def cv_to_imgmsg(self, cvim, encoding="passthrough"):
"""
Convert an OpenCV :ctype:`CvArr` type (that is, an :ctype:`IplImage` or :ctype:`CvMat`) to a ROS sensor_msgs::Image message.
:param cvim: An OpenCV :ctype:`IplImage` or :ctype:`CvMat`
:param encoding: The encoding of the image data, one of the following strings:
* ``"passthrough"``
* one of the standard strings in sensor_msgs/image_encodings.h
:rtype: A sensor_msgs.msg.Image message
:raises CvBridgeError: when the ``cvim`` has a type that is incompatible with ``encoding``
If encoding is ``"passthrough"``, then the message has the same encoding as the image's OpenCV type.
Otherwise desired_encoding must be one of the standard image encodings
This function returns a sensor_msgs::Image message on success, or raises :exc:`opencv_latest.cv_bridge.CvBridgeError` on failure.
"""
img_msg = sensor_msgs.msg.Image()
(img_msg.width, img_msg.height) = cv.GetSize(cvim)
if encoding == "passthrough":
img_msg.encoding = self.cvtype_names[cv.GetElemType(cvim)]
else:
img_msg.encoding = encoding
# Verify that the supplied encoding is compatible with the type of the OpenCV image
if self.encoding_as_cvtype(encoding) != cv.GetElemType(cvim):
raise CvBridgeError, "encoding specified as %s, but image has incompatible type %s" % (
encoding, self.cvtype_names[cv.GetElemType(cvim)])
img_msg.step = img_msg.width * cv.CV_MAT_CN(cv.GetElemType(cvim))
img_msg.data = cvim.tostring()
return img_msg
def encoding_as_fmt(self, encoding):
source_channels = cv.CV_MAT_CN(self.encoding_as_cvtype(encoding))
if source_channels == 1:
fmt = "GRAY"
elif "rgb8" == encoding:
fmt = "RGB"
elif "rgba8" == encoding:
fmt = "RGBA"
elif source_channels == 3:
fmt = "BGR"
elif source_channels == 4:
fmt = "BGRA"
return fmt
def cv_to_imgmsg(self, cvim, encoding = "passthrough"):
"""
Convert an OpenCV CvArr type (that is, an IplImage or CvMat) to a ROS sensor_msgs Image message.
If encoding is "passthrough", then the message has the same encoding as the image's OpenCV type.
Otherwise encoding must be one of the defined strings "rgb8", "bgr8", "rgba8", "bgra8", "mono8" or "mono16".
In this case, the image must have the appropriate type:
CV_8UC3 (for "rgb8", "bgr8"),
CV_8UC4 (for "rgba8", "bgra8"),
CV_8UC1 (for "mono8"), or
CV_16UC1 (for "mono16").
"""
img_msg = sensor_msgs.msg.Image()
(img_msg.width, img_msg.height) = cv.GetSize(cvim)
if encoding == "passthrough":
img_msg.encoding = self.cvtype_names[cv.GetElemType(cvim)]
else:
img_msg.encoding = encoding
# Verify that the supplied encoding is compatible with the type of the OpenCV image
if self.encoding_as_cvtype(encoding) != cv.GetElemType(cvim):
raise CvBridgeError, "encoding specified as %s, but image has incompatible type %s" % (encoding, self.cvtype_names[cv.GetElemType(cvim)])
img_msg.step = img_msg.width * cv.CV_MAT_CN(cv.GetElemType(cvim))
img_msg.data = cvim.tostring()
return img_msg
def imgmsg_to_cv(self, img_msg, desired_encoding = "passthrough"):
"""
Convert a sensor_msgs::Image message to an OpenCV :ctype:`IplImage`.
:param img_msg: A sensor_msgs::Image message
:param desired_encoding: The encoding of the image data, one of the following strings:
* ``"passthrough"``
* ``"rgb8"``
* ``"rgba8"``
* ``"bgr8"``
* ``"bgra8"``
* ``"mono8"``
* ``"mono16"``
:rtype: :ctype:`IplImage`
:raises CvBridgeError: when conversion is not possible.
If desired_encoding is ``"passthrough"``, then the returned image has the same format as img_msg.
Otherwise desired_encoding must be one of the strings "rgb8", "bgr8", "rgba8", "bgra8", "mono8" or "mono16",
in which case this method converts the image using
:func:`CvtColor`
(if necessary) and the returned image has a type as follows:
``CV_8UC3``
for "rgb8", "bgr8"
``CV_8UC4``
for "rgba8", "bgra8"
``CV_8UC1``
for "mono8"
``CV_16UC1``
for "mono16"
This function returns an OpenCV :ctype:`IplImage` message on success, or raises :exc:`opencv_latest.cv_bridge.CvBridgeError` on failure.
"""
source_type = self.encoding_as_cvtype(img_msg.encoding)
im = cv.CreateMatHeader(img_msg.height, img_msg.width, source_type)
cv.SetData(im, img_msg.data, img_msg.step)
if desired_encoding == "passthrough":
return im
# Might need to do a conversion. sourcefmt and destfmt can be
# one of GRAY, RGB, BGR, RGBA, BGRA.
sourcefmt = self.encoding_as_fmt(img_msg.encoding)
destfmt = self.encoding_as_fmt(desired_encoding)
source_type = self.encoding_as_cvtype(img_msg.encoding)
destination_type = self.encoding_as_cvtype(desired_encoding)
if sourcefmt == destfmt and source_type == destination_type:
return im
# First want to make sure that source depth matches destination depth
if source_type != destination_type:
# im2 is the intermediate image. It has the same # channels as source_type,
# but the depth of destination_type.
# XXX - these macros were missing from OpenCV Python, so roll our own here:
CV_CN_SHIFT = 3
def CV_MAKETYPE(depth,cn):
return cv.CV_MAT_DEPTH(depth) + ((cn - 1) << CV_CN_SHIFT)
im2_type = CV_MAKETYPE(destination_type, cv.CV_MAT_CN(source_type))
im2 = cv.CreateMat(img_msg.height, img_msg.width, im2_type)
cv.ConvertScale(im, im2)
else:
im2 = im
if sourcefmt != destfmt:
im3 = cv.CreateMat(img_msg.height, img_msg.width, destination_type)
cv.CvtColor(im2, im3, eval("cv.CV_%s2%s" % (sourcefmt, destfmt)))
else:
im3 = im2
return im3