Kirielson's profile - activity

I fixed it with two things,

First it's cv.Line not cv.line

Second of all, this is how you would want to do the listing:

for i in range(min(len (currFeatures), len (self.prev_draw_features))): # Find out which index is shorter
    currpoint = currFeatures[i]
    currpoint = (int(currpoint[0]), int(currpoint[1])) #Also code out the same setup for prev_draw_features
    cv.Line(new_image, currpoint, prevpoint, 123, 5)

What you probably want is:

for ((x,y), (px,py)) in zip(currFeatures, self.prev_draw_features):
        cv.line(new_image, (px,py),(x,y),cv.RGB(125, 20,200),5)

I'm trying to iterate from two tuples to create a line connection previous points to currents points.

    for (x,y) in currFeatures and (px,py) in self.prev_draw_features:
            cv.line(new_image, (px,py),(x,y),cv.RGB(125, 20,200),5)

Which then leads me to this error:

[ERROR] [WallTime: 1309631642.294530] bad callback: <bound method="" cached_subscriber.callback="" of="" <__main__.cached_subscriber="" instance="" at="" 0x2bbb290="">> Traceback (most recent call last): File "/opt/ros/diamondback/stacks/ros_comm/clients/rospy/src/rospy/topics.py", line 563, in _invoke_callback cb(msg) File "**", line 70, in callback for (x,y) in currFeatures and (px,py) in self.prev_draw_features: NameError: global name 'px' is not defined

Is it possible to iterate between two tuples at the exact same time, or will I need to construct a new variable to iterate between the elements. Keep in mind that the tuples may not be equal (which probably negates my "and" statement.

Thanks.

Okay I solved my problem. It seems for Python, at least where I'm running ROS's OpenCV for Python, the images and the pyramids are mixed up if you got the error: error: pyramid A has insufficient size. So wherever you would put your images, you would then put your pyramids and viceversa.

Short version: Hello, I was wondering what cvAlign does in the inner functions.

Long version: I've been looking at cvCalcOpticalFlowPyrLK code and there's a function

pyrA = cvGetMat( pyrA, &pstubA );

if( pyrA->step*pyrA->height < icvMinimalPyramidSize( imgSize ) )
    CV_Error( CV_StsBadArg, "pyramid A has insufficient size" );

which then leads to this:

static int icvMinimalPyramidSize( CvSize imgSize )
{
    return cvAlign(imgSize.width,8) * imgSize.height / 3;
}

can anyone tell me what cvAlign does (is it bit alignment)?

I think you are looking for that function:

std::vector< MConstPtr > getInterval (const ros::Time &start, const ros::Time &end) const

The callback is for new messages. I guess it's just there because it is a filter.

Bump for awareness.

In the message_filter package, there is a cache function that allows you to store data for a temporary amount of time. How would you access this cache properly? I understand that the function in message_filter says for doing a callback but how would go and create this callback function for the cache. I want to access different parts of the cache.