cv_bridge

cv_bridge contains a single class CvBridge that converts ROS Image messages to OpenCV images.

class cv_bridge.CvBridge

The CvBridge is an object that converts between OpenCV Images and ROS Image messages.

>>> import cv
>>> from cv_bridge import CvBridge
>>> im = cv.CreateImage((640, 480), 8, 3)
>>> br = CvBridge()
>>> msg = br.cv_to_imgmsg(im)  # Convert the image to a message
>>> im2 = br.imgmsg_to_cv(msg) # Convert the message to a new image
>>> cv.SaveImage("this_was_a_message_briefly.png", im2)

cv2_to_imgmsg(cvim, encoding='passthrough')

Convert an OpenCV cv::Mat type to a ROS sensor_msgs::Image message.

Parameters:

• cvim – An OpenCV cv::Mat
• encoding –

  The encoding of the image data, one of the following strings:

  • "passthrough"
  • one of the standard strings in sensor_msgs/image_encodings.h

Return type:

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 cv_bridge.CvBridgeError on failure.

cv_to_imgmsg(cvim, encoding='passthrough')

Convert an OpenCV CvArr type (that is, an IplImage or CvMat) to a ROS sensor_msgs::Image message.

Parameters:

• cvim – An OpenCV IplImage or CvMat
• encoding –

  The encoding of the image data, one of the following strings:

  • "passthrough"
  • one of the standard strings in sensor_msgs/image_encodings.h

Return type:

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 opencv_latest.cv_bridge.CvBridgeError on failure.

imgmsg_to_cv(img_msg, desired_encoding='passthrough')

Convert a sensor_msgs::Image message to an OpenCV IplImage.

Parameters:

• img_msg – A sensor_msgs::Image message
• desired_encoding –

  The encoding of the image data, one of the following strings:

  • "passthrough"
  • one of the standard strings in sensor_msgs/image_encodings.h

Return type:

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 standard image encodings

This function returns an OpenCV IplImage message on success, or raises cv_bridge.CvBridgeError on failure.

imgmsg_to_cv2(img_msg, desired_encoding='passthrough')

Convert a sensor_msgs::Image message to an OpenCV cv::Mat.

Parameters:

• img_msg – A sensor_msgs::Image message
• desired_encoding –

  The encoding of the image data, one of the following strings:

  • "passthrough"
  • one of the standard strings in sensor_msgs/image_encodings.h

Return type:

cv::Mat

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 standard image encodings

This function returns an OpenCV cv::Mat message on success, or raises cv_bridge.CvBridgeError on failure.

class cv_bridge.CvBridgeError

This is the error raised by cv_bridge.CvBridge methods when they fail.

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