosmsg = yield marv.pull(stream)
if rosmsg is None:
break
try:
img = imgmsg_to_cv2(rosmsg, 'bgr8')
except (ImageFormatError, ImageConversionError) as err:
log = yield marv.get_logger()
log.error('could not convert image from topic %s: %s ',
stream.topic, err)
raise marv.Abort()
yield marv.push(img)